Oil Leak between Tranny and engine

[Teepee]

Hello and thank you in advance.
Trying to be brief and not seem rude.
There is oil gathered on the two bolts around where the transmission joins the engine.
the two bolts are to the rear of the vehicle from the Oil Drain plug in the pan.
Any help would be appreciated.
Tony
1997 Ford Truck Explorer 2WD 4.0L EFI SOHC 6cyl

 

[mikeg216]

bad rear main seal possibly

 

[Teepee]

Is there a way I can check if it is the seal?
Cheers
Tony

 

[Teepee]

I took a picture to show the leak.
I wiped the area and this was about 12 hours later

Thanks for looking
Tony

 

[SoNic67]

That's normal weeping after some 150k miles.
And yes, in that area, the only thing that can leak (motor oil) is the main rear seal (crankshaft). Replacing it requires separating of engine from transmission, so most of us live with it.
http://www.justanswer.com/ford/0mbc1-put-oil-pump-1993-ford-explorer.html

 

[2000StreetRod]

ATF or engine oil?

Try to determine if the leak is automatic transmission fluid (ATF) or engine oil. Either can leak from that location. Engine oil can leak from the rear main seal, the block to upper pan (reinforcement section) junction or the upper pan to lower pan junction. It is very difficult to determine the source with the transmission attached. The most common place is the rear main seal.

 

[Teepee]

Thank you for such quick responses.
Other than
1: changing the rear seal
2: accepting the small oil stain on the driveway
3: checking the oil more frequently
are there any other options
Thank you again
Tony

 

[JohnnyO]

Thank you for such quick responses.
Other than
1: changing the rear seal
2: accepting the small oil stain on the driveway
3: checking the oil more frequently
are there any other options
Thank you again
Tony

I'm not one for promoting miracle-in-a-bottle crap, but this stuff called Auto-RX does clean and condition seals. I've used it on a few older vehicles with some degree of success. For $25 a bottle it's worth a shot before you yank the tranny. .02.

www.auto-rx.com

 

[drdoom]

Check to see if it's running from above. I have oil at the same spot. I was thinking my rear main seal was leaking, but I found it running from above, the rear hydraulic tensioner.

 

[Teepee]

Thank you guys for your responses..
I will get outside in the morning to look for leaks from above..
I'll check in then.
Tony

 

[gmanpaint]

Check the valve cover gaskets as well. Look/feel on the back side of them by the firewall. Oil can run down the block and be seen where you have it collecting/dripping from.

I replaced my rear main seal when I had the trans out, but before I removed it, I swore the seal was bad, but in fact it was the valve cover gasket that had been bad.

 

[cmhaah06]

Teepee - My 91 ex has recently started leaking oil in the exact same spot. I am thinking its the rear main seal as well. I may try a genie in a bottle type fix for now, but need to replace soon. I hate leaking oil.

 

[gcpitts]

After having the rear main seal replaced, oil spots started showing up again on the driveway. The technician said that, because it has 140,000 miles that 'additional internal pressure' would cause leakage, even with the new seal. Souds fishy. Comments?

 

[crunchie_frog]

Hello and thank you in advance.
Trying to be brief and not seem rude.
There is oil gathered on the two bolts around where the transmission joins the engine.
the two bolts are to the rear of the vehicle from the Oil Drain plug in the pan.
Any help would be appreciated.
Tony
1997 Ford Truck Explorer 2WD 4.0L EFI SOHC 6cyl

If you are using a 5w20 weight or lower oil you could switch to 5w30 and this will slow the leak. Also, if you are not using a "high mileage" oil, you could switch to that. The "high mileage" oils have seal conditioners in them, which I really think it means they just soften and swell the seals. There are also seal conditioner additives, that will do the same. Ultimately though, you are just buying time. Others will object to using seal conditioner additives or maybe even to a "high mileage" oil but I use a "high mileage" oil and that has stopped my rear main leaks and I have not had any other problems, yet. But again, I am just buying time.

 

[rb142]

After having the rear main seal replaced, oil spots started showing up again on the driveway. The technician said that, because it has 140,000 miles that 'additional internal pressure' would cause leakage, even with the new seal. Souds fishy. Comments?

Three year old thread ... so let's address the new question.

A bad PCV system can cause a buildup of pressure enough to cause oil leakage at the rear main seal and various other locations. Check that your PCV valve is not stuck and the lines aren't plugged. That would be a cheap fix. Otherwise, if you had the rear seal replaced and it is still leaking, i'd say your mechanic screwed it up -- maybe damaged the seal during installation or something.

 

[metoymi]

1999 Explorer 5.0 2WD, 108,000+ miles. Purchased in May 2015. Runs great.

Lets continue thread with a new twist. I discovered an oil leak in my driveway and took the car to mechanic. After lifting on hoist, it was determined that the leak was occurring from the oil pan gasket. But the transmission had to be dropped in order to get to it. When work started, a leak from the rear main seal was also "thought" to be leaking. So the main seal was replaced with the oil pan gasket. After everything was put back together, I detected another leak and the main seal was again suspected. And it was replaced a second time. When I got the car back, after a couple of days driving I discovered yet another leak and it seemed to be in the same area as the rear main seal again. After lifting the car on the hoist again, the mechanic thinks that the rear main seal was a mis-diagnosis. He now thinks that the rear of the oil pan itself may be slightly warped and causing oil under pressure to leak onto the bell housing and dripping down from the area of the main seal. He wants to replace the oil pan with a used one. He was quoted $75.00 for a used oil pan.

Does that sound plausible to anyone? I don't hear of oil pans being replaced unless they are visually cracked. Do they actually warp over time?

 

[Andrea P]

1999 Explorer 5.0 2WD, 108,000+ miles. Purchased in May 2015. Runs great.

Lets continue thread with a new twist. I discovered an oil leak in my driveway and took the car to mechanic. After lifting on hoist, it was determined that the leak was occurring from the oil pan gasket. But the transmission had to be dropped in order to get to it. When work started, a leak from the rear main seal was also "thought" to be leaking. So the main seal was replaced with the oil pan gasket. After everything was put back together, I detected another leak and the main seal was again suspected. And it was replaced a second time. When I got the car back, after a couple of days driving I discovered yet another leak and it seemed to be in the same area as the rear main seal again. After lifting the car on the hoist again, the mechanic thinks that the rear main seal was a mis-diagnosis. He now thinks that the rear of the oil pan itself may be slightly warped and causing oil under pressure to leak onto the bell housing and dripping down from the area of the main seal. He wants to replace the oil pan with a used one. He was quoted $75.00 for a used oil pan.

Does that sound plausible to anyone? I don't hear of oil pans being replaced unless they are visually cracked. Do they actually warp over time?

What did you wind up doing? I have a 96 leaking oil, but I am not sure from where..

 

[koda2000]

The only time oil pans warp is from the retaining bolts being over tightened by ham-fisted mechanics, or from hitting something. Other sources of rear engine oil leaks can be from valve cover gasket leaks or intake manifold leaks. Leaks from either of these areas tend to look like rear main seal or oil pan leaks gravity being what it is.

 

[lobo411]

IMO the biggest question is not "from where?" but "how much?"

A few drops a day isn't worth tearing up the car over. In fact, in trying to fix a minor leak, one is more likely to create more problems.

 

[bigred4x4]

Mine still leaks a little even after replacing the seals (there is a tsb on this issue) but not enough for me to add any extra oil between changes. So...no big deal .