High oil leak

[Squirrel7487]

My son has a 2000 Ranger, V-6, 4.0L 4wd. It is leaking oil & when I took it to the dealership on Monday they said it was the Rear Main Seal & Oil Pan that are leaking. Wanting a second opinion I took it to an independent shop with a outstanding reputation this morning. They said it wasn't the rear main and pan. They said that it was coming from somewhere high up on the backside of the engine. Above where the intake manifold bolts to the block, but couldn't see the actual leak due to the way the engine is mounted. The plenum is in the way. My question is this - what is your best guess as to what could be leaking oil high up on the backside of the engine? I don't know a great amount about auto mechanics, but I am not dumb either. I just don't know the different parts that may be back there that have to do with the oil system.

 

[TxGasRacer]

Valve cover gaskets,or it could be your gasket end seals on your lower intake manifold they are at either end of your intake manifold where the intake manifold meets your engine block Front and Rear. It is going to be one or the other since it is NOT your rear main seal or your oil pan geaskets.

 

[Squirrel7487]

Thank you. The shop boss said they will take the plenum off and then should be able to see what is leaking. I am really hoping that it won't be too expensive to fix whatever it is they find.

 

[The_Epsicle]

Valve cover gaskets,or it could be your gasket end seals on your lower intake manifold they are at either end of your intake manifold where the intake manifold meets your engine block Front and Rear. It is going to be one or the other since it is NOT your rear main seal or your oil pan geaskets.

+1 I had the exact same thing going on with my Ranger, from the bottom though it sure did look like an oil pan gasket leak.

 

[chewy012]

Just did my oil, checked out my oil leak again.

I think my leaking rear main just turned into a leaking valve cover.

Thank God that's much easier to fix

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[chewy012]

Also, make sure you tighten your oil filter adequately. Turns out mine worked loose haha. That should solve one of them leaks.... unless I bound the gasket.... haha

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[HER2702]

Also, make sure you tighten your oil filter adequately. Turns out mine worked loose haha. That should solve one of them leaks.... unless I bound the gasket.... haha

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Just don't over tighten it. There's not much worse than having to get a hammer and chisel to remove an oil filter because someone used a wrench to tighten it as tight as they could. Almost all filters these days will have instructions actually printed on the filter. If not, a good rule of thumb is 3/4 to 1 turn after the gasket contacts the block.

A little trick I've found works great is to take a small dab of grease (after all, you're greasing the steering and driveline at every oil change. Aren't you?....) Rub the grease around the the face of the gasket on the filter before you install it. Next oil change the filter comes off without a fight!

And DON'T FORGET to make sure that the old gasket doesn't stick to the block!! Double gasketing will let lead to catastrophic leak that will smoke an engine!

 

[HER2702]

My son has a 2000 Ranger, V-6, 4.0L 4wd. It is leaking oil & when I took it to the dealership on Monday they said it was the Rear Main Seal & Oil Pan that are leaking. Wanting a second opinion I took it to an independent shop with a outstanding reputation this morning. They said it wasn't the rear main and pan. They said that it was coming from somewhere high up on the backside of the engine. Above where the intake manifold bolts to the block, but couldn't see the actual leak due to the way the engine is mounted. The plenum is in the way. My question is this - what is your best guess as to what could be leaking oil high up on the backside of the engine? I don't know a great amount about auto mechanics, but I am not dumb either. I just don't know the different parts that may be back there that have to do with the oil system.

I've had the same problem with my 94 4.0. Ford did away with the gasket under the rear rail of the intake manifold in favor of RTV sealer. Well...... over time the sealer deteriorates and oil runs down the back of the block. It's not a difficult job. The hardest part is snaking the plenum back in place and setting it without disturbing the RTV you laid on the block rail. Unless you dismantle everything above the level of the rail it's like a Chinese jig saw puzzle. And you can't see the plenum/rail to tell whether you were successful or not. The rear rail "gasket" is like the pot of gold at the end of the rainbow. You simply can't get one. Not even the aftermarket gasket manufacturers like FelPro, ROL, etc make them anymore.
Oh, and a tip on really reinstalling the upper plenum. Use a SMALL drop of BLUE thread locker on the studs that hold the upper plenum. The nuts tend to vibrate loose over time causing a vacuum leak. Be sure to use the blue (removable) thread locker and not the red (permanent) kind.

Best of luck to you with this.