What are the Symptoms of Leaks Under Boost?

[Speed_Dreamin']

I'm assuming that a leak under boost could cause boost spike, I'm wondering if there are any other symptoms?

 

[meanchicken]

What type of leak?

Boost leak, vacuum leak, or exhaust leak?

 

[Speed_Dreamin']

Any of the above. Wouldn't a vacuum leak be a boost leak?

 

[turbo39151]

Symptom of a leak or cause of a leak? (ie: like a faulty WG actuator- causes boost spikes)

 

[meanchicken]

Any of the above. Wouldn't a vacuum leak be a boost leak?

Errrrrrr...I don't think so.....one sucks the other blows....:biggrin:

Now you can of course blow off vacuum lines while in boost....or loose boost through a vacuum leak.......but I would visualize a boost leak to ocurr in the Turbo to IC to intake plumbing and a vacuum leak in the vacuum lines...

A "Boost" leak in the turbo plumbing will cause you to loose your boost, and a leaky vacuum line could cause you to over boost....

An exhaust leak would cause you to boost sloooooower....

 

[Speed_Dreamin']

Reason I'm asking is that I am chasing down a massive boost spike condition, and can't hold more than ~ 19 psi. The more I turn up the boost, the greater the spike, and it always settles at around 19. I've tried 3 different manual boost controllers, replaced the waste gate actuator, ported the wastegate hole on my TA-49, turbo seems to be in good health, all IC clamps are tight with good silicone connectors. The only logical next cause to me is a that I'm leaking boost pressure.

I am wondering if there are any other symptoms that may indicate that this is the problem. My BLMs are around 128 at idle, idle is smooth, boost comes on quick. Regardless, I am in process of setting up a leak test. I'll post the results.

 

[meanchicken]

Reason I'm asking is that I am chasing down a massive boost spike condition, and can't hold more than ~ 19 psi. The more I turn up the boost, the greater the spike, and it always settles at around 19. I've tried 3 different manual boost controllers, replaced the waste gate actuator, ported the wastegate hole on my TA-49, turbo seems to be in good health, all IC clamps are tight with good silicone connectors. The only logical next cause to me is a that I'm leaking boost pressure.

I am wondering if there are any other symptoms that may indicate that this is the problem. My BLMs are around 128 at idle, idle is smooth, boost comes on quick. Regardless, I am in process of setting up a leak test. I'll post the results.

Maybe a leaky IC or IC plumbing....?
All vac hoses are fresh?
How about those plastic valves (there are 2 two port valves and one 3 port on the drivers side of the engine bay) that are in line to your EGR and Vapor cannister etc.....they can act like leaks if they are blown...
Leak test should reveal something.

 

[ThikStik]

I chased my tail for awhile with a rich wot and an inconsistant off idle manner. Turned out my intecooler had a small leak AND the egr valve was leaking in a weird way that ive never heard of, it leaked where pintle enters body of valve (visible under diaphragm). So it was leaking vacuum and boost. Intercooler had been leaking since new.
Has anyone else ever seen egr leak like this?

 

[ungrave]

Try pressurizing your intake track from the intercooler with a compresssed air tank with 20psi and a pipe cap rigged up to have a compressor valve attachment or a large bike innertube cut so it fits over the intercooler intake pipe. Listen for leaks.

Do you have a blow off valve installed?

 

[austinibew145]

Try pressurizing your intake track from the intercooler with a compresssed air tank with 20psi and a pipe cap rigged up to have a compressor valve attachment or a large bike innertube cut so it fits over the intercooler intake pipe. Listen for leaks.

Do you have a blow off valve installed?

I used a soup can and soapy water to find my leak works on intake and exhaust