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Monday, December 15, 2008

GM 3.8L Plastic Composite Intake Manifold



When car manufacturers decide to do something goofy, like using plastic intake manifolds, we in the repair business do not get happy feet anticipating a stream of big repair invoices. The customers many times see us as somehow connected to these breakdown time-bombs, wondering why we didn’t anticipate trouble, and force the manufacturers back on the proper path of metallic parts more resistant to problems. In actuality, we in the repair business love maintenance work, and would like nothing better than to service vehicles for our customers with all potential fiascos handled before they strand our clients. We are not always given this option, either because the manufacturers don’t broadcast their engineering snafus, or the customer ignores our warnings, which brings me to the pictures above of a GM 3.8L plastic upper intake manifold.
A metal tube routed up through the lower metal intake manifold from the Exhaust Gas Recirculation Valve burns holes in the plastic manifold it extends into, allowing coolant to be mixed into the crankcase engine oil and combustion chambers. Unfortunately, the signs don’t always become obvious until the coolant contaminated engine oil destroys the engine. This plastic manifold was used on most 3.8L GM engines from 1995 thru 2005. The fix, involving replacement of the upper plastic (composite) intake manifold, gaskets, and peripherals is costly; but much less expensive than replacing the engine, which will have to be done if this repair is not completed.
I had three of these in the last week, which is how things go wrong in auto repair: in threes. The first engine was already ruined. The second made lifter noise in the morning, and was salvageable, as was the third. The first customer had driven the Pontiac from back East, which is much harder on the manifolds due to extremes in temperature. He said he had experienced no sign of failure until the vehicle simply quit on him. I figured if I put this out on the blog, it might get picked up in the search engine, as was my Honda Balance Shaft seal blog, and save some engines. When the hood is opened on one of these, you will not see this manifold. There is a plastic cover over the entire engine, which says 3.8L on it. It can be removed by unscrewing the oil filler cap and tube (counterclockwise). This allows the engine cover to be slightly tilted and freed from the rear fixture. Then the plastic intake manifold will be visible.
That’s all for this update from Nilson Brothers Garage, but if you’re appreciative of the information, here is a link to my new novel COLD BLOODED for Nook and Kindle. If you’re kind enough to read it and like it, please review it on the site you purchase it from. Thank You! Every little bit helps my writing gig. :)

261 comments:

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BernardL said...

One thing I can add for you to check with the info given is checking the exhaust back pressure in front of the catalytic converters. It may be you have excessive back pressure due to plugged up converters which would cause some of the maladies you described.

You're right that the ECM could still cause the problem. Also as you noted if the torque converter lock up solenoid stays on as you decelerate, it will stall the vehicle. You can test that just by unplugging the solenoid for a few days and see if the problem goes away. The cold start issues could be anything from worn injectors to simply low quality fuel. My guess would be the injectors.

Tony said...

Update to my previous email of Part 1 and Part 2. My mechanic after changing everything mentioned in part 2 email, finally changed the ECM/PCM which is the same unit in a 1995 Olds 88 3.8l and my car is FINALLY starting normal even on the coldest days and no more crazy in the blue moon stall/die issues.
Car is finally fixed.

Next update I mentioned in part 1 email posted earlier, my mechanic looked at the creamy substance and water droplets on the inside of my oil cap and said it was not a creamy buildup and it was more like frothy residue that was the same color of engine and not white in color. He said I did NOT have a intake manifold coolant leak and said any new car will have the light oil residue inside the oil car and it was just how any car would be from driving. He also said I had no external coolant leaks, no coolant in my engine oil, no lifter noise, and said sometime in the past the intake manifold gaskets were replaced since he could see the RTV silicone stuff in excess in places around that intake manifold that the factory would not have.
He did say just to be safe to monitor the engine oil and if any coolant loss or lowers from the full line on the coolant reservoir.
Again thanks for your blog. It looks like everything is fine on my car now but will continue to monitor the coolant just to play it safe.

Thanks Tony

BernardL said...

Tony, there should never be a frothy residue on the inside of the oil cap, especially with moisture droplets that you can tap out into your hand. An oil cap, even after the car is driven for miles, when you shut it off and pull the cap, it may have an oily sheen to it. It will not have moisture droplets. It will not be frothy as in creamy color either.

Unknown said...

I have a 2001 Buick with the 3.8 engine that made a sound like a gun shot, then the engine caught fire on back side of plastic intake. The intake was completely blowed apart. What cause this to happen ????

BernardL said...

Think about it logically, Eagles. How could I know the answer to your question from here on the Internet. Fuel leaks, backfires, leaking fuel injectors, leaking fuel pressure regulator... it could be any of these or none of these.

Unknown said...

Well, the aluminum UIM on 3800 Camaros do not have this issue, so not ALL 3.8L engines have this issue, luckily. ;)

Unknown said...

Hello Bernard,

I am writing because I believe I have an intake manifold problem. I suspect it is only the gasket.

I do not have any fluid mixing. However there is oil coming outta the back side of intake but has been leaking for years now, common problem and has not seemed to have gotten worse. It had also been leaking slight antifreeze outside the motor too however this seems to have gotten worse since my problem has begun. Seems like when running I have to add about 1/2 gallon every tank of gas which has been too frequently.

Back info: The car has been having a loss in power and sputtering as well as a random misfire code and I have replaced ignition system components as they tend to be common problems.

I am not sure if this is likely to be in upper intake manifold gasket or lower.

I suspect it could be air coming in messing with air/gas mix ratio but unsure how to test this or figure if it is this due to upper gasket or if this can even happen due to lower gasket.

Any thoughts are appreciated. Feel free to request any info I may have forgotten to provide, ect.

Sincerly,

DIO

Unknown said...

Also, it should be said that my 3.8 has the aluminum intake pleneum so it is alluminum and not plastic as it is in your picture posted at the begining of this blog.

BernardL said...

I'd like to help Brad, but you haven't given me the year, make, or model, and although you speak of codes, you haven't listed them.

You may have a weak fuel pump, or partially clogged injectors, or a host of things. I'll try and make a better guess, but I'll need all the codes set, and whether you've had the fuel pressure checked.

Tim said...

Hello Bernard,

Great blog. I have read this entire thread twice.

I am not a mechanic at all so please bear with me.

I have a 2001 Grand Prix GT (Not supercharged)with 150k miles. It was not accelerating in passing gear and I also heard a knock so I took it in. They said it was the cat so I had it replaced. Then they said the engine was still not getting power and needed to be replaced. They also said there was a knock.

I said what about the trans? They said it’s not the trans. They rebuilt the trans when they sold me the car 2 years ago.

They quoted me $1195 for an engine with 100k on it, to be purchased from LQK with a 6 month warranty, and 12 hours labor @ $85 to install.

I’m worried about the UIM and less so about the LIM. My questions:

Does $1195 seem like a fair price for this engine?

Did you say that only engines from the 1990s had the bad UIM problem? If so, does that mean that if I get an engine from 2000 or newer that should not be an issue? Should I avoid engines from the 1990s?

Should I have them make sure the UIM has been upgraded if needed, along with good gaskets and to replace them if they have not been (OEM UIM and Fel Pro gaskets)?

Approximately what would it cost to put in a new UIM and gaskets when the engine is not installed yet?

Is it possible that a used engine can have internal damage caused by a leaking UIM, even if it had been replaced at some point. Is that damage detectable?

Also, can a used engine have corrosion caused by Dex Cool that could cause problems later?

In general, should I avoid engine from the 1990s if possible?

Also, a guy at another shop told me you can get a newer model year engine if you swap out the manifold. Do you know anything about that?

As for the LIM, should I have them replace that, or at least the gaskets before installing the engine? Approximately what would this cost?

Do you think I should try to get a lower mile engine? How much more might it cost.
Also, can you recommend anything else I should have done before installing the engine?

Finally, this is my call, but I am debating whether or not I should replace the engine or just dump the car and buy something new. I’m not working now so I just want to buy some time until I get another job and can get financing and have more time to research a new car. I just don't have time for that right now.

Sorry for the length. Any advice would be greatly appreciated.

Tim

BernardL said...

Tim,

I don't install nor recommend used engine installation, so I have no advice for you on that, and a new or rebuilt one for the vehicle would probably cost more than the car is worth. Yes, it was the nineties with bad plastic intakes. In California, it is illegal to install an older engine in a newer vehicle. My only suggestion is now would be the time to nurse your old one along until you can get a new vehicle, without pouring money into it.

Tim said...

Thanks Bernard,

As for nursing it along, the shop is telling me not to drive it without a new engine, except for short local trips. I'll probably just put a replacement engine and hope for the best.

Tim

BernardL said...

Good luck, Tim.

Unknown said...

Hi Bernard - what an awesome blog! I am looking at buying an '04 Regal without the supercharger, 160k miles. The listing says: "There is a slight coolant leak in the back of the engine, very minor but wated to let you all know. You can smell it a little when the engine is hot and I have to add coolant ever month." Should I avoid this car, or are there things that should be checked and it can still be a great vehicle?

BernardL said...

They do have coolant leaks many times at the rear corners of the intake manifold, or at the crappy heater connections they use. The manifold job is over a thousand dollars. I can't tell you one way or another if it's a good buy without knowing exactly where the coolant is coming from, Phil. Get them to let you have it checked out on your dime if you're really interested in it.

Unknown said...

oil pump and oil pressure regulators can cause big problems.you should never see milky oil,that is usually intake problems that i have fixed during rebuild on my 98 monte carlo.but if you hear top end being rattly,check oil sensor and sometimes they die,meaning the car as protection because oil pressure is down.a stuck open oil pressure regulator will blow a oil filter seal and that means the valve is stuck or worn out on oil pressure reg.get the best gaskets,make sure your heads are straight,get up -graded plentum package and check oil pressure sending unit because light should show low oil pressure.

Unknown said...

i have ,as i said a 1998 monte z34.my front seal started leaking.i replaced,checked compression,all is good on that.gonna pull apart oil regulator because there should be no pressure on front main seal.put a redi-seal on balancer because of a groove.seal failed again.seal was rubbing right near edge of redi-sleevce.i have a different type this time but my question is why does anyone think this is happening.i have 30,000 on the rebuild.it has ran good with no problems.im thinking regulator or slack around oil pump gear letting oiul into this cavity.i am new to this forum and would greatly appreciate any help from experienced mechanics who have worked on these 3.8 litre engines.sincerely.Robert

BernardL said...

When a rebuild is done, it does not come with a new vibration dampener, hence the need to use a 'seal' over the grooved dampener, Robert. If it leaks after a special seal insert is installed, you'll need to get a new dampener.

Another possibility is a plugged PCV system not allowing proper venting of the crankcase. If the PCV system is clear and working, the engine itself may have excessive clearances, allowing for pressure build up in the crankcase, which will force oil out.

Unknown said...

I've got a 1999 Intrigue. It just started getting oil in the coolant. The oil shows NO sign of contamination. The engine also runs fine with no white smoke or any performance problem. Furthermore, I'm getting coolant pooling around the front center injector and also leaking oil in back at the passenger side of rear center cylinder. Am I safe in just replacing the upper manifold? I'm pretty sure it's not ever been replaced, but I am the second owner of this car. The fact that there is no coolant in the oil would seem to mean I haven't melted the EGR interface, but I will still check and get the metal tube if I find it doesn't have one. Anything you can think of beyond what I'm describing? Oil usage seems to be quite minimal which makes me thing the lower manifold is ok. I'd just hate to have the upper off and not do anything with the lower if it needs it. Doing this twice would be a Bad Thing.

I'm tempted to replace this myself this weekend as the upper manifold looks like it should take around half a day to do with allowances for issues on disassembly. Due to additional contamination issues I'm not at all sure I want pull the lower myself. I've already washed the engine to find the leak points, and would clean it again so I'm not nearly as worried about getting dirt into the valves doing the upper.

BernardL said...

Unknown - I know you don't want to do the job twice. If you take off the upper manifold, and do not see how the oil is getting into the coolant, you will probably have to take the lower off to find out how it is happening.

You are sure it's not transmission oil from the cooler, right?

Your other option is to buy a dye kit so you can find out where exactly the leaking is occurring.

Unknown said...

Does not appear to be transmission fluid. Transmission is full w/o contamination. If the systems got crossed I would expect coolant in the transmission due to pressure differential. Thing is, I'm losing very little oil. The crud is brown and does not smell like transmission fluid as well. I will order parts for both upper and lower. It would appear that there's a real chance the lower could be damaged even if it isn't leaking yet. I'll get a good quality metal gasket and an upgraded upper manifold so i won't have any more troubles. i may also power-flush the transmission on general principles. That should seriously reduce the chances of catastrophic failure in the expensive areas. My other car just lost its transmission with no warning so I'm going to try to preempt a second episode of this. (It was a Sable - a pump blew in the transmission. You can't even idle the engine in park w/o hideous noises. It's gone.)

Unknown said...

Ah, found what I think is the best from Felpro. The MS 98014 T for the bottom. It appears to be metal with ribbing to help seal any damaged areas, and the MS 95746 is what felpro has for the top. Reviews are VERY positive om the bottom gasket and good on the top one. I will make sure the other points of failure (EGR, heater connection) are also fully upgraded. I sincerely hope that will put an end to all my engine issues for a long time. Also I don't know why i'm being called unknown as I did log in with Google.

BernardL said...

Sorry Unknown. I would refer to you by another name if you had written one in the post too, but it's not showing on Google. It doesn't matter though.

As to the Transmission - it can leak trans oil into the coolant without coolant getting into the Trans.

Are you certain that brown gunk isn't just the usual contamination from the GM coolant? It has a tendency to turn into clumps of brown mud.

Remember, if you see any damage on the top manifold, it must be replaced as a unit.

Yes, Fel Pro is the best.

Unknown said...

I'm Jon btw. The gunk could be contamination from that orange crap. I know from vacuum flushing the cooling system plus coolant accumulation around the manifold there's some kind of leak - we pulled a lot of air through from somewhere. I'm getting coolant on the top of the engine around the plastic manifold. I've got new coolant in, not the crappy orange stuff, and I seem to be getting more and more crud. This could be some reaction with residue - I really don't know. The system was power flushed with the coolant change. I was not happy with the result There's no evidence of the orange at this point. I think what I may do is go ahead and get the gaskets, replace the upper and take a good HARD look at the lower and decide of I should pull it. That orange coolant is a disaster and if I have that much off, there's good reason to replace the lower because the orange coolant is known to eat that gasket as well as some of the metal. I'd like to have an engine that I can run with synthetic oil and get some decent mileage out of.

If I wind up with good access to the rear valve cover it might not be a bad idea to change its gasket. There's one very small oil spot that's reappearing and if oil isn't in the upper manifold it has to be coming from the valve cover. Those are the only two choices. I think it's the manifold because that's where the black line of leakage goes and there's no equivalent going to the valve cover. I'll tell you what, I'll use my phone and make a quick youtube video of the crud and engine and such. Should condense to under 30 seconds. and be worth a lot more than a thousand words. That could take some of the guesswork out of this.

A related issue - in searching online this transmission seemed to be much better than a lot of cars, but it's still front wheel drive and a point of failure. I'm going to power flush it on general principles. Is there anything else preventative I could do to help it? The fluid is clean and unburned right now. The only thing I wonder about, because I don't know the car very well yet, is there's a slight "bump" when I start out, probably the torque converter bypass. It's very slight and there's no slip or hard shifts in any gears.

Unknown said...

http://i.imgur.com/37dkIpR.jpg
http://i.imgur.com/VBJ7sTn.jpg

I tried to get something of the engine itself but that'll have to be done in daylight. What's getting me here is that I blew a head gasket years ago on a Dodge Neon and my coolant looked exactly like this. Unlike this situation, the oil was tan and sludge.

If this is GM orange coolant crud, I have to give them a major boobie prize for freaking me out.

BernardL said...

Jon, it could definitely be residual orange crud being cleaned from the inner block walls. You haven't mentioned looking at the underside of your oil cap. Any creamy residue or beads of moisture there means trouble with coolant contamination.

After flushing the transmission I would go with a full synthetic trans oil like Valvoline's.

Yes, while you have the top manifold off, that is the time to decide on the lower. Any sign of oil leakage, which is common on those manifolds too, and you should change the gaskets.

Unknown said...

Oil cap is fine. No evidence of flow in the opposite direction. Anyway, parts are all on order so I doubt I have much to say until I tear things apart.

Unknown said...

Thanks so much for your help. What I've done is gone to my mom's place for some vacation and I'm fixing the car with other transportation available. I just ran an acid flush to get the dexcool crud out - there was a huge amount. I found, as expected, that was the only thing holding the intake side together. Both manifolds were confirmed leaking before the flush and now they leak freely. So, I figure after 4-6 hours under the hood, I'll have a working car. It is currently undriveable but I don't have any carbon left in the engine due to all the leaks. I wish I could have flushed things for longer but the reaction with the crud was fairly violent. I may do a separate flush on the radiator and heater core to finish it, but at this point I think I've got enough out that I'll be ok w/o compromising expensive parts. I had the heater blowing very hot after my second water flush so fingers crossed I didn't clog something major with all the white flakes I got out of the thing.

Unknown said...

P.s. I got loads of brown sludge followed by lots of white flakes after I started in with water. I assume that's normal.

BernardL said...

You did all you could, Jon. I hope it goes back together working well. The flakes are usually the chemical reaction to the aluminum in the heater core, radiator, or manifolds.

Unknown said...

Two points on disassembly not covered in my documentation. #1, and it's a pain - there's a brace that is on the front of the TPS which blocks access to the front lower bolt to remove TPS etc. from the manifold. The top nut on the brace is removed but the bottom is directly behind the exhaust pipe and I can't move it. I have pulled the injector rails etc. and I'm about ready for the upper plenum. I have loosened the TPS so it's free etc, but that one nut is tight crud all the way down and I've gotten it off as far as I can with a crescent wrench. I'm very tempted to take this brace out and leave it out once I get things apart enough I can do it. It does not appear on any other engine pics I can dredge up of the 3.8. I may make another round. I'll try to shoot a pic and post in my next comment. It's like the Devil himself showed up at GM, said the procedure was too easy, and added this just for the entertainment value. This is not unique to GM.

Secondly, with my injectors off, is there a good cleaner I could use to get all the crud off of them. I've seen the ads for years of dirty vs. clean injector spray, and as long as they're off.... I'll try to post a pic of the injectors as well. Other than that brace, everything is proceeding according to the manuals etc.

BernardL said...

Keep soaking the nut in penetrating oil. You may have to use whatever you can to cut the nut off. It is never a good idea to disable brackets. I wouldn't get too crazy with cleaning injectors other than spraying and wiping with a fast drying spray like Berryman's Brake Clean and wiping if you're not replacing them. New o-ring seals usually come with the intake set.

Unknown said...

The easiest way to deal with that, dunno where I can post it some some other frustrated shade tree mechanic can find it. You loosen the whole plenum and everything else that you normally pull minus the problem nut. Then once it is loose you have enough play in it to pull it around the bracket and remove the nut with it out of the way. Just gotta lift it maybe 3/4". As for the condition of the engine....
Put that link down there back together and you can see what I found. Pretty bad, eh?

https://www.facebook.com/photo.php?fbid=10206935793610051&set=a.1709865863196.96227.1134574630&type=3

BernardL said...

I hope everything works out okay for you, Jon.

Unknown said...

Had to duck out of town on business. I'm back now and I hope to get everything together tomorrow. Major Dexcool damage to the lower intake as expected, though not as bad as some pics I've seen of it. Brake cleaner is doing very well to get all sorts of things off. The only thing that concerns me is how much oily gunk has gotten into the intakes. I'm having to get creative to get it out without getting dirt into my valve lifters etc. I did a lot of cleaning on the parts for a couple of hours today. Everything is apart now -- no more disassembly. Got the lower manifold so all machined mating surfaces are flat again, always a good thing. Only thing left is the engine itself which is going to get lots of paper towels wadded into places to protect them while I work. Reassembly should be a snap compared to getting this thing apart -- at least that's how it usually goes for me. I haven't done a repair myself this major for about 20 years, but I seem to be still up for it.

blue said...

O hope you still are doing this info thing. I have a 1998 Buick lasabre. Around 2003 the upper intake was replaced. I think this because the date stamped into it is 3/18/2003 and it's a delphi, so it's obviously newer than the car. I have a coolant leak and oil leak around the upper manifold gasket. No "milky substance on the oil filler cap or tube and car runs fine (just a little longer to start than most vehicles I've own though only by a second or two.should o replace the upper plenum and gasket or just the gasket and should I replace the lower gaskets as well? I thank you for your time

BernardL said...

Blue. It may be you'll have to replace the lower manifold too, along with all applicable gaskets. The mating surfaces may not be mating as they should any longer. A pressure test of the system should reveal where the leak originates from, without doubt.

Unknown said...

I recently changed my thermostat and now every time that I give it gas it's shooting water out of the top of the engine what is that problem now

Unknown said...

it was running hot but now it seems to be we're next to the throttle there is water leaking down on the engine and that's every time I throttle the engine water shoots

BernardL said...

You've blown the head gasket, Ashley. That's combustion gas building in the cooling system, forcing the coolant to geyser outwards. You've had a major failure.

Unknown said...

Could it be fixed and how much so I wouldn't be had but the car turns over it drives there's no milky white substance in the oil

Unknown said...

how much should it cost is it worth fixing

BernardL said...

Sorry Ashley, I have no idea how much or what exactly is wrong. You'll have to have it physically checked out and estimated. If it's an older vehicle, get rid of it. Anything that costs more in repairs than you can sell it for the day after it's repaired is not worth the gamble.

Gary said...

I have been reading your comments on the 3.8.I have just replaced head gaskets on a 1998 Regal. I had the heads done put it all back together still poured out white smoke.So I took off the upper intake to find it full of coolant and into the cylinders.So I am wondering what causes this with everything new and the heads done.
Signed
Stumped

BernardL said...

Gary, you never mentioned whether you changed the upper intake plastic manifold or not. Did you read the original post? Other than you getting the upper gaskets on wrong or didn't replace the faulty plastic manifold and make sure the lower one was in good shape, I have no way of knowing what may still be leaking.

Gary said...

I didn't replace the upper manifold. The gaskets seem to go on just one way.I will check the surfaces on the lower manifold. The lower gaskets are metal with rubber around all the ports should these be put on with silicon

BernardL said...

Gary... the point of the post is to tell you the plastic GM upper manifolds are faulty. If you don't replace them, they LEAK coolant. Read the initial post.

Unknown said...

Hello Bernard. I know this blog hasn't been replied to in 3 years now but I am having some issues and really like this motor. Thank you for your dedication to putting this info out there. I have a 2001 impala ls 3.8 series II. I would appreciate a conclusion on this car as I just bought it. So I've noticed sludge all over water pump side so no surprise to me when I see some drips under car. Front passenger. Lower rad hose dripping at clamp and overflow reservoir has a crack in the bottom. Thank god for hydraulic lifts. Now here's where it gets weird. I am noticing the coolant I add turning dark. Maybe some shiny, in the overflow bottle. And after driving on highway engine white smokes very small amount by or under front exhaust manifold. So are the two mixing together or? Am going to drain or flush coolant anticipating sludge was considering doing the lower gasket as well. Do you think upper should also be changed along with the head gasket or am I safe enough just changing the lower? Temp holds at operating one cooling fan does not work am diagnosing. Seems to be a very slow leak hasn't needed much coolant. Have been checking oil, a little dark now but no mocha milkshake I've noticed on the engine cap or dipstick. Was going to change oil after repairs. Only other question is valve chatter... are we talking pretty normal sounding little ticking or louder lifter sounds? When on the lift I put head by block and did hear some lifters but when above or with engine cap off it is hardly noticeable, especially when the fan kicks on. Assuming no worries there? No lights whatsoever, oil pressure or anything. I was going to pressure test rad but was curious about possible internal coolant leaks on the front side considering it only seems to be smoking around the exhast manifold. Any advice is appreciated. The car was 1650 I am willing to put in a few hundred to prevent the dreaded problems. If anything I've seen a touch of white smoke on a cold evening start. But this isn't acting like any head gasket I've seen.
Extremely slow leaks on both if anything missing from oil
Coolant is dark as if dirty and sludged but I believe oil turns the coolant mocha-y not dark with a hint of shiny (as normal coolant looks in the sun.) The sludge I've mentioned is dark in color similar to coolant color.
So overall should I mess with the head gasket or is a flush and fill first a good idea? Im thinking about flushing and filling to see if it still gets dark and seeing if I can save the gaskets. And changing oil, but if I were to have to do the gaskets I'd want to do all that after the gaskets obviously. If lower could allow oil into coolant I'd only do that. If heads start like this it's news to me, usually just dump all coolant into pistons/valvetrain or lots of oil into coolant in my experience.
Thanks for your time and advice sir.

Jesse

BernardL said...

Jesse, you need to stick with the basics. If there are no coffee colored signs of coolant and oil mix, pressure test the cooling system and fix all leaks, including cracked overflow tanks, bad hoses, and flush the sludge, etc. CHANGE the oil and filter. That should have been the first thing you did. Fix the fans not working, and drive it locally until you can determine it doesn't need a new engine. If it works well for a couple thousand miles, change the oil and filter again. Keep doing so until it either conks out or stays in decent shape. Monitor the computer for codes at each oil change.

Unknown said...
This comment has been removed by the author.
Unknown said...

I have a 1999 Chevy Lumina 3.8 V6 and I drove it to work had no signs of anything wrong with it turned it off went to work got off work went to start my car it wouldn't start had it towed home the tow truck guy works on cars he said go ahead and crank it over while I looked under the hood as soon as we crank it over a whole blew right through the intake manifold thought I blew his head off but I ended up buying the part from rockautoparts.com for $78.33 after shipping and all it comes with a Rings gaskets the whole nine yards so hopefully I can get this fixed up and on the road soon. Rockautoparts.com has very affordable car parts for those who cannot afford it but they are new or remanufactured for half the price you would pay at an auto parts store or from the actual manufacturer themselves

BernardL said...

I doubt that's the only thing wrong with the Chevy, Tabitha. You'd best be careful you don't have leaking fuel injectors along with a blown manifold.

Unknown said...

Hi, thank you for your information.

I have a 2004 Buick Park Avenue Base. Oil is getting in my antifreeze. I spotted it in the Coolant Tank. There is no coolant in the oil and the engine runs great with no smoke coming out of the exhaust. Is it possible for a leaky Upper Manifold Gasket to cause this problem? Any information will be appreciate. Thanks George

BernardL said...

George, it's more likely your transmission oil cooler (part of the radiator) is seeping into the coolant tank. If the intake manifold was leaking, you would have a creamy residue on the underside of the oil filler cap.

Unknown said...

Hello... I just has the composite cover explode on my 2001 buick regal ls... I bought it with a salvage title bc it had been wrecked in the rear. But I am curious if I should pit the work into fixing it or buy this 2000 honda accord I found with 220,000 miles for $600. I am curious to your professional opinion.

Unknown said...

Pull your heads and send them out as well. Have them machined and a valve job done replace your lower intake and gasket, change upper intake gasket and egr gasket and thermostat gasket. Just get a fel pro gasket kit with it all in there. You need the valve job since you're all contaminated and your heads sound due with the severity of your explanation. Good luck

BernardL said...

Unknown - Good advice, but a gamble.

If the Honda checks out, and you change fluids regularly, it would probably be your best option.

Brendan Ve said...

Is this thread still active?

I have a 2002 monte carlo with the 3.8. I see there was a hole melted into the top of the intake right behind the throttle body. It melted the wire loom a little but not the wires.

Obviously replacing the intake is a fix but whats the cause?

carsmoker said...

Thanks Bernard. Your post tells me what I need to do. That is let go of my 2000 Buick Park avenue. Family owned since 2004. It has over 200k miles on it with very few issues. Thankfully it was on a family farm and maintained well, sometimes by myself as farmhand. It has had a coolant loss issue for a long time though. Just wish we had info sooner.

carsmoker said...

By the way, Smoker is my maiden name, not due to car issues. Initials spell car. worked on Smoker family farms. Good luck people. Excellent cars if issue corrected early.





Unknown said...

2005 Chevy monte carlo 3.8. New lower intake manifold and gasket. New upper plenum and gasket. Water leaking out the throttle body. Upper plenum mounting bolts are in rough shape. Thread inserts in two holes. Need replacement bolts. Who sells them?

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