A new problem--blowby near GP

[Michael Fowler]

Started up my truck this morning--20 degrees--started fine.
But I heard a noise like an exhaust leak. I saw a small jet of combustion gases coming out near the GP at the driver's side, front. I thought it might be a bad GP, so I swapped in a new one with no change.
I also have a small fuel leak in the area so that makes it hard to see--than and the cold temps make me not want to spend much time looking.

Have any of you seen a crack in the area I described? Is there a sucessful repair that does not involve pulling the heads?

 

[suv7734]

Haven't seen a crack there before. What was the seat on the glowplug like? Was there any soot or anything on the seat or threads? You also indicated a fuel leak. Is there any chance that injector is loose? That might account for the combustion leak as well as the fuel leak.
Just some thoughts.

 

[Agnem]

Something around the intake manifold gasket maybe? I realize there shouldn't be anything shooting out there, but that seem is in the vacinity.

 

[towcat]

scarry part is that if it's in the vicinity of the GP and injector, that's precup territory. cracking is a part of life in that neck of the woods, and that one doesn't sound very good at all.

 

[Diesel JD]

You sure its blowby from there and not from the nearby dipstick tube or what looks like blowby but is actually white smoke from your fuel being burned on the exhaust manifold....also ahve you checked the injector. I had a combustion leak there once to...made a very loud rapping sound.

 

[6 Nebraska IDIs]

I had a terrible fuel leak on one injector in my red truck, and it smelled NASTY, burnt rubber almost, and had a smoke coming off of the top by the GP. It was burning the fuel off from the heat. Fix the fuel leak and then see if it still does it.

 

[Michael Fowler]

Thanks for the replies.
The leak is no nowhere near the dipstick, so no possible confusion on that point.

I was hoping it was a loose injector, so I loosened the fuel line and tightened it--only about 1/16 turn or so--no change in the leak.

Fuel dribble makes looking at the leak area difficult--as does this miserable cold. I will check and report back what i know something.

 

[icanfixall]

You may need to pull that injector and see if the copper gasket is cut. If so you now need the seat cleaner to mill down the damaged seat in the head.

 

[Michael Fowler]

After the emotion of "What another problem?" subsides, I may decide to repair it (again) after all.
What sources and costs do you guys see on remanufactured/ good used heads?

If I go that route, I end up with an extra head that I can bolt onto my extra block and (maybe) begin to cobble up some manifolding for a twin turbo idea.....

 

[subway]

you think the glow plug threads could be damaged like if someone drilled one out before you?

 

[Michael Fowler]

Jred,
I'll certainly look, but there has not been a problem there before. I've had the truck for 14 years and 200,000 miles.

 

[HR20]

I had a similiar problem several years ago when replacing glow plugs. Not a gush or spray but a very slight bubbling around one glow plug (just happened to see it). Pulled the GP and put anti sieze on the threads (overlooked on instal). Solved the problem. Hope it's not anything major.

 

[Michael Fowler]

AN UPDATE!!!
Today, I cleaned the area around the glow plug and looked with a hi intensity light---nothing, maybe a very slight pore on the casting about 1/16 inch in diameter.
I started up the truck and used a water spray to locate the leak--not at that pore hole, but coming from around the GP threads. I pulled the GP--the threads on the bottom half look slightly flattened--I do not know why. Remember--this is the second GP in this hole.
As a diagnostic aid only, I wrapped the GP threads with teflon tape and reinstalled it. When the engine started, the noise was gone.
OK, so I have isolated the problem to the GP threads. What is the long term solution?
Will an extra heavy layer of never-sieze, as was suggested above, provide long term sealing?
I am hesitant to even try a threaded insert--too much chance of cutting into the PC chamber, or at least getting cuttings in there.
Has anyone else seen this?

I am so happy, its not the head--at least I think (HOPE) it can be repaired w/o removing/replacing the head.
Good news!!! ( I think)

 

[smoking89IDI]

With that Teflon on the threads won't it interfere with the grounding of the plug and put less current to it like a bad ground? Could you test it with an ohm meter compared to a known good plug for comparison. I know that was just for diagnostics but if it helps with no reduction in current would it be a problem to leave it on?

 

[Diesel JD]

I'm glad it wasn't a major engine problem. I have no idea what to say about fixing this issue. With the 6.9 system the grounding doesn't really matter, even if that glow plug didn't work he'd still have no problem starting it with the 12V glowplugs and the manual toggle. You could probably clean up the threads with a tap, but you'd want to keep the cuttings from falling into the motor. Don't think there would be any chance of damaging the precup...but I don't have any experience or qualifications to be 100% sure.