oil leak onto exhaust manifold

[Levi B]

I have a '96 legacy with an ej22 and 5spd transmission. When I got the car it was leaking oil straight onto the exhaust manifold. It smelled bad but eventually it got to the point where I could see smoke coming out of the hood at stoplights. After some research I learned it would likely be the rear main seal. This, combined with some other factors, prompted me to pull my motor and replace the rear main seal (along with front seal, timing belt, water pump, clutch, valve cover gaskets, etc.)

If you are looking at the rear of the motor with the flywheel removed I also replaced the o-ring on the plate held in by 2 phillips head screws to the left (driver side) of the crankshaft, and I re-did the gasket (using silicone) on the plate that is larger, and to the right (pass. side) of the crankshaft. There is literally nothing behind the flywheel that could possibly be leaking right now.

Once the engine was re-installed, and I drove it around the block I noticed a burning smell. The same leak persists, even though I replaced everything that could have been leaking from the motor. I have looked for a long time to find the source of this leak and I still can't. Does anyone have suggestions as to what is leaking? I'm beyond frustrated trying to find this leak and I am hoping it is not from the motor.

[86bratman]

Usually replacing the rear main on these engines causes more problems than it fixes, the main source of the leak is the separator plate, the large one to the right of the crank. It should have been replaced with the updated metal plate and new screws from subaru, resealing the plastic one is a fruitless endeavor 99.8% of the time. If you didn't get the rear main seated exactly how the original was then you will either be leaking or blocking an oil passage.

[Levi B]

I wasn't aware of an updated separator plate, but it is metal so was it replaced before I got the car do you think? It had a silicone "gasket" on it when I took it off. When I removed the flywheel the only thing that appeared to be leaking was the rear main seal. I don't doubt what you said is correct, but my friend and I (he has been working on subarus for years) were very careful about doing things the right way. Are there any other sources of oil that I am missing?

[86bratman]

Sounds like you've got one of the older series seperator plates, they were aluminum instead of the junk plastic they went to around that time period, the ej22 I'm building has the aluminum one as well. Did you notice anything on the trans side, like the input shaft seal?

[harrymaneuvers]

Have you double checked to make sure it is not power steering fluid. Someone correct me if I am wrong but it would be pretty hard for a rear main seal or a separator plate to leak at a rate that would cause smoke at stop lights ect.

I could imagine a drop every few minutes... but that isnt what it sounds like.

[86bratman]

The engine in mine leaks that bad. Its from the back of the engine, so I'm sure it can be from there. When I brought the car home after buying it, 2 hour drive at 60mph, pulled into my parents to show dad. Smoke came up from my hood for a good while. Mine also leaks fron the front main, cams, and valve covers, but I've got a present for the car in a few weeks lol.

[Levi B]

We inspected the transmission side, it had no obvious leaks. Harry I was thinking along the same lines, but I'm nearly 100% sure it is engine oil. I haven't been out to the garage to check the floor yet today but whatever is leaking should be on the floor instead of burned. I'm really hoping it is power steering but I am pretty sure it's engine oil. I'm going to give it a good pressure washing this weekend under the engine, so that hopefully I'll be able to track the leak a little better. Right now it is cleaner than it was before, but still has areas of grease/oil build up. If it does turn out to be the rear main seal or the separator plate I will just have to keep adding oil and live with it. I may even go so far as to fashion a little plate that would re-direct the oil to avoid the exhaust. I won't have time to pull the engine again, starting in a couple days. I really appreciate your quick responses though - and if I do end up pulling the motor again at some point, I'm swapping it with a turbo'd one haha.

[Levi B]

Hallelujah, I just checked the puddle on the ground and it smelled kind of like transmission fluid. I never thought I'd be so happy to check a leak. I need to try to distinguish if it is PS fluid or Trans fluid, but it is not engine oil! I'll report back once I've had a chance to check into it.

[86bratman]

Well, if its definatley atf then its from the steering rack or lines, the 5mt shouldn't have atf in it lol.

[harrymaneuvers]

I can tell you first hand that a leaky power steering line by where it meets the steering rack on the passenger side will difinitly leak down the back of the crossmember and directly onto the exhaust y pipe.

Time to replace it with a braided stainless line and call it a day.

[86bratman]

Do you know a good source for one of them? I'd like to do it as cheap insurance when I have my engine out next month.

[harrymaneuvers]

http://www.technafitstore.com/PSH-S-WRX-p/psh-s-wrx.htm

you might contact Reason to see if he can get it for you.

I like this one over the others because it comes with an optional Black Hytrel coating to not make it stand out so much. It is also plenty big so you can route it whichever way you want.