Where are/were YOUR boost leaks?

[razrman8]

Post your previous boost leaks that you have had and how you fixed them. Or ones that you do have and plan on fixing. Mention things like how you found it and how much of a difference that the leak was causing.
I think that this thread can turn out to be highly informational.

 

[richard33]

I had a leaky BOV. I didnt even know until I got a Tial when I got new intercooler piping done. The boost went from 27lbs to 40lbs without touching the boost controller . The headgasket lost the battle.

 

[gusu]

I had several bad vacuum lines and a failed egr causing problems before I deleted them.

 

[MY1GDSM]

Throttle body shaft seals they tend to dry out after 15+ years... . Some how managed a long tome ago to blow out a Intake manifold gasket once... Everyone should do a Boost leak test occasionally especially if they have noticed a loss of power or their boost drops off from normal...

 

[907gs-t]

On mine I would get the P0420 code periodically ever since I bought the car so first I replaced both O2 sensors then the cat-back with the cat & then the O2 housing with the downpipe when I replaced the turbo & it would still show up now & again so I replaced the exhaust manifold last & when I did that I noticed my new turbo to manifold gasket was leaking so I replaced that again & it has not returned since & I have a all new exhaust system from the turbo to the tailpipe.

 

[9!'clipseDOHC]

i have personally fixed boost leaks at the fuel injector seals, throttle body shaft seals, throttle body gasket, j-pipe, nipple on j-pipe, BOV flange, and boost gauge source. I currently have a boost leak inside the turbo, the compressor o-ring. Its been ordered. Originally I would boost 12 psi. BLT from the throttle body would hold 0 and from the turbo inlet 0. Now it boosts 14 and holds 20 from the throttle body and 9 from the turbo inlet. BLTs need to done often, its not a one time thing.

 

[WeaselHack]

TB shaft seals and ### injector o-rings

 

[LiquidX]

Couplers, tb shaft seals, bad vacuum lines, AFPR screw, injector o rings, BOV, bad PCV, missing check valve for brabe booster (changed line without new valve).

All of them you just replace the bad part. Coupler you re tighten or re adjust how it sits and with the BOV my instance called for a new diaphragm and a crap ton of RTV to make it stop leaking. That barely worked well as it still leaked a bit.

A small leak can cause big problems.

 

[xezerax]

Throttlebody shaft seals were a big one for me, replaced them and holds much better. Now i just have to replace the intake manifold gasket. Other places were the injector seals, bliss screw o-ring, bov gasket, compressor housing on turbo( I have a pte5557 and there is only one bolt holding the wastgate actuator to the comp cover, it mustve loosened up after a couple thousand miles), and my gm maf leaks a little bit.

 

[razrman8]

Throttle body shaft seals they tend to dry out after 15+ years... . Some how managed a long tome ago to blow out a Intake manifold gasket once... Everyone should do a Boost leak test occasionally especially if they have noticed a loss of power or their boost drops off from normal...

How much of a difference with you TB shaft seals

Throttlebody shaft seals were a big one for me, replaced them and holds much better. Now i just have to replace the intake manifold gasket. Other places were the injector seals, bliss screw o-ring, bov gasket, compressor housing on turbo( I have a pte5557 and there is only one bolt holding the wastgate actuator to the comp cover, it mustve loosened up after a couple thousand miles), and my gm maf leaks a little bit.

Ahh the TB shaft seals.. how bad were tthey

 

[TSIfreek]

mostly at the throttle body.
Get one of this guys TBs with the uber seal upgrade.
Throttlebodys.Com

 

[Ghost1984]

Most of mine have been the vacuum lines themselves. I either didn't zip tie them all off, or the lines were just old and had a crack in them. So this winter I plan on going through and replacing the vacuum lines with new lines with zip ties

 

[rstchris]

I have seen a case where the coupler had a cut on the inside so air went through where the threads reinforce it. Basicly leaking from between the layers. My buddy 2gfoley replaced the stock bov with a greddy and went from 12psi to 24psi. until then he had no idea the wastegate line was f****d.

 

[Tyeler18]

It's always the TB shaft seals for me. Had a 91 TB on my 90 when I bought it and it couldn't hold any pressure at all. Threw in the old 90 TB and it would hold 2-3psi for maybe 5 seconds. Decided to just go with a NT TB instead.

 

[MY1GDSM]

mostly at the throttle body.
Get one of this guys TBs with the uber seal upgrade.
Throttlebodys.Com

Or you could save over $50 and Rebuild it yourself with this Rebuild Kit

How much of a difference with you TB shaft seals

Honestly I couldn't say, I did to many things at the same time when I rebuilt the TB... .

 

[stevemonroe]

Or you could save over $100 and Rebuild it yourself with this Rebuild Kit

Don't know where you got "save over $100."
I charge $115 including return shipping for a rebuild and when you get your TB back it will be cleaned, beadblasted, sensors tested, the TPS adusted etc.

 

[MY1GDSM]

Fixed... . The majoraty of DSM owners are cheap, Just throwing it out their... .
Don't take it personal not putting down your work or something... .I Was just saying it could be done yourself for cheaper For The DIY type... .

 

[BigBeans]

I made about 350whp with my intercooler in this condition

Fixing that leak made a difference,

 

[stevemonroe]

Fixed... . The majoraty of DSM owners are cheap, Just throwing it out their... .
Don't take it personal not putting down your work or something... .I Was just saying it could be done yourself for cheaper For The DIY type... .

No problem MY1GDSM! Many DIY'ers are capable of doing these rebuilds too. I only ask there be a level playing field to offer my service so thanks for correcting your post.

 

[razrman8]

No problem MY1GDSM! Many DIY'ers are capable of doing these rebuilds too. I only ask there be a level playing field to offer my service so thanks for correcting your post.

My dad called you this morning about buying a tb from you. Think we'll probably end up doing so.

 

[stevemonroe]

My dad called you this morning about buying a tb from you. Think we'll probably end up doing so.

Yes it's going to be at the post office in about 15 minutes. Thank you and your Dad!
Steve

 

[Slow91Laser]

As stupid as it sounds im having a really bad leak coming from the tps/tb screw and j-pipe as well.....

 

[9!'clipseDOHC]

As stupid as it sounds im having a really bad leak coming from the tps/tb screw and j-pipe as well.....

Are you referring to the BISS screw? Those don't sound stupid at all, they are very common spots for leaks.

 

[razrman8]

Yes, like 9! says, those are very common. I just fixed my leaks there yesterday. Swapped a new TB in . New seals, BISS, etc..

 

[9!'clipseDOHC]

Yes, like 9! says, those are very common. I just fixed my leaks there yesterday. Swapped a new TB in . New seals, BISS, etc..

Very good! Old, dirty throttle bodies are the source of a lot of annoying problems with these cars. I'm sure this nice fresh one will help you enjoy your DSM a lot more.