I have been having problems with my truck building and holding boost for a long while now. I have pressure tested, changed hoses and even used the soapy water to test every fitting. The only thing I could find was a very small hairline crack in the monifold. Since it was so small I didn't think much about it. Just installed and ATS 3 piece manifold the other day. When I pulled the stock one off I was amazed to see that the hairline crack that I saw was just the first 3/4" of crack. It ran along the bottom half all the way to the flange that bolts to the block. It had an 1/8 inch opening from the motor block, all the way up to the center and from there was just cracked. So the whole bottom side was wide open and not feeding the turbo. What a difference and something more for you all to check for. STOCK PARTS, BLAH.:mad2:

 

well one less stock part to worry bout eh?

 

Aint much of it left. The electronic controls, frame and body, that's about it. I'm almost there.

 

The stock manifolds are notorious for cracking even on stock trucks without the extra heat from modifications. Glad to hear you found your leak, sometimes they are a real PITA to find.

 

good to know, er, ah, bad to know, hell thanks for the heads up anyway! good to know.

 

Bad thing about this was that the crack was on the under side, so it couldn't be seen until the manifold was off the truck.

 

My dad's did the same thing...the crack was barely noticeable on the top (actually had some white residue around it), but the underside was cracked bad...it was almost cracked in half.

We found out his was cracked, because his was idling and blowing blue smoke...we both thought it was just tired at 230k. We replaced the manifold and not only did it run better, but it quit blowing blue smoke at an idle...we think that because the computer has no way to see fuel mixture, it is adding fuel as if there was enough air to burn it when there most likely wasn't.

The really wierd part was I had a 99 auto with 200k and the manifold looked new...and I drove a lot of interstate at better than posted speeds. His looked like it was 50 years old, and other than his is a 5spd, we had pretty near identical trucks (both 3.55s and 99 24-valves).

steved

 

Maybe it's the 5 speed thing then, cause mine was like his. Completely in half on the whole bottom side.