Rear pan bolt still showing oil after gasket replaced
05-19-2018, 06:21 PM
#1
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Rear pan bolt still showing oil after gasket replaced
My pan was seeping on both sides, and early this year I noticed the rear pan bolt behind the oil filter close to the bellhousing seemed like it was leaking to the point of a drip forming on the bolt head & a drip forming from the oil filter overnight. I had cleaned the area and sat under the car as it ran and saw oil seep / bubbling from the bolt head so was pretty confident the actual pan bolt was the location of the leak.
Considering it was at a drip level, and the headers are right there, I had a shop replace my pan gasket. Got it home and checked it the next evening - there was still oil on that bolt / around the area. Cleaned it up and sat under it as it ran and it seemed like while the rest of the pan seemed clean / no seeping, that bolt still started seeping.
I don't see anything from above that location leaking down. The only other question mark I suppose would be if something is running down / in from the bellhousing side right behind there? Or does it seem like maybe that corner didn't get RTV'd properly? Can't really think of what else it might be but figured I'd check with people smarter than me.
Considering it was at a drip level, and the headers are right there, I had a shop replace my pan gasket. Got it home and checked it the next evening - there was still oil on that bolt / around the area. Cleaned it up and sat under it as it ran and it seemed like while the rest of the pan seemed clean / no seeping, that bolt still started seeping.
I don't see anything from above that location leaking down. The only other question mark I suppose would be if something is running down / in from the bellhousing side right behind there? Or does it seem like maybe that corner didn't get RTV'd properly? Can't really think of what else it might be but figured I'd check with people smarter than me.
05-19-2018, 06:24 PM
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Also, I'm pretty sure the oil down towards the bottom of the plastic plate in the pic was from me removing the oil thermostat in the pic today and replacing some recalled screws on that - some oil seeped down from the block off plate opening, or possibly from the bolt head dripping earlier and me not being able to clean it all up. (It was there when I started the car up to check for leaks)
05-19-2018, 07:35 PM
#3
Team Owner
Could be rear main seal.
05-19-2018, 09:04 PM
#4
Melting Slicks
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Oil
Does any one know if all the pan bolts are the same length ?
Last edited by 2008 Corvette; 05-19-2018 at 09:05 PM.
05-20-2018, 08:32 AM
#5
Team Owner
They are not.
05-20-2018, 09:54 AM
#6
Instructor
If its a shop you trust I’d take it back. When clients brought us a car with a oil leak we wouldn’t just replace a seal and hand over keys. We would clean the hell out of the area and run car on lift to determine seal that was bad, this can be hard and sometimes impossible. Then replace seal and test back on lift. We charged the client for the solution, not a part replacement. Not sure why they handed you back a leaking car unless it’s just a realllllly slow leak that doesn’t present itself easily. But like others have hinted oil leaks can be hard to pin down, always try hard to trace path. But sometimes that takes a good collection of mirrors and a lift.
05-20-2018, 11:23 AM
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Melting Slicks
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Oil Leak
If the pan bolts are different lengths is it possible that the bolt in that position is bottomed out and not sealing the pan gasket ?
05-21-2018, 10:34 AM
#8
Team Owner
No, as the length difference is huge, like 6" vs 1.5".
05-21-2018, 12:22 PM
#9
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If its a shop you trust I’d take it back. When clients brought us a car with a oil leak we wouldn’t just replace a seal and hand over keys. We would clean the hell out of the area and run car on lift to determine seal that was bad, this can be hard and sometimes impossible. Then replace seal and test back on lift. We charged the client for the solution, not a part replacement. Not sure why they handed you back a leaking car unless it’s just a realllllly slow leak that doesn’t present itself easily. But like others have hinted oil leaks can be hard to pin down, always try hard to trace path. But sometimes that takes a good collection of mirrors and a lift.
Yeah, I can see that. In the shop's defense I approached them asking for my oil pan gasket to be replaced, where I really should have had them diagnose the leak(s). I had observed oil bubbling out from underneath that pan bolt and had enough oil there that it would get near two drips (bolt, and filter) sitting overnight after running. Also the pan was seeping on both sides, so after re-torquing the bolts didn't help, figured I'd just have them do the pan.
They did mention it was 2 qts low, which I had just measured and topped off after the oil cooler install, and have only had a small handful of drives with the long winter this year. (I haven't really seen anything on the garage floor though, and I've been checking and cleaning pretty much between drives, so thought it was strange). Prolly would have been nice to know it was still seeping before it left the shop.
I guess I might pull the intake and check / hope it's the oil pressure sender - I pulled the driver's side cover but still can't quite see it, though what I can see below seems dry. Maybe let it run for longer and see if I notice anything leaking out the bottom of the bellhousing, though I never really have to this point. Dunno if I can get a q-tip or something in behind that bolt in the bellhousing to try to find oil.
Last edited by blizz81; 05-21-2018 at 12:26 PM.