Thread: Solve the puzzle..

Needing some input on what many people I talk to are calling a strange problem.

A few months back I was driving my turbo gp down the interstate and go to pass someone. While i was in boost i had a the #3 sparkplug close(no gap) I get the car home and discover the problem but really don't know what to think about it. I replace the spark plug and everything sound and runs great... until. A couple weeks ago i went to visit my parents and once again on the highway and passing someone my SES light starts flashing again and the engine was running rough like it had the previous time. So sure enough i pull the plugs to find that #5 had closed just like #3 had before. I baby it home after getting the plug fixed and decide to change plugs. I got them changed only this time i can hear a slight ticking noise that increases with rpm. After everything i've read and from what car people have told me is that there is nothing else that could have closed the gap on the plugs except for a chipped piston. So i really don't have the $ right now to change pistons or really for gaskets to pull the heads and look. But i got to thinking that if I had chipped the piston that surely it would have done damage to the turbine wheel of the turbo. So i pull the turbo off and look at the exhaust side and it looks as straight and true as the day i got it. Had even a small piece of the piston gone through it those small fins would have had some damage.

Now for your input!
After taking the plugs back out of those trouble pistons they seem to have more of what i'll say to be oil on them than the rest.
What should i be looking for? possible bad valve seats? bent pushrod?

FYI both times it happed was under boost(under 10 psi.)
AFR was right where it should have been for PE
Timing seems to be at a good point with no KR registering on my scanner
And i am intercooled....


Solve the puzzle and Scott will buy you a lolly pop!

Thanks guys

If you could sweet talk someone into letting you borrow a borescope, that may answer a lot of questions for you.

Thinking about it, might not be right, might be wrong, never heard of it happening, but, could it be possible that the cylinders had a compression build up of some sort and with the extra force, push the gaps closed. Probably unlikely, but just a thought cause it happened while he is passing someone.

It's also "very" possible that some carbon buildup could have caused the gaps to close. But the ticking may be something more serious.

If you could sweet talk someone into letting you borrow a borescope, that may answer a lot of questions for you.

It's not even funny the number of places i've called looking for one. probably well over 15

Is there any damage to the plugs? Look on the grounding strap if it looks smooth should be ok but if there is chips then im sorry

They were closed but were clean. And once again the turbo fins would have taken a beating

It's also "very" possible that some carbon buildup could have caused the gaps to close. But the ticking may be something more serious.

Also considered this, i just need a sure way to tell.

What would cause the excessive oil in those cylinders though?

Only two things would cause excessive oil. Valve seals, but they would only show after the car has been sitting a while. If it's smoking at all, I'd vote for a bad ring, which may indicate a chipped piston.

Just a guess, and I could be wrong, but the first thought I had was worn bearings, Mains, Rod, Wristpin, or all three. How many miles does this car have on it? If it's over 60,000 on a turbo that's been rode hard and put away wet, as we say here in Texas, it might be time to open her up!

If it was mine, I'd park it and ride a bicycle if I had to until I found out what was wrong. This sounds like one of those problems that just gets more expensive by the day.

Just a thought.

-Ralphie

I bought the engine from ed about a 11 months ago and he said it had less than 10K miles on it.

And once again has anyone ever known of someone who had chipped a piston and not damage or even scratch the turbine wheel of the turbo? Thats what seems odd to me.

I don't want to speak ill of Ed, WHATSOEVER......but I did receive an engine from him at one time that had the good ol' #3 cylinder chipped. He took care of it though.

I wish I could help you out...I also would figure that the turbo would take damage from a piston chip. Does the car smoke at all or anything that would indicate a major problem?

I donno about 0 turbo damage, but i've known of many people (especially on ClubGP) who have had 0 cylinder wall damage and have had 0 valve/head damage from chipped pistons. With that said, i'd say it could be very possible to not have turbo damage too

Look at the metal thickness on you examples above. The fins on the turbo are about the thickness of a couple of pop cans and very easy to bend with your fingers if you wanted to.

I can see where you're coming from Kent....Inertia can bend the fins on a turbo.

I talked to Chris last night and gave him some ideas, hopefully something pans out for you.