Oil in airbox + high oil pressure
09-02-2019, 05:04 PM
#1
Rennlist Member
Thread Starter
Oil in airbox + high oil pressure
Car has 112K miles. Idles and runs strong.
Recently noticed that the oil pressure at 5 bars when warm and idling. Knowing that pressure should drop at least 1 bar when idling warm I checked the sending unit and wiring to make sure the ground was ok and determined all was good.
My mind went straight to bad compression. Did a leakdown test and all was good. No fuel in oil and oil level on dipstick is good.
While poking around for clues I noticed a light film of oil underneath the intake and near the AOS with no obvious source.
I figured I needed to remove the intake manifold for a better look. When I opened the airbox to remove it there was an oil stain on the filter and a light film of oil on the bottom of the box.
I took off the j boot and found a very light film of oil and none on the MAF, Throttle body clean also.
I am a novice on the PCV system on the 968 so I went to the WSM and PET.
From what I can tell it seems like the the most obvious would be the oil pressure relief valve.
Any input would be greatly appreciated
Recently noticed that the oil pressure at 5 bars when warm and idling. Knowing that pressure should drop at least 1 bar when idling warm I checked the sending unit and wiring to make sure the ground was ok and determined all was good.
My mind went straight to bad compression. Did a leakdown test and all was good. No fuel in oil and oil level on dipstick is good.
While poking around for clues I noticed a light film of oil underneath the intake and near the AOS with no obvious source.
I figured I needed to remove the intake manifold for a better look. When I opened the airbox to remove it there was an oil stain on the filter and a light film of oil on the bottom of the box.
I took off the j boot and found a very light film of oil and none on the MAF, Throttle body clean also.
I am a novice on the PCV system on the 968 so I went to the WSM and PET.
From what I can tell it seems like the the most obvious would be the oil pressure relief valve.
Any input would be greatly appreciated
09-02-2019, 06:23 PM
#2
vacuum leaks can allow too much airflow in the AOS and the oil doesn't 'separate' out. if you pull the intake, do change those seals. there is a small vacuum elbow, besides the oil sucking hose on the aos, that comes the vario version of the 3 liter that cannot handle the oil. its a fun one to weasel on the fitting so you might slip the elbow and hard line on before fitting the intake.
the rear of the upper balance shaft cover can be an oil and a vacuum leak. brake clean and rtv work fine as the o-ring set up is destine for failure from the starting gate. ideally they would have used something similar to the rear cam plugs.
the rear of the upper balance shaft cover can be an oil and a vacuum leak. brake clean and rtv work fine as the o-ring set up is destine for failure from the starting gate. ideally they would have used something similar to the rear cam plugs.
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spark1 (09-02-2019)
09-02-2019, 07:39 PM
#4
it can get nasty under the intake but it is out of sight and neglected. the purpose of the small line on the top of the AOS is baffling.
there are a few loom/hose clips for the deicing coolant hose and the crankcase vent if you can reach underneath. if you can undo the coolant line at the back of the head and the larger AOS line at the AOS, you shouldn't have to disturb the pinch clamps at the throttle.
there are two O-rings at the throttle/intake connection if you want to remove the intake and leave the throttle coolant lines connected. ecs has that tool for forty bucks and belmetric has the oektier clamps in all the sizes.
I think there are four of the elbows but I don't think 'buy more and save' comes into play.
there are a few loom/hose clips for the deicing coolant hose and the crankcase vent if you can reach underneath. if you can undo the coolant line at the back of the head and the larger AOS line at the AOS, you shouldn't have to disturb the pinch clamps at the throttle.
there are two O-rings at the throttle/intake connection if you want to remove the intake and leave the throttle coolant lines connected. ecs has that tool for forty bucks and belmetric has the oektier clamps in all the sizes.
I think there are four of the elbows but I don't think 'buy more and save' comes into play.
09-02-2019, 08:43 PM
#5
Rennlist Member
Thread Starter
it can get nasty under the intake but it is out of sight and neglected. the purpose of the small line on the top of the AOS is baffling.
there are a few loom/hose clips for the deicing coolant hose and the crankcase vent if you can reach underneath. if you can undo the coolant line at the back of the head and the larger AOS line at the AOS, you shouldn't have to disturb the pinch clamps at the throttle.
there are two O-rings at the throttle/intake connection if you want to remove the intake and leave the throttle coolant lines connected. ecs has that tool for forty bucks and belmetric has the oektier clamps in all the sizes.
I think there are four of the elbows but I don't think 'buy more and save' comes into play.
there are a few loom/hose clips for the deicing coolant hose and the crankcase vent if you can reach underneath. if you can undo the coolant line at the back of the head and the larger AOS line at the AOS, you shouldn't have to disturb the pinch clamps at the throttle.
there are two O-rings at the throttle/intake connection if you want to remove the intake and leave the throttle coolant lines connected. ecs has that tool for forty bucks and belmetric has the oektier clamps in all the sizes.
I think there are four of the elbows but I don't think 'buy more and save' comes into play.