HELP! my boost shut off.
03-20-2003, 04:13 PM
#1
Drifting
Thread Starter
HELP! my boost shut off.
I took it up to about 5000rpm in second and then she hesitated and the boost dropped to atm pressure. I thought it might be overboost protection, but shutting the car off didn't help. There is now a hissing noise coming from the front right area of the engine bay that dissapears when I blip the throttle. I'm guessing I blew a vacuum line to the waste gate or something equally simple. Now it just drives like a n/a car... no boost at all.
Thanks for any help you can offer.
Thanks for any help you can offer.
03-20-2003, 06:21 PM
#2
Rennlist Member
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I think you blew a line off the intake manifold. Which probably lets all your boost out when the turbo is running. There are several lines coming of the intake at various points. Check them all for cracks and splits. Make sure you check the wastegate signal line coming of the intercooler exit pipe to the cycling valve.
03-20-2003, 07:00 PM
#3
talking of hissing noises from the right front...is there usually a slight hissing/whooshing noise at idle from air flowing through the AFM etc? 'cos mine makes a bit of noise but it seems to drive ok still.
03-21-2003, 04:49 AM
#4
Racer
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my wastegate fell off on the freeway last week (hung on by the purocil, thankfully) - since the 951 has much lower compression than the n/a, with no boost, these cars are super slow!
03-21-2003, 06:01 AM
#5
Race Director
"my wastegate fell off on the freeway last week"
Don't you just hate it when that happens!
Could also be the rubber connections that hold your intercooler pipes that blew from the pressure. Start at your air-cleaner and take it apart and check each and every single connection in your intake plumbing...
Don't you just hate it when that happens!
Could also be the rubber connections that hold your intercooler pipes that blew from the pressure. Start at your air-cleaner and take it apart and check each and every single connection in your intake plumbing...
03-21-2003, 06:45 AM
#6
Racer
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its the second time the wastegate fell off too... I lowered my car to go racing, liked the way it looked and didn't raise it after wards, didn't quite clear a speedbump, bent my test pipe, stressed bolts holding wastegate, it falls off... I put it back on, couldn't get SAE (ick!) bolts the right length in time, didn't care, put on one long one, one short one, 2 months later it falls off again. Oh well...
03-21-2003, 11:38 AM
#7
Drifting
Thread Starter
I pulled the intercooler pipes and J-pipe off. The turbo spins nicely and none of the connections were obviously blown off the high pressure tubes. Mouth to mouth with the inake manifold and that hose that comes off right before the throtttle plate didn't reveal any major leaks. My exhaust sounds like the wastegate is open all the time too... just a little more raspy than normal.
Which hoses should be checked that would force the wastegate to stay open?
Justin
Which hoses should be checked that would force the wastegate to stay open?
Justin
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03-21-2003, 11:45 AM
#8
Drifting
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by JustinL:
<strong>Mouth to mouth with the inake manifold...
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Wow, you could do that?
<strong>Mouth to mouth with the inake manifold...
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Wow, you could do that?
03-21-2003, 11:51 AM
#9
Three Wheelin'
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Danno's right, check for cracks on the 2 rubber hoses that hold the pipes to the intercooler. The one on the hot side (passenger side) kept ripping on me until I switched to a silicone hose. I couldn't even see the rip, it was on the bottom. Couldn't see it till I took it off and pushed the hose a bit, at that point the crack smiled at me 
.
.
03-21-2003, 12:45 PM
#10
Drifting
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Last summer when pulling away from a stop light all of a sudden no boost and weird droneing noise and hesitation. When I got home and turned off the car it sounded like my exhaust was loose and there was a distinct rattle. The hoses were all fine so I pullled the wastegate off. the wastegate valve unscrewed it self and made its way 2/3 of the way down into the catylitic converter. I had to snake it out with a coat hanger. Fortunately it did not make its way up to the turbo and kiss the compressor turbine on the hot side. I gues I should have put some loctite on the valve threads when i shimmed the wastegate.
03-21-2003, 06:23 PM
#11
Drifting
Thread Starter
It looks like I have to replace the intake manifold gaskets in addition to tracking down this mysterious lack of boost. My mechanic suggested that while I'm underthere I should replace all the hoses, so I was wondering where I might be able to get a good price on them. Are there any aftermarket hoses that might be higher quality? Should I do all the vacuum lines as well?