Is this junk or can it be fixed?

dogginred90 · February 16, 2008, 09:34:19 AM

Guys,
I started to tear my car apart to try to fix my backfire and stumble. Took the turbo off and look what I found. Is these cracks a big deal or not. I think it is junk please let me know your opionion on this. There are a total of three cracks when the turbo was rebuild last year it had one small one.

jimmy · February 16, 2008, 10:48:57 AM

Yea there pretty common, mine has them, But I'm thinking like you are, its considered junk to me. So I will go to a larger size turbo eventually. But meanwhile it'll be alright to run for now

dogginred90 · February 16, 2008, 01:44:14 PM

Would this make my car backfire above 8 lbs of boost with the 3 cracks or am i looking for something else.

GOT2B GM · February 16, 2008, 02:35:10 PM

Mine is cracked also, but it boosts to 10 - 11 psi fine.

dogginred90 · February 16, 2008, 03:02:01 PM

Any suggestions on what would cause the backfire and stuttering then.

jimmy · February 16, 2008, 03:13:49 PM

Mine does not backfire at all. This sounds like and additional problem. If no one knows exactley what the problem is, you might have to do the process of elimination on each individual items that have part of this particular problem. Good luck Red90.

TurboGTU · February 17, 2008, 04:33:50 PM

Quotebackfire above 8 lbs of boost

Could be the spark plugs, wires, ignition coils.

GutlessSupreme · February 17, 2008, 07:29:04 PM

What spark plugs are you running and at what gap?

Also, what brand/how many miles on spark plug wires, coil packs, and ignition module?

Also, and chip or injector mods?

I'm pretty sure all T-25s are cracked on the turbine side, but personally I haven't seen two and not that big for sure. The ones on my turbos were considerably smaller. I have plenty of other problems but those never caused any. yet.

TGP Nick · February 17, 2008, 08:54:12 PM

Quote from: GutlessSupreme on February 17, 2008, 07:29:04 PM
I'm pretty sure all T-25s are cracked on the turbine side

Last time I had my turbo off, it wasn't cracked. :laugh:

grinders_18 · February 18, 2008, 03:38:09 AM

X2....both times I had mine off, I had zero cracks.

cobracmdr · February 18, 2008, 05:32:47 AM

Did you clean off by the wastegate? The carbon and oil could have hid your cracks. If you shot blast it they will appear in most cases unless you have a new turbine housing on your turbo. Both of mine had cracks. I doubt that is your problem all it would do is bleed of a like .3 psi at most. Not going to cause drive ability issues.

Ken

dogginred90 · February 18, 2008, 11:17:57 AM

ok lets see if I can get all the answers here. Plugs are AC Delco, Gapped at .028, AC Delco wires, injectors are yellow tops(new), new FPR,used ignition module and coils off my 98 monte 3.1, bosch O2 sensor everything is less then a year old and has about 1,000 miles on them And I mean everything I have replaced all sensors. Spent over 4,000 so far on this car My chip is a kenny chip as well.

cobracmdr · February 18, 2008, 12:53:14 PM

My bets on the coil. Get a new one or a newer one with less miles on it from the yard. My GP was doing this hesitation thing on tip in throttle on the highway. I replaced a bunch of sensors and all it turned out to be was the Module or coils. I had a spare and swapped them in and it was fine.

Ken

grinders_18 · February 18, 2008, 01:01:25 PM

I'm going to bet either coil or ICM. My ICM and two coils were bad and they were making my car run like total ass. After I got them replaced, and after 9 months of replacing everything else, she ran great again. You said they were off your Monte, which would have a 3100, not a 3.1. Is there maybe a difference in the part? And no the 3100 and 3.1 are NOT the same.

dogginred90 · February 18, 2008, 01:53:57 PM

I check the part numbers and they were the same and sorry it is a 3100 my bad. Well i will just bite the bullet and get new coils and ICM. Hope that fixes it. If not I am going to replace the cam in the spring. Thinking maybe a bad lobe. Since this is a issue with these motors anyway 136,000 miles so it couldnt hurt.