I thought I had a rear main seal leak... but maybe its the oil pressure sending unit?
07-13-2012, 04:44 PM
#1
TECH Enthusiast
Thread Starter
I thought I had a rear main seal leak... but maybe its the oil pressure sending unit? Ok, so... I'm trying to track down my oil leak and need serious help as it's going to destroy my brand new clutch. (clutch is already slipping).
I replaced my rear main seal when I did my engine swap, I also changed out the oil pressure sending unit... hell.. I changed out everything but the heads lol.
When I first got the car running I didn't notice the oil leak.. it might have been there but it must have been subtle and I was distracted with all the other things I was doing. When I first started the car up though at idle it gave me between 30 and 40 PSI, rarely would it go over 40 though even in high rpm situations. Within days however it's been idling at about 20 PSI oil pressure, and it gets to about 40PSI at 3000rpm also it has a leak which I attributed to the rear main seal, this leak only occurs when the car is completely off and is starting to make my clutch slip.. which makes me think it's leaking onto the flywheel which is throwing it everywhere, and that it pools up and drips down once the cars been off for a couple minutes. The oilpressure is on the low end, but the car ran fine otherwise ( except for mild clutch slip when cold ). So I made an appointment at a transmission shop for Monday, and he gave me a can of "gasket repair fluid" which he said I should poor into my oil and drive around with for the weekend as it'll reduce the leak a bit if it's not the rear main seal.
Fast forward 24 hours, oil leak is about half what it used to be and oil pressure now is steady at 40 PSI and up to 50 PSI under high RPM.
What could cause this? I've never heard of a rear main seal causing a drop in oil pressure?? Could I have accidentally not torqued down the Oil pressure sending unit enough? What else could it be??
Any ideas??
I replaced my rear main seal when I did my engine swap, I also changed out the oil pressure sending unit... hell.. I changed out everything but the heads lol.
When I first got the car running I didn't notice the oil leak.. it might have been there but it must have been subtle and I was distracted with all the other things I was doing. When I first started the car up though at idle it gave me between 30 and 40 PSI, rarely would it go over 40 though even in high rpm situations. Within days however it's been idling at about 20 PSI oil pressure, and it gets to about 40PSI at 3000rpm also it has a leak which I attributed to the rear main seal, this leak only occurs when the car is completely off and is starting to make my clutch slip.. which makes me think it's leaking onto the flywheel which is throwing it everywhere, and that it pools up and drips down once the cars been off for a couple minutes. The oilpressure is on the low end, but the car ran fine otherwise ( except for mild clutch slip when cold ). So I made an appointment at a transmission shop for Monday, and he gave me a can of "gasket repair fluid" which he said I should poor into my oil and drive around with for the weekend as it'll reduce the leak a bit if it's not the rear main seal.
Fast forward 24 hours, oil leak is about half what it used to be and oil pressure now is steady at 40 PSI and up to 50 PSI under high RPM.
What could cause this? I've never heard of a rear main seal causing a drop in oil pressure?? Could I have accidentally not torqued down the Oil pressure sending unit enough? What else could it be??
Any ideas??
07-20-2012, 02:21 AM
#2
Did you get this figured out?
The only way your going to get oil into the bellhousing is from the oil pan, rear cover or the rear main. Theres really no other way for it to get in there.
Its fairly common for the oil pan gasket to leak where it meets with the rear cover gasket (especially if you took it off to replace the rear main)... cant say ive ever seen it leak from the rear cover itself tho. None of those issues are going to cause oil pressure loss though.
You could be leaking from the valve covers or oil pressure sending unit, but those would just drip down the outside of the bellhousing. The oil pressure sending unit not being tight WOULD cause a low reading if it was leaking.
Hope that helps.
The only way your going to get oil into the bellhousing is from the oil pan, rear cover or the rear main. Theres really no other way for it to get in there.
Its fairly common for the oil pan gasket to leak where it meets with the rear cover gasket (especially if you took it off to replace the rear main)... cant say ive ever seen it leak from the rear cover itself tho. None of those issues are going to cause oil pressure loss though.
You could be leaking from the valve covers or oil pressure sending unit, but those would just drip down the outside of the bellhousing. The oil pressure sending unit not being tight WOULD cause a low reading if it was leaking.
Hope that helps.
07-20-2012, 07:05 PM
#4
TECH Fanatic
Get some flourescent dye and let it run. One of the best ways to pinpoint a leak. Try and get some carb spray or brake cleaner to wash that part of the engine down first so you can see it. Oh, and minimum spec for oil pressure is 6 psi hot. Now does you're factory gauge read true? That I doubt.
