I think I found my boost leak....

[MyBeatGSX]

I was looking around the engine to try to find another vacuum nipple on the intake manifold, then I noticed that the #4 (or is it #1? the passenger side one) injector has wet spots on either side of it in the recessed areas of the head. Could this be a boost leak? Maybe fuel being blown out through a bad o ring? Or do I have bigger problems? I don't see anywhere else the wetness could come from, there's nothing oil or coolant related in that area that I can see and none of the fuel system appears to be leaking....

 

[bigblock]

I can't tell you were your leak is but I can tell you were I found mine
1) fuel injector seals(one ones you were talking about)the cheapest place i found them was at Advance Auto parts ask for injector o-rings for a Camry or corolla and look at the picture before you order them they will have one extra part
2) intake gasket
3) throttle body shaft seals
4) PVC valve hose
5) throttle body gaskets (3 times)


have you built a boost leak detector tool yet I have 3 One in glove box one in tool box and one at the house you will definitely need one

 

[oldman]

have you built a boost leak detector tool yet I have 3 One in glove box one in tool box and one at the house you will definitely need one

I have four, one for my old 16g (2"), TB elbow (2.5"), New turbo (3") and tailpipe (4").

I was looking around the engine to try to find another vacuum nipple on the intake manifold, then I noticed that the #4 (or is it #1? the passenger side one) injector has wet spots on either side of it in the recessed areas of the head. Could this be a boost leak? Maybe fuel being blown out through a bad o ring? Or do I have bigger problems? I don't see anywhere else the wetness could come from, there's nothing oil or coolant related in that area that I can see and none of the fuel system appears to be leaking....

Either raw fuel is leaking down from the upper injector o-ring or air/fuel mixture is leaking back out of the lower injector insulator.

 

[MyBeatGSX]

^That's what I was figuring. Actually I haven't done a real boost leak test, I have no reason to believe the car has a boost leak, it was just something someone suggested because they thought my power numbers were kind of low. I just happened to noice the wetness around that injector while looking around under the hood and assumed that if its shooting the a/f mix back out its definately a boost leak. I think I'm gona put off replacing anything until I get the new injectors hopefully in a few weeks.

New injectors should have all new o rings already installed correct?

 

[oldman]

Actually I haven't done a real boost leak test, I have no reason to believe the car has a boost leak,

Let me guess, because you hold boost just fine right? Do a leak test anyway, you might be shocked at the results.

New injectors should have all new o rings already installed correct?

They should but not the lower insulators.

 

[MyBeatGSX]

No because it runs fine and yes it does hold boost, in fact its got a bad creap problem... and trust me, I believe you. That's why I'm scared to do the test because I don't really want to see the results.

But I was thinking about something, forgive me if I'm stating the obvious...

If the turbo is holding the set boost with a med-large sized leak, isn't that seriously overspeeding the turbo? Kinda like the turbo is trying to make that boost for an engine that's twice the size it actually is. How many people have blown compressor wheels from boost leaks?

 

[oldman]

If the turbo is holding the set boost with a med-large sized leak, isn't that seriously overspeeding the turbo? Kinda like the turbo is trying to make that boost for an engine that's twice the size it actually is.

You are exactly right. Besides maybe oil feed/return issues, boost leak is probably the number one turbo killer out there.

How many people have blown compressor wheels from boost leaks?

Do a search under "oldman" and start counting.

 

[negativezero27]

im not good with abbreviations but was does pvc mean? where is the pvc valve hose located at on the car?

yeah im a n00b

 

[oldman]

PCV = Positive Crankcase Ventilation

Looking at the car from the front, PCV valve is attached to the upper left corner of the VC (Valve Cover/engine cover), a hose should route the valve back to the IM (Intake Manifold). n00b=newbie aka (also known as) USE THE SEARCH BOTTON.

 

[Flip_4G63]

Correct me if i'm wrong. Don't you control boost with the T fitting from the compressor housing and the waist gate leading to your BCS.. If i am correct which i think i am if you had a boost leak from your TB o ring being worn or any where after the turbo you would not be making more boost to compensate for that boost being lost.

 

[oldman]

Correct me if i'm wrong. Don't you control boost with the T fitting from the compressor housing and the waist gate leading to your BCS.. If i am correct which i think i am if you had a boost leak from your TB o ring being worn or any where after the turbo you would not be making more boost to compensate for that boost being lost.

You're kinda right. First, the original poster has a mbc, probably tapped to the BOV. Tapping from the compressor housing in a case of bad boost leak will HELP prevent overspinning the turbo but not in the way you think it will, the key word there being "help" not cure. Let's say that you're losing 7psi worth of air at the IM, this doesn't mean your pressure at the compressor is 7psi greater than the IM, the ratio is not 1:1. I'm guessing, along with pressure drop from IC, about 3psi but only for a split second delay. Sometime though, that split second delay is what stands between you and a blown turbo.

 

[negativezero27]

PCV = Positive Crankcase Ventilation

Looking at the car from the front, PCV valve is attached to the upper left corner of the VC (Valve Cover/engine cover), a hose should route the valve back to the IM (Intake Manifold). n00b=newbie aka (also known as) USE THE SEARCH BOTTON.

thankz yo

 

[oldman]

thankz yo

You're welcome.

 

[negativezero27]

hey oldman it seems that you are "wise" when it comes to dsm, so do you mind if i ask you a question?

 

[Flip_4G63]

I get what you are saying there. Say you had a major boost leak loosing 5-6PSI that does not mean that your turbo is now pumping out almost 20 PSI though correct.

 

[oldman]

so do you mind if i ask you a question?

They don't take the thread jacking kind too kindly around here... Create your own thread and link me to it.

Unless it's related to this topic.

 

[oldman]

I get what you are saying there. Say you had a major boost leak loosing 5-6PSI that does not mean that your turbo is now pumping out almost 20 PSI though correct.

Too many variables, temperature, boost setting, rpm, load......etc. Best to just perform a leak test regularly and always pay attention to your car for any sudden changes.

 

[MyBeatGSX]

Ok so to prevent myself ventalating (sp?) the turbo housing.... Could a large leak (large enough to be dangerous) be noticed by boost gauge behavior? i.e. boost dropping off, or something like that. It seems if I had any kind of significant leak then boost creep wouldn't be a problem. Seems like it would even out or something like that. If the compressor goes in choke is it audible like surge or does the sound change? Obviously that anything will be hard to hear over the exhaust at WOT but it could give me something to watch out for...

 

[oldman]

Why are you so afraid of performing a leak test? The quicker you can eliminate boost leaks, even if you can verify the system is leak free, the quicker you can move on to other possibilities. Not to mention you still have boost creep to deal with.