I am running an FP3065 and all of a sudden the car won't boost leak test anything over 2psi.

Things I have checked for:

Compression test perfect across the board.
Leak down test was OK. No cylinder had more then 3% leakage.
Eliminated the turbo and placed the tester off the TB and still won't go past 2psi.
Tried using a different boost gauge. Same. 2psi only.


Weird thing is, while doing the boost leak test we put a plastic bag around the exhaust tip, taped it and the bag blew up like a balloon.
Note the car was at TDC, meaning all valves should be shut but for some reason air is leaking through.

This is becoming frustrating not knowing this weird issue.
Any input would be appreciated.

 

You should pull off the cam cover and timing cover and double check the timing belt to make sure everything is still in time and it hasn't slipped a tooth on one of the gears.

Also, I don't know exactly how the Evo EGR system is setup, but I would think it's possible for the intake <--> exhaust path for EGR could be leaking.

 

umm, i thought tdc only referred to cyl. 1(or one cyl. at a time). there isn't any position that will allow all valves to be shut at once. you may be able to get either the intake or exhaust to shut(not even sure about that) but not everything across the head at once. also you have to account for any overlap on the cams as at tdc they may not both actually be completely shut yet depending on the cams.

 

The main boost leak test is done through the intake system to the TB. If the TB is closed, you should be able to hear a boost leak of the size you're describing. If you use a air bubble pumped to 35 PSI or so, you will eliminate the compressor noise and can hear perfectly. Do you have a good pressure tester?

 

Yes I have used this same pressure tester on my car in the past, with this turbo and on numerous other evos. We are pumping 100psi into the system. As Recompile mentioned, I am going to use an EGR block off plate tomorrow, perhaps it's stuck open or sticking.

 

100psi????? Why?

 

EGR vac line is off the solenoid.

Below the throttle body, on the side of the intake manifold.

Somebody had the same issue recently and I mentioned the EGR in that thread as well and it was his issue too.

I see it a lot.

https://www.evolutionm.net/forums/7232279-post35.html

 

Same thing happened to my car ^^^^^^

 

 

This.

Tony (was the other person)

 

A simple line will let that much pressure out? i find that hard to believe.. even tho it may be true

 

Will double check tomorrow and report back here!

 

No, I single vac line won't, but a line that keeps a EGR closed under pressure that came off will allow an open EGR to let that much pressure out.

 

What do you know.....vac line to solenoid was off. Thanks GSTM

Spool up feels better, will be boost leaking it tomorrow.