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Saturday, June 4, 2011

PO171 & PO174 Code Cause In Ford 6.8L Triton Engines



Because of e-mail inquires about a very common problem with PO171 & PO174 Lean Right Bank codes on the 6.8L Ford V10 Triton engine, I made this movie to illustrate the most likely suspect. A customer’s 1999 Ford F250 Super Duty truck with 6.8L Triton engine came in with the check engine light on,  and the engine loping (revving up and down in RPM). The PCV hose running  from under the front center lower throttle body to the right valve cover PCV valve (Crankcase Ventilation Valve) deteriorates where a sharp bend in the hose routes the hose to the valve cover. Once this bend in the hose rots and causes a vacuum leak many performance problems crop up – loping engine, lean miss, stalling, high idle speeds, hesitation, power loss, and the PO171 & PO174 code combo. The fix I do for this is to change out the sharp bend with a plastic connector. It’s a little time consuming but the hose never causes the same problem again.

The second part of the movie pertains to taking off the individual coil assemblies, spraying into the spark plug hole, and allowing a soak period before removing the spark plugs. These 6.8L & 5.4L Ford engines are infamous for stripped threads and actually blowing spark plugs out of their holes. Replacing them even with careful precautions can end in having to install thread inserts when the threads get damaged during removal. The Timesert 5553 repair kit is the best tool set for repairing these potential disasters.

That’s all for this update, 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. :)

28 comments:

Charles Gramlich said...

I smell academy award, man! :)

BernardL said...

Yeah, Charles, I finally got another one of these in the shop to illustrate the problem I've answered in E-mails generated from my other Ford posts a bunch of times. It's hard in a regular work day to find the time for setting this stuff up in my pursuit of acting honors. :)

whydibuy said...

Incredible how stubborn those Ford engineers are.

With all the grief the aluminum heads cause people and all the ill will it generates, those engineers refuse to change back to cast iron and admit defeat.


I would never buy a aluminum head vehicle. Aluminum is good in certain applications but its not good at a small level like threads. There, aluminum reveals its weakness among metals.

BernardL said...

You can't buy a vehicle anymore with a cast iron head, Whydibuy. While I agree with you about the problem, it seems only certain applications have trouble with this specific blow out. The fix would be to sleeve the spark plug holes on the assembly line similar to the fix the Timesert kit uses to fix the problem now.

I guess with mainly the 8 & 10 cylinder 5.4L and 6.8L engines being the most susceptible, Ford thinks the reinforcement too costly. Like you, I believe the animosity garnered from unhappy consumers far outweighs the expense of them making this right. Just a head job on an F250 or F350 costs in the three to four thousand dollar range.

howdew said...

Saved me a bunch of cash, my F250 has been running bad for a few months. I saw this on you tube went to the hose, it was cracked. 20 bucks later my 99 F250 V10 runs like new.
Thanks

BernardL said...

Thanks for the update howdew. I'm glad it helped.

BernardL said...

ATTENTION! For those of you who have suggested I add a donation gizmo to my blog so I may get some recompense for my efforts, I have an alternative since I hate the word donation. Here’s a link for my new novel COLD BLOODED’s pre-order page. It comes out November 22ond, but you can get a look at it there and pre-order it. If you like action/adventure fiction, take a walk on the wild side with COLD BLOODED. That way my publisher finds happiness and you can say thank you while getting something in return. :)

COLD BLOODED

BernardL said...

COLD BLOODED on Kindle

BernardL said...

My novel Cold Blooded is now on Nook too.

COLD BLOODED on Nook

Ruby said...

Thank you for the video. I was in Louisiana where they charged me hundreds of dollars to correct the problem and it didn't work. A short time later I pulled it into a KY garage and spent hundreds more and still didn't get the problem resolved. I decided to try and research myself tonight and your description of symptoms matched mine spot on. I watched your video and looked under my hood and there it was.....a crack in the hose. I'm thrilled to know that when I wake up tomorrow I can correct the problem once and for all. Thanks again.

BernardL said...

Thanks for commenting, Ruby. That's a shame you were unable to get it fixed at either shop... and embarrassing.

Unknown said...

thank you for the video, my 1999 F350 had exactly problems as described by you, saved me a ton of $$ !
I have another question if I may: after replacing the 90 degree hose with a new original Ford part ($45.- in Canada !) the engine is running way way better but still revving up from 800 to 1000 rpm when idling, should I check the straight lower part of that hose to the valve cover as well ?

cheers
Rik

Bernard Lee DeLeo said...

Rik, it may take the computer a few starts to adjust to the repair. You could try disconnecting the battery and reboot the computer. If it still is revving, you may still have a vacuum leak somewhere. A non flammable brake clean spray can pinpoint the leak. If the engine idle drops anytime you're spraying along the intake or throttle, you still have a vacuum leak. If the reset doesn't work, and spraying doesn't help, you may need to take it into a shop with a smoke machine to find the vacuum leak. There also can be other causes such as a bad idle air control, but I would drive it for a few days before doing anything else.

buaja said...

Thanks again Bernard !

I highly appreciate your advice and will follow your instructions .

Thank you for spending time and energy on a complete stranger's car problems, this is quite the experience, you are a true altruist.

Rik

Bernard Lee DeLeo said...

Thanks, Rik. It helps me too in keeping up with anything in the way of new pattern failures. I appreciate the update.

Unknown said...

Thank you Bernard. I followed your video and found the exact the same crack in the elbow on the Triton V-10 6.8L E-350 Econoline van.

Bernard Lee DeLeo said...

You're welcome, Unknown. Thanks for the update and comment.

Steve said...

I just want to say thank you! I have gone other websites after googling these trouble codes and they did not mention the PCV hose. Im glad I kept looking and read your page because I would have been throwing money at this truck for nothing! Thank you again!

Bernard Lee DeLeo said...

Thanks for the update, Steve. I'm glad you were able to fix your truck.

marty heid said...

You were right thank u I've do everything to fix this problem

Bernard Lee DeLeo said...

Thanks for the feedback, Marty. :)

Unknown said...

Thanks for the info. 99 f250 v10 po174 hose was cracked agane thank you.sr you rock Vincent from calif

gman said...

Cracked park plug and cracked hose thank you sir.

gman said...

Cracked park plug and cracked hose thank you sir.

Bernard Lee DeLeo said...

I'm glad it helped man.

Unknown said...

I have a 2003 and the hose is different and dont see any damage to it. They pulled the same lean codes. Could it be a fuel pump issue? I replaced the filter and the maf sender already.

Jeremy Hardy said...

I have a 2003 and the hose is different and dont see any damage to it. They pulled the same lean codes. Could it be a fuel pump issue? I replaced the filter and the maf sender already.

Bernard Lee DeLeo said...

The only way to confirm whether you have a fuel pump issue is to have a fuel pressure check. If it's at or below minimum specs, the pump needs changed. A bad one can cause lean oxygen sensor codes.