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i recently installed a hks ss bov, i kept getting compressor surge so i kept tightening the spring up till it stopped, so the other day i was driving and was riding like shit so i say hmm maybe i have a boost leak cause id get full boost for a half a second then it would drop.... i was home doing the boost leak test wouldnt even pump up so i got the soapy water out and come to find out i have a crack in my valve cover that air is coming out of... so what im saying is, if i had the spring too tight on the bov would it "hold" air in longer then its supposed to and maybe have nowhere to go so it cracked my valve cover?? i have new ones on order but if this is the case, what else coiuld i have screwed up? thanks in advance
 

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Where was the crack out? People tend to crack them by overtightening them, and they'll crack in the corners. Not unheard of...
 
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mine was cracked in the corner right behind the cam gear, but i havent been back there for about 8 months when i did my seals again and i torqued them all to spec, now all of a sudden its cracked.....
 

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i cracked mine in corner by over tighten. was a hairline crack. got it welded and its been fine.
 

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a leaky valve cover can cause a boost drop?? when you say it hold full boost and then drop after that...how significant was the drop...for example, full boost of 1.3 and then half a second later its .50 bar. What was it....and good luck
 
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crazysupratt said:
a leaky valve cover can cause a boost drop?? when you say it hold full boost and then drop after that...how significant was the drop...for example, full boost of 1.3 and then half a second later its .50 bar. What was it....and good luck


yea pretty much just like that, i dunno if that was the reason or what, i just found the crack by doing the boost leak thing, pumping air in there and spraying some soapy water then i found it, im waiting to put on my new cover to see if anywhere else is leaking....
 

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inside the valve cover should not be much of a pressure at all even under boost... unless you are having a lot of blowby or your PCV valve where it connects to the intake manifold... which is basically a one way checkvalve to keep air from getting into the valve cover when under boost is not functioning correctly
 
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Why would you have boost inside the valve cover?
The only air under the valve cover is what's coming out of the crankcase, and should have nothing to do with boost unless you've got bad rings, in which case the cracked valve cover is the least of your worries.

On second thought, if the car's running like shit, maybe you should do a compression and leakdown test. Hurt cylinder(s) might cause you to lose boost.
 
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