sucking noise from dipstick well when I take off oil dipstick
03-02-2012, 02:04 PM
#1
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sucking noise from dipstick well when I take off oil dipstick The problem:
When I take off the oil dipstick while the car's running, there's going to be sucking noise coming from the dipstick well(crankcase?)
I searched about this topic and also tried to use google, every thread that I found suggesting that this is problem with the pcv system. I checked all the lines are plugged in tight and the pcv valve still good(I even changed the valve twice but no luck)
The car is 99 camaro with LQ9 block and 243 heads, if anything.
Any help guys?
When I take off the oil dipstick while the car's running, there's going to be sucking noise coming from the dipstick well(crankcase?)
I searched about this topic and also tried to use google, every thread that I found suggesting that this is problem with the pcv system. I checked all the lines are plugged in tight and the pcv valve still good(I even changed the valve twice but no luck)
The car is 99 camaro with LQ9 block and 243 heads, if anything.
Any help guys?
03-02-2012, 03:56 PM
#2
The PCV system will try to suck outside air down the dipstick tube when the stick is removed - because it's continually trying to suck the crankcase out. Disconnect the PCV line and see if the sucking noise goes away. If so, you're just hearing the PCV system working as designed.
03-02-2012, 04:56 PM
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here's some pic of how my pcv system setup
line that's coming into the intake manifold
line that's going to the tube on the rear valve cover on the passenger side
line that's going to the rear valve cover on the driver's side.
is there any more line i should be aware of?
i notice i dont have the line that's going from the throttle body to the front side valve cover on the passenger side, both of them are sealed, could that be the problem?
with my car having 243 heads and LQ9 block wondering why the previous owner still use LS1 PCV design instead of swapping them to LS6 design....
it never happened before, i don't see why is it happening now. before i could take the dipstick while the car running and everything's fine no sucking noise. another thing is when i take off the oil dipstick the car still runs fine no bucking or anything..i'm confused now
line that's coming into the intake manifold
line that's going to the tube on the rear valve cover on the passenger side
line that's going to the rear valve cover on the driver's side.
is there any more line i should be aware of?
i notice i dont have the line that's going from the throttle body to the front side valve cover on the passenger side, both of them are sealed, could that be the problem?
with my car having 243 heads and LQ9 block wondering why the previous owner still use LS1 PCV design instead of swapping them to LS6 design....
The PCV system will try to suck outside air down the dipstick tube when the stick is removed - because it's continually trying to suck the crankcase out. Disconnect the PCV line and see if the sucking noise goes away. If so, you're just hearing the PCV system working as designed.
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03-06-2012, 08:25 PM
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I never had problem with the car running and take the stick off, there's never been a sucking noise from the dipstick well.
PatSS/00: I'll try that and see if it fixes my problem, the thing is I never had a line on there before and never had this problem, but its worth a try and the line shouldn't be expensive.
Anyone know where to find ls1 pcv diagram?
PatSS/00: I'll try that and see if it fixes my problem, the thing is I never had a line on there before and never had this problem, but its worth a try and the line shouldn't be expensive.
Anyone know where to find ls1 pcv diagram?
03-06-2012, 09:38 PM
#11
Well it's better to have too much vacuum than too much pressure (like, blowing out the dipstick). Also, the PCV valve opens different amounts depending on the rpm. From your pictures it looks like you have it hooked up correctly (except the fresh air hose).
03-06-2012, 10:21 PM
#12
I guess I missed the fact that the fresh air hose was missing. If the nipple on the RH valve cover where the fresh air hose goes is blocked off, then the PCV system is essentially sucking the crankcase down to a vacuum without any fresh air going into the crankcase (cheap version of a "crankcase evacuation system"). When the dipstick is removed, then the dipstick tube basically becomes the "fresh air line".
03-07-2012, 03:00 PM
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update: put the line that's going from the TB to the right hand valve cover and the sucking noise is gone. it fixes the problem, it's just weird that the line was blocked before but never had this problem but when i put new PCV line in it caused the problem. thanks guys for the info
03-07-2012, 03:53 PM
#14
update: put the line that's going from the TB to the right hand valve cover and the sucking noise is gone. it fixes the problem, it's just weird that the line was blocked before but never had this problem but when i put new PCV line in it caused the problem. thanks guys for the info
