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I'm going to try the TTC mod to see if I can narrow down the possibilities before I take it back to Twins Turbo for a full diagnostic. (Money isn't exactly flying out of my ass these days.) Please let me know if you have any other suggestions.


Background:

Finally got a little time to look into this today. I took it down to Twins Turbo (Signal Hill, CA) and had them check it out. The car hesitates between 4-4.5K rpms and the max it will boost is 7 lbs. It is more likely to be a hose, valve, etc. problem than the turbo. There are no strange noises, smoke, etc. However, the turbo is still a possibility.
 

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Discussion Starter #2
already suggested

Saw some replies to my old post on this:

Steve, thanks for the TTC advice.
Mike, I will definitely look into replacing the IC hose clamps.
 
Z

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leak test is very simple to do.
take those garden plastic beg and fold it over 4 times. take off your air intake tube and use hose clamp to tighen the beg over the intake entrance.
than take one hose off of the intake manifold, start pushing air into the vacuum hose and have a friend start spraying soupy water on all vacuum hoses/IC tubes to look for air bubble(leak) or if there is a big leak you will be able to hear it whistle.
I did my test and found leak at HKS BOV screw, EGR block off plate.
BTW, 30-50psi of air pressure is enough.
 

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STREET STOMPING JEDI
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I have also tried this method. I found a few boost leaks but it did nto fix my low boost issue. 15 psi max. However I strongly non recommend this method. I killed my pressure switch for my avc-r this way adn you can also blow your head gasket, your rear main seal, your turbo seals adn alot of other things doing this. So far I think I have been fortuante not to have trashed much else but eventually I did blow the oil cap right off the motor from too much psi! So be careful as hell if doing this.

Ben...
 
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Obiwan said:
I have also tried this method. I found a few boost leaks but it did nto fix my low boost issue. 15 psi max. However I strongly non recommend this method. I killed my pressure switch for my avc-r this way adn you can also blow your head gasket, your rear main seal, your turbo seals adn alot of other things doing this. So far I think I have been fortuante not to have trashed much else but eventually I did blow the oil cap right off the motor from too much psi! So be careful as hell if doing this.

Ben...
like I said, 30 is plenty to find boost leak.
 
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About blowing your head gasket when doing this . . . can a compression test tell if you did blow your head gasket? What are the rear main seals?

I did this and I think I put to much PSI in! Air started leaking out from my oil cap hard core! What do you think I did to my car? I also have puffs of smoke shoot out my exhaust when I switch gears after being under WOT! Did my stupid mistake probably cause this as well?
 
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doctor7,

I am experiencing similar problems, I've posted twice this past week, and have some info on the other posts.. search for TTC question, and sporadic boost.. hope some of the info helps...
 
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when my friend did pressure test his oil cap leaked air also. whereas my TRD oil cap didnt leak at all. I think the spring inside the oil cap may be the reason, TRD does feel firm.
when you blow your head gasket, trust me, you will know.
our head gasket is not that easily damaged.
puff of smoke coming out exhaust can either be running rich which unburnt fuel comes out, or could be oil leaking out from your turbo seal. its quite normal...unless you are talking about ALOT of smoke?
 

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Guys, unless you have serious excessive blowby (ie horrible compression) there should be no pressure in the crankcase (oil cap, dipstick, etc) during this test.... You are capping off the hose running from the intake to the crankcase right???
 
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I did mine without the hose connected to the crankcase breather because I have a breather filter and a oilcatch tied to the breather! Therefore I should of had no pressure build up inside there but even after doing more tests I get air creeping out of my crank case filter and I do not know why or how???

Like I said the first time I did the test I was not familiar with my airtank and was trying to listen and turn slowly to let small amounts of air out but all the sudden a rush of air went out and my oil cap almost blew off and it probably would of if my friend did not keep it down!

I am wondering if I screwed it up when this happened or if I could of broke a turbo seal as well because I do get oil in my BOV and I also get that puff of smoke (sometimes the puff is huge) after shifting under high boost!

I think that the crankcase problem and my smoke puff problem are unrelated except for that both problems may of risen from the same stupid mistake! I think the BOV oil problem (which, yes is also in my damn intercooler pipes) and the smoke puff problems are related!

I am not trying to get a diagnosis for my smoke puffs I know where I am eventually heading to but my turbos are still pulling hard and the smoke puffs are not unbearable yet but I would like to know how to fix my crankcase problem as well as find out what caused it!

QUESTION: IF my crankcase leaked during the pressure test, will it be a source for a boost leak under WOT???

Thanks and sorry for the long post!
 

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chester, I would say that yes it would leak under WOT, Try capping the other crankcase breather hose, the one with the PCV attached. If that stops the leak then its probably just a bad PCV valve, a $2 part.
 

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doctor7,

Do you happen to have contact info for the Twins Turbo shop?

BTW, the email address that you submitted on this forum seems to have gone bad...


TIA,

Jay :blue:
 

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doctor7,

Thanks for the link.

Unless I'm totally blind, their web site fails to list an address & phone #.
Is it there and I'm just missing it?

So, if you happen to have that...

Jay :cool:
 
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Grant,
My compression test results were sound! 151, 154, 150, 149, 153, 150.
 
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supra_10 said:
doctor7,

Thanks for the link.

Unless I'm totally blind, their web site fails to list an address & phone #.
Is it there and I'm just missing it?

So, if you happen to have that...

Jay :cool:
It's at the bottom of each page...
 

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blowjob said:


It's at the bottom of each page...
Hey blowjob,

Thanks much. Your post made me thinking... and sure enough, the resolution at which my desktop is setup to, the bottom of their page was cut off.
I switched to a high res and v'oulla? Magic!

Thanks again,

Jay
 
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So we should have a direct air path during a boost leak test to the atmosphere through the crank case breather on the turbo side (thats why we should cap it) but there should not be a direct air path from the breather to under the oil cap????

If above is true then how come the breather does not act as a boost leak driving under WOT?
 
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