258 oil leak

[jamesweed]

I just changed my oil pan seal and my main rear crank oil seal in my AMC 258 i6 / 4.2l . Now the thing is pissing oil about a drop every three seconds. I took off the bellhousing inspection plate and found a puddle of oil in the bottom of bellhousing, started up the motor and saw drops coming from rear U shaped area of oil pan, its impossible to tell if its coming from pan seal or rear main seal. I installed the expensive rubber molded gasket for the pan, and I didn't have any difficulties with the rear main seal. I sealed up edges of bearing cap with sealant and all, went very smooth till now. I cant fathom how this is happening. That being said, the valve cover leaks and has leaked for some time. Could it be possible that valve cover oil is getting inside the bellhousing somehow? I dont think so, but what do you all think? I hate the thought of dropping the SOB oil pan again.

 

[Tommy]

It could absolutely be coming from the leaky valve cover. The engine is slanted front to back and it drips right down into the bell housing. I had the same problem only worse on mine and stopping the valve cover leak solved it. I used "The Right Stuff" to form the gasket. Nothing else seemed to work. I did the same thing you did to and replaced the rear main seal and pan gasket first.

Tommy

 

[jamesweed]

It could absolutely be coming from the leaky valve cover. The engine is slanted front to back and it drips right down into the bell housing. I had the same problem only worse on mine and stopping the valve cover leak solved it. I used "The Right Stuff" to form the gasket. Nothing else seemed to work. I did the same thing you did to and replaced the rear main seal and pan gasket first.

Tommy

THX TOMMY,
I resealed the valve cover with the right stuff. Ran the engine for about 10 minutes, thought I had it solved, but then it started dripping again at the U shaped rear portion of the Oil pan, then slowed up a little bit. Im hoping its just residual oil laying up there somewhere. Does anyone know if those rear main seals burp a little bit when theyre new? Like theres a little break in time to "seal in" or did I screw something up?

 

[81laredo]

I looked at the rear main seals and at least the replacements are rubber. If you have a rubber seal then it really shouldn't have a "break in" period. Did you lube the seals when you first installed them? this would ensure that it doesn't start up with the seal dry.
Does your AMC 258 i6 / 4.2l have a breather? I have a PCV valve and the rear of the valve cover runs to the air filter.

 

[jamesweed]

I looked at the rear main seals and at least the replacements are rubber. If you have a rubber seal then it really shouldn't have a "break in" period. Did you lube the seals when you first installed them? this would ensure that it doesn't start up with the seal dry.
Does your AMC 258 i6 / 4.2l have a breather? I have a PCV valve and the rear of the valve cover runs to the air filter.

Yes I put soap on the back sides, engine oil on the crank sides, higher side of seal(lip?) forward, rtv on bearing cap mating surfaces. It was pretty easy, except for removing/installing the oil pan. cant see how it would be leaking. Im just hoping its residual. Going for a drive here soon to see how it does.

 

[jamesweed]

Ok I've verified that the valve cover is not leaking anymore, but Ive still got oil dripping out of the bell housing. Is there any way to tell if its the oil pan or rear main seal? Its just leaking out of the rear U shaped part of the pan, takes a few mins. to show up. Only leaks when engine runs. Is the oil level in the pan above the pan seal when engine is stopped? To reiterate Ive just changed both oil pan seal and rear main seal. Is there any other common leak that would come from inside bellhousing? I think this leak has been there for a long time since everything was covered with oil underneath before I took everything out and cleaned. Thanks! JAMES

 

[harborman]

Take some Gunk Foamy and get it all cleaned up, then check again. My CJ5 bell housing is just covered with oil inside and out!

 

[Kane]

Is your PCV valve working correctly? If the valve is not properly evacuating the gases and pressure from the crankcase usually the first place for a leak to happen is the rear main seal.

 

[jamesweed]

I ended up replacing the main seal again. The outer lip that sits down in the channel , opposite the crankshaft side, upper half of seal got damaged on the sharp opening of the engine block as I shoved it up and over. Word of advice: as you push the top half up and over the crank thru the channel, keep applying a little pressure on the still exposed portion of the seal, keep it hard up against crank as you feed it through. The further in it goes the more it wants to push away from the crank and grind on that sharp ledge in the engine block. Even oiled up it scraped just enough on that side to cause a leak.