Well, I guess this thread can be my way of venting off steam I've had for the past week. I was aware that the factory seals in the throttle body are completely worthless, thanks to mitsu I went ahead and ordered the mil.spec seals so that I could replace the factory ones in my car. Little did i know, I develop a severe boost leak lik 2-3 weeks ago. Supposed to be hitting just past 1.5bar on my stock mitsu gauge but start only hitting 1.2, 1.3, then in the last week, i can't even hit 1.0. The car feels so bad its disturbing.

So time to do boost leak test and besides a leak where my mbc was hooked up and some leakage out of one of the ic pipe connections, all you hear is air flying out of the throttle body. You can already hear it leaking when there is only 2 psi in the system and by 20psi, once you remove the hose, the air is gone. I'm pretty sure this is whats been preventing my new Truboost gauge I got in the car from reading right. I just can't believe in a span of a week it seems like, the leak went from a minor problem to this disaster. 90% chance of leaking from factory imo is retarted... I guess to everyone else, check your tb's to see if they are leaking.

 

so what your saying is that after you installed the TB's seals the leak went away?

 

The new seals should take care of that leak. I'm waiting to get them installed.

 

throttle body shaft seals are easy peesy. Just do it your self.

 

DUDE I'M in the same boat as you my throttle body is leaking like crazy. I can't feel boost at all. It pulls as hard as a horse pulls an amish wagon. I just ordered my TB seals though.

 

the sad thing is even though my car is running like absolute horsecrap, it still manages to get the job done merging and etc etc. So I can't imagine how it will feel boosting full.

 

Yes this boost leak is horrible.. i pumped about 20 psi in and found a small leak in the UICP (fixed) then checked all other locations for anything...THO it was hard to hear ANYTHING cause it sounded like a compressor hose had a hole in it the way this TB was spitting air.. in about 30 seconds 20psi is gone... And it has to be the issue with the Truboost due to that when we pump air in to leak test her.. the guage is reading accurate.. SO with that said problem found and will be fixed..

 

yeah same boat waiting to get my seals in from milspec... should be here today

 

hopefully it fixes your problem

 

Tb's leak in alot of evos. I did a boost leak not long ago and heard a slight hiss from my tb. At 20 psi it would leak about 1 psi every 5 sec, it wasnt very bad. The seals should fix your problem.

 

need some help I'm completely stumped now. Changed the seals with the mil.spec ones and what do you know car is still running like crap. So figured that they were leaking from the seals again. I'm doing a test now and I hear air coming out of the P hole where the 2 other vacuum hoses are. Is air supposed to be coming out of here? Last time I did a test, I didn't hear any air coming out of here but now i do.

 

Those ports on the top of the throttle body are for EGR and Evap stuff. When I eliminated my EGR system, to include the valve, I just capped those off. When I do a boost leak test I can see the caps swell just a bit. You may have a faulty sensor at the end of one of those vacuum lines which is allowing boost to leak out. Take them off and cap them and zip tie them and then perform the boost leak test. If all is well then you know where your problem lies. Let me know if I can help you out in anyway.

Josh

 

thanks for your help. Right now the leak is first coming from the gasket. Took the gasket off double check to make sure its on right and now tightening it up. Will let you know if leak is gone.

 

Which gasket?
The Tb gasket?

 

yes the tb gasket. My retarted little air compressor is only able to pump in 9psi so tomorrow night I'm borrowing a friends air compressor and will resume boost leak testing. I'm about to give up though, this is so stupid. Have a feeling it is still leaking from the throttle body seals.