Oil leak at Valve Cover or bad rear main seal?

[Razorbackfan]

So I took my Ford Ranger XLT to the transmission shop today because I thought I was leaking tranny fluid. They checked it out and told me that the leak is not tranny fluid, its actually an oil leak in the Valve Cover/Valley. Then they add it MAY BE the rear main seal. When you are under the truck and you put pressure on the place where the engine and tranny meet, you get dribbled on with the fluid leaking. Anyone have experience or thoughts on this one? Is it possible the oil is just running down and when I touch that area it dribbles out or do you think its actually the main seal? Its been a year long back and forth with leaks on this truck from coolant leaks to lights coming on and so much more, I am ready to be done with this nightmare and fix it once and for all.

 

[franklin2]

Believe it or not, unless it has very high miles, the rear main seals do not have a tendency to leak. Not sure what the record is on the valve covers, but the standard procedure is to get some brake clean and a mirror and good flashlight. Get setup where you can see all the different areas behind the engine as best you can. Then spray it all down with brake cleaner, that will dry it up. Run it some and then take the mirror and the light and see if you can find where it's coming from. If the top part of the engine is all nice and dry like when you cleaned it, then it indeed might be the rear main.

Finding oil leaks is not easy, even for the seasoned mechanics. So try not to get frustrated if you do not find it right away.

 

[Curious Hound]

I agree. Clean the engine as best you can. Then watch to see where the leak originates. If you don't clean first, you'll just be guessing, like looking for a water leak in the ocean.

 

[lil_Blue_Ford]

Only way to tell is to try to clean and search. My 4.0 green Ranger both myself and a mechanic friend was sure it was a rear main leak because it was doing pretty much exactly what you’re describing. When the transmission puked on it, I used the rear main leak as an excuse to justify doing the 5.0 swap. In process of that, I really needed a good 4.0 for another truck and I had pulled engine/trans as a unit so I figured I’d split them, handle the rear main leak and use the engine…

There was no rear main leak. It was dry as the proverbial popcorn fart in there. Valve covers were both leaking in one little spot in the back and making it look like a serious problem. I glued new Felpro gaskets on the valve covers with gasket shellac.

 

[SenorNoob]

IDK about the 3.0, but the 4.0 is famous for valve cover leaks.