[Z06] LS7 rear main seal or oil pan gasket leak?
#1
LS7 rear main seal or oil pan gasket leak?
I did a cam swap on my c6z at home and we unbolted the oil pan just enough to pry and pull the oil pump out. Finished up, car is up and running but been having an oil leak since then. I have washed everything with brake cleaner, cleaned it up, and narrowed down the leak from half the oil pan to the back towards the bell housing. Here are the results. My first guess is that I need a new oil pan gasket, but is it possible that I have damaged the rear main seal from the cam swap? I did run the car with no catch can for a few weeks before I got my wild kit from mighty mouse solutions.
Last edited by Z0HM6; 12-06-2018 at 12:37 PM.
#2
Former Vendor
Most likely that the original gasket did not seal up once you loosened the oil pan. With the leak starting right after you loosening the pan, hard to point towards the rear main seal. Sometimes the rubber on the old gaskets will not seal with being so old.
Grab a new pan gasket and install properly. If your in the the north east near us and dont want to tackle the job yourself give us a shout.
Grab a new pan gasket and install properly. If your in the the north east near us and dont want to tackle the job yourself give us a shout.
#3
Most likely that the original gasket did not seal up once you loosened the oil pan. With the leak starting right after you loosening the pan, hard to point towards the rear main seal. Sometimes the rubber on the old gaskets will not seal with being so old.
Grab a new pan gasket and install properly. If your in the the north east near us and dont want to tackle the job yourself give us a shout.
Grab a new pan gasket and install properly. If your in the the north east near us and dont want to tackle the job yourself give us a shout.
#4
Drifting
Where the rear cover and oil pan gasket meet up likely got disturbed when you pulled the pan down.
The following users liked this post:
Z0HM6 (12-10-2018)
#5
Instructor
If you put the oil pump in and it sits a little below edge of the block the oil pan will not seal, the oil pump has to be flush with the bottom of the block or no more than I think .004 above the block bottom surface. Also did you silicone the front corners of the pan front cover junction as per the manual or you could be leaking from the front corners and running down the pan. Changing the cam will have no impact on the rear seal at all, you would have to have removed the rear cover to affect the rear seal and with the engine in the car thats not going to happen.I just changed my cam and oil pump but I did not lower the pan , I used shim stock on the gasket between the pan and the pump but have not started the engine yet so dont know if that is totally successfull yet. But when I changed the pump it comes with plastic injected into to the bolt mounting holes which I think was done in a jig so that the pump lines up on the crank properly so I think it is hard to get the oil pump to low below the bottom of the block, the only other area that the oil could get out would be the front seal if it was damaged on re installing the front cover. Your most likely problem will be the pan gasket and I think you need to silicone the rear corners just like the front corners if you drop the pan down.
#6
Looking at your pics it shouldn’t be the rear main. It also wouldn’t have been affected by the cam swap unless you just had bad luck. However it is odd that there is an oil drip on the starter. There is also oil forward on the pan bolt but I don’t see it along the edge of the pan. Because I only have your pics to rely on there is a chance it’s from the back corner of the valve cover or pcv on the passenger side and trailing down. You start at the highest point you see oil. If it’s dry above the starter or pan then never mind it should be the pan gasket. As mentioned don’t forget sealant at the edges where the front and rear covers meet the block and pan or it will leak again.
The following users liked this post:
Z0HM6 (12-10-2018)
#8
https://www.corvetteforum.com/forums...uter-bolt.html
You may want to look into this.
You may want to look into this.
The following users liked this post:
Z0HM6 (12-10-2018)
#10
If you put the oil pump in and it sits a little below edge of the block the oil pan will not seal, the oil pump has to be flush with the bottom of the block or no more than I think .004 above the block bottom surface. Also did you silicone the front corners of the pan front cover junction as per the manual or you could be leaking from the front corners and running down the pan. Changing the cam will have no impact on the rear seal at all, you would have to have removed the rear cover to affect the rear seal and with the engine in the car thats not going to happen.I just changed my cam and oil pump but I did not lower the pan , I used shim stock on the gasket between the pan and the pump but have not started the engine yet so dont know if that is totally successfull yet. But when I changed the pump it comes with plastic injected into to the bolt mounting holes which I think was done in a jig so that the pump lines up on the crank properly so I think it is hard to get the oil pump to low below the bottom of the block, the only other area that the oil could get out would be the front seal if it was damaged on re installing the front cover. Your most likely problem will be the pan gasket and I think you need to silicone the rear corners just like the front corners if you drop the pan down.
#11
Looking at your pics it shouldn’t be the rear main. It also wouldn’t have been affected by the cam swap unless you just had bad luck. However it is odd that there is an oil drip on the starter. There is also oil forward on the pan bolt but I don’t see it along the edge of the pan. Because I only have your pics to rely on there is a chance it’s from the back corner of the valve cover or pcv on the passenger side and trailing down. You start at the highest point you see oil. If it’s dry above the starter or pan then never mind it should be the pan gasket. As mentioned don’t forget sealant at the edges where the front and rear covers meet the block and pan or it will leak again.
#12
Safety Car
I had a leak around the oil filter housing that ran down on the bottom of the bell housing like your picture. I checked the oil pan bolts, oil pan bolt and replaced the oil filter, but the leak was still there. I assumed the rear main seal went bad, but It turned out to be the high pressure oil cooler lines that leaked. Might be worth taking a closer look before doing an oil pan gasket change.
Last edited by Mike's LS3; 12-11-2018 at 02:35 PM.