04-27-2015, 09:27 PM
Join Date: Oct 2014
Total Cats: 0
Where's The Boost?
As my title suggests, I'm having some issues with my turbo as of late. I have a garrett GT2560 turbo. Predating this issue, I took apart my turbo and used exhaust sealant between the exhaust manifold and the block with a new gasket, between the mani and the turbo flange, and between my turbo and the downpipe with a new gasket. Previous to this I had to trim my turbo to intercooler hose some at the top because of a tear under the metal band clamp holding it to the turbo.
Symptom: boost builds to only 4 psi in 1st gear, and 3rd gear in all other gears after that.
Things I've looked at so far:
- Checked wastegate actuator. Turbo spins with it closed, and doesn't when I force it open.
- Checked performance without air filter, worked the same with the filter.
- Removed vacuum line to wastegate actuator to see if I could build more pressure at all, still no more boost than before.
- Capped off exhaust with my hand, decent pressure built up, and no noticeable leaks caused.
- Looked at all exhaust couplings for soot, found nothing.
- Listened for boost leaks, everything sounds good.
- I've checked for play in my throttle cable and it looks fine.
- Checked turbo turbine for play or hard turning but it's pretty solid, and spins just fine. Only issue is a small blemish on one blade that has been since long ago.
I have two things I've thought of so far:
- Maybe there's an obstruction in my exhaust around the cat, I would think not as the engine runs fine as it sits but worth a look.
- After trimming the intercooler inlet hose, there is a decent kink in the elbow just after the turbo outlet. I could try to trim more or to fit a different hose that fits better.
Does this sound familiar to anyone? Is there anything I'm forgetting? I feel like the kink in the hose SOUNDS like the issue but there was always a little kink. I think things are a little more drastic than before but it doesn't look completely closed off or anything. Rather frustrated as I was easily building up 8psi all day long, but with exhaust leaks. Car sounds great now but no more power...
Last edited by dansnyderECE2010; 04-27-2015 at 09:38 PM.