Front main bearing seal leak?

TEHOFF1870

MEMBER
2015 JEEP GRAND CHEROKEE
3.6L
6 CYL
4WD
AUTOMATIC
73,000 MILES

I’ve discovered what I believe to be a slow leak from the front crankshaft main bearing seal. My belief is based on seeing oil gunk collected on the front passenger side of the engine and also directly below the crank shaft location. Even spattered on the alternator. If I’m correct, it must be a very slow leak because the engine doesn’t use oil and there’s no spots on the garage floor. My question is that if I only drive the Jeep about 4,000 miles a year and plan to sell the vehicle in 18 months, is it worth the expense of getting it fixed or can I just manage it by watching the oil level? Am I in any danger of the vehicle just suddenly failing?

Thursday, December 4th, 2025 AT 8:31 AM

1 Reply

STEVE W.

MECHANIC
15,231 POSTS

That is most likely not the seal leaking but the oil cooler that is buried under the intake manifold. They have been a known issue since pretty much day one on the 3.6. A way to tell is simple, remove the engine cover and use a flashlight to look in the valley under the intake. If it's leaking the oil can pool up there and can get over an inch deep before you notice it getting out. I've seen it leak in the front and rear of the engine. The repair is to remove the upper and lower intakes and replace the cooler O-Rings. There are literally hundreds of videos on the replacement of the cooler. This is just one of them
https://www.youtube.com/watch?v=IPMoe875Ghw
Now if you really feel it is the front main seal, It is very easy to change it out. You remove the accessory belt. Then use a puller tool to remove the crankshaft damper then you use the seal remover (or the older trick is to use a couple sheet metal screws driven into the seal) and remove the old seal. Wipe up the area the seal goes into, then start the seal and gently tap it into place in the engine block. Then you apply some oil to the seal lip and slide the crankshaft damper back into place and use the installer or the retainer bolt to put it back into place and re-install the belt. Takes about an hour to do. Then change the oil just in case you knocked anything into the engine while cleaning the seals seat.

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