Oil leak trickle near rear of oil pan

Tried to find related threads, just wondering leak source possibilities. 2000 Prerunner 5ZE. I have a slow oil trickle down from the rear of the oil pan looks like between the pan and the flywheel housing. When I leave it a few days before wiping, it settles around the drain plug with a drop but I know it's not coming from drain plug. Some places around the edges of the pan seem a bit moist from it too, not sure if it's gasket or from above. Valve covers are not leaking though, so is it possibly rear main seal or plenum? And can I take off the flywheel dust cover w/o draining anything to check tightness of hard-to-reach pan bolts? Anywhere else to look? Ok thanks!

 

My money is on rear cam seals. Just changed mine. Do you ever smell it getting on the exhaust? I did a small write-up on my adventure.

 

Thanks will check it out. I get the feeling it's not the pan gasket I think it's from above, and rear of the engine.

 

Been having a similar issue. I ended up deducing it was the oil pan gasket since I have replaced all seals from headgasket up within the last 20K miles... also have done the rear main seal already...

At any rate, I took off front differential last weekend and took off oil pan and did the new seal with the FIPG... but haven't driven the truck much since, since the weathers been so nice, been on my bike. We will see if it pops up again or if anything else sneaky back there is causing the issue. But mine could pretty much have been described exactly how you said it.. dry every where else.. but around the lip of the entire oil pan it seemed damp with oil... maybe be sure to degrease and check below the oil cooler?

 

It may be the rear main seal (aka crankshaft seal). It is located behind the flywheel/flex-plate (depending on manual vs auto tranny). It will leak down and usually show where the tranny meets the block (back of oil pan).

 

Well I started by completely degreasing and wiping off all of the excess oil leak and then cinched up all the oil pan bolts in a criss cross pattern, and found that some of them were alarmingly loose. Previous owner service maybe. It really did seem like the whole pan gasket area had been sweating. I also rubbed a bit of permatex around the perimeter just for good measure, it was all I could do for now. I checked what member GA-3RZFE said, and either because of the wind or some strange leak path, there wasn't any actual leak from the rear of the pan where the tranny mates up to the block, so fingers crossed for now. Hoping member Washington Ag and I have a little luck with this. I have to drive a lot in the next couple days so I will report back after checking underneath again. Thx

 

careful over-torquing those bolts. I believe the manual states the pan bolts are 10 or 12 ft lbs (that is on a 2.7L). Hopefully you found the problem!

 

The rear crankshaft seal is located on the back of the block (block is upside down in the picture). This is a 2.7L, so it may be different on a V6.



The seal is that brownish red circle in the cover. It pulls out and you press the next one in (i pressed it in by hand).

 

Reporting back, wow the area where it had been leaking is bone dry now after many days and miles. I got lucky I know, and would recommend checking this when anyone has a similar leak around the pan and rim, even when there's leak evidence in nearby places like mine had. This time it was the pan, and after carefully cinching up the bolts, there's no oil leaking of any kind anywhere. By the way, great pics of the rear seal, GA-3RZFE, clean looking motor. Only a matter of time before my next repair adventure......

 

Thanks OP. I'm proud of all the work I put into it.

 

Clean is not the word for that motor. It's.......Formula 1