Good afternoon. This is a very interesting issue I have found and tried to remedy. For context I have a 2004 TJ. 4.0 manual. Its mostly stock from factory. When I bought it, it was listed with an oil leak. I these past few weeks I have been ordering parts and fixing the known seals that leak. Rear main seal, oil pan gasket, and valve cover gasket with grommets. I have replaced all of these and still have a drip coming off the bell housing. I know its engine oil due to the smell and taste. lol. It will be dry for about 12 to 15 hours then a drop will appear. I am very confused because in my own words, there shouldnt be anywhere else oil could be leaking from. I made sure to install the rear main seal the correct way because I do not want to dive into that repair again. I even threw a new oil pan on it. Looking at where the oil dripping. It is on the back of the engine. maybe im checking too early and need to let whats left on the block settle down and drip down for a few weeks and shake that oil out from the bell housing. If you have any idea what It could be let me know so I can get this thing fixed.
Can’t find oil leak location
- Thread starter CasonsTJ01
- Start date
If it is not coming from the RMS, looking higher that would indicate a valve cover leak at the rear of the valve cover.
Edit: I see you mentioned replacing the Valve cover gasket. Did you ensure the bolts were torqued properly in the rear?
Edit: I see you mentioned replacing the Valve cover gasket. Did you ensure the bolts were torqued properly in the rear?
You could try that UV oil additive if you're unable to find the source
yes. the bolts we all snugged properly. the grommets are properly secured. and they bolts are in the correct locations.
yes. the grommets are brand new and the steel sleeves are installed.
i also took the time to clean the valve cover seal side with brake clean and remove the gunk one the top side with a plastic brush. both sides are clean and they mounted perfectly. was a quick install. both bolts on the rear of the head were snugged as far as they could go and then a 1/4 turn to snug them.
a rubber/steel one. soft blue rubber. i checked the valve cover this morning and there was no sign of a leak at all. so i have high confidence its not the valve cover
before replacing the gasket, the rear bolts were wet with oil and grime, the bolts have been dry since the new gasket and grommets were installed
I would doubt then it's your valve cover . my money would be on the rear main seal. I know you said you replaced it but many on here have done it 2, 3 or even 4 times to get it to stop. I'd use some gel or foaming engine degreaser on the back of the block and figure out for sure where it's coming from.
i will wait a few days to a week to make sure. the precious leak was a bit big. so there could be oil in the bell housing so it could be draining that old crud out. but if its the rms. ill just take it to a shop to fix it. i dont rlly have the time to fix it over a weekend. removing the thing is a pain. but ill report back when i find out the reason. thanks for the time and responses
JEEPSTEVENANAIMO
TJ Enthusiast
I had to use the Victor Reinz offset seal to cut my leak down.
The crankshaft gets grooved over time and the traditional seals become ineffective.
https://www.rockauto.com/en/moreinfo.php?pk=11472421&cc=1431777&pt=5604&jsn=998
What kind of oil are you running, the synthetics and the 4.0 rear main don't always play well together.
If Jerry were still here he’d say something about running 75W-90 Dino Juice to stop his RMS leak.
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