Legacy 1995 leaking oil when driven at "high" rpm's

[Cruzerider]

Hi folks,

 

our Legacy recently decided to make more problems than I like. His newest thing is to leak motor oil when driven at higher rpm's (around 3000 and above).

An inspection by a mechanic a couple months ago basically found a possible leak at the oil pan gasket and/or the front and/or rear seal. I am assuming it's the crankshaft seal that is addressed by that.

 

What is happening is that every time we drive a longer uphill, usually on the highway, oil starts dripping from 'somewhere' onto the exhaust pipe, resulting in smoke from the oil being burned. This problem does NOT occur when driven at lower rpm's, i.e. in town.

 

My conclusion is that there is a problem with a leaking gasket somewhere, the gasket only leaking at higher pressure inside the 'engine'. Can you guys make any sense of my description and conclude where the leak could be? I am kind of worried it might be the crankshaft seals which would be more trouble than the oil pan?!

 

Another thing I noticed and wasn't sure if it's a problem or 'feature': when driven at very high rpm's (4500+), the engine makes a "whistling" noise. Hard to put in words, it's kind of a high pitch tone. Is that what it is supposed to do or is that an indication of another problem?

 

 

Thanks so much!

[gbhrps]

I'm not sure that this is the cause of your problem, but it sounds similar to the situation that I experienced in one of my cars several years ago.

 

A leaking rear engine seal would deposit a silver dollar sized circle of oil on the garage floor after each run. This was on a 1990 Nissan 300zx, and about 8 years ago. On a similar forum someone suggested changing the PCV valves (that car had 2 of them), figuring that if they were stuck in the closed position, that they would allow internal crankcase pressure to build up and push oil out through the rear seal.

 

I changed them and the leaking stopped immediately. I still own the car and it has not leaked a drop to this day. It saved me from having to drop the exhaust, the prop shaft, the tranny and the clutch to replace the rear seal.

It was a very cheap fix.

[Fairtax4me]

Rear main leaks on these are the only leaks that are NOT common. Entirely possible, but it would not be my first suspect.

Usually leaks at the back of the engine are due to the oil separator plate seal. This is a much discussed topic here. The oil separator is part of the crankcase breather system. At higher RPM there will be more oil vapor floating around in the crankcase, which is filtered out (somewhat) by the separator plate, before being pulled out through the PCV hose and fed into the intake to be burned off. That extra oil vapor will condense and run down the plate, as it normally should. But when it gets to the bad seal at the bottom, rather than run down into the oil pan, it drips out the back of the engine, down to the center of the bell housing, and drips out right into the middle of the Y pipe.

 

I've never noticed my 96 "whistling" at high RPMs. Any accessory or idler bearing on the front of the engine might make whining/jet-like noises at higher RPM though. How many miles on the car? When was the last time the timing belt was changed?

[nipper]

Hi folks,

 

our Legacy recently decided to make more problems than I like. His newest thing is to leak motor oil when driven at higher rpm's (around 3000 and above).

An inspection by a mechanic a couple months ago basically found a possible leak at the oil pan gasket and/or the front and/or rear seal. I am assuming it's the crankshaft seal that is addressed by that.

 

What is happening is that every time we drive a longer uphill, usually on the highway, oil starts dripping from 'somewhere' onto the exhaust pipe, resulting in smoke from the oil being burned. This problem does NOT occur when driven at lower rpm's, i.e. in town.

 

My conclusion is that there is a problem with a leaking gasket somewhere, the gasket only leaking at higher pressure inside the 'engine'. Can you guys make any sense of my description and conclude where the leak could be? I am kind of worried it might be the crankshaft seals which would be more trouble than the oil pan?!

 

Another thing I noticed and wasn't sure if it's a problem or 'feature': when driven at very high rpm's (4500+), the engine makes a "whistling" noise. Hard to put in words, it's kind of a high pitch tone. Is that what it is supposed to do or is that an indication of another problem?

 

 

Thanks so much!

 

 

HIgh pitched noise is most likely the Airbox (where the filter is ) is not seated properly.

 

How many miles and when was the iming belt last replaced.

 

Replace the PCV valve as that will take pressure off the seals.

 

Seperator plate is a good possability as these cars almost never have a bad rear seal.

[Cruzerider]

Thanks for all the answers! Some more input from my side:

 

> the car has 185,000km on the odometer. Nothing too crazy for a 1995 I'd think.

 

> no idea when the timing belt has been changed last. We only got the car at the beginning of summer, not much information on maintenance was forwarded.

 

> will look into the other possible leaks you guys mentioned and see if I can get the PCV valves fixed.

 

> Airbox, filter, timing belt to be checked for being reasons for the noise

 

Any links to helpful information on the stuff you guys mentioned would be very much appreciated!

[nipper]

You may be overdue for a timing belt. You have 114,000 miles. It is due at 105,000 miles or 105 months. I would have it changed.

 

Also at the same time you change the front cam seals, main seal, idlers tensioners water pump and thermostat. CHeck your valve covers and spark plug wire ends for oil.

 

You need to wash the bottom of the engine using a engine cleaner and a high pressure wash. Drive the car for a day or three, and look where the leak is coming from. on a subaru it is hard to see the source of leaks. The speration plate may be the source. Then the engine has to come out. If that is the source, then have the plugs, vlave cover gaskets replaced too. They are MUCH easier out of the car.

[1-3-2-4]

I need to do my cam seals between the two and the real separator plate leaking I need to add some oil about every week but not a qt worth.

[Gloyale]

Hi folks,

 

our Legacy recently decided to make more problems than I like. His newest thing is to leak motor oil when driven at higher rpm's (around 3000 and above).

An inspection by a mechanic a couple months ago basically found a possible leak at the oil pan gasket and/or the front and/or rear seal. I am assuming it's the crankshaft seal that is addressed by that.

 

What is happening is that every time we drive a longer uphill, usually on the highway, oil starts dripping from 'somewhere' onto the exhaust pipe, resulting in smoke from the oil being burned. This problem does NOT occur when driven at lower rpm's, i.e. in town.

 

 

I would wager that the engine reaches 3000 rpm sometimes, even in town. What seems more consitant in this case is that it happens at freeway speeds.....not nescesarily an RPM issue.

 

I would propose that it isn't an issue of engine RPM, but of vehichle speed. Specifically the speed of the front differential in the trans.

 

The front diff drags through gear oil, and as it does, it slings a stream of fluid. This fluid flies directly onto the front seal of the trans input shaft. The faster you go, the more it slings.

 

When the seal get's leaky (usually because of a bit of play in the support bearing) then it starts to leak when you drive consistantly at high speed. Leaks directly onto the exhaust crossover. Excactly where you would see oil from a rear main or seporator leak, but this isn't oil.....it's Gear oil.

 

My guess. Try to examine the oil and see if it has that funky gear oil smell or if infact it is just engine oil.

[Suba9792]

check your PS pump, the newer versions are prone to leaking, and it can make its way down the side of the heads and block and onto the manifold. The whistle sounds like the "mystery turbo" whistle for the pump at high RPMs. Replace it with and older model 92-94 I think, I just did mine about a week ago, no more whistle. But I'd do the t-belt and seal job too! get OEM seals from the dealer. Be sure to replace the WP. Import experts is a great place to get those parts, but their gaskets and seals suck IMO. RESEAL THE OIL PUMP!!

[mountain brat]

ditto on ps pump and also check little cover on back of pas head the orings go bad

[Cruzerider]

Hey folks,

 

thanks again for all the input. I had two engine savvy friends have a look last week, things we found:

 

> rear right camshaft seal is possibly leaking.

 

> a possible leak at the hose that runs from the pcv valve down towards the engine block (at the lower end of that T-section)

 

> PCV valve not working properly, should be replaced (possibly along with all the hoses in that area)

 

> We cleaned the area of the leak and observed further, results being that there is possibly another leak lower than the rear right camshaft seal. I couldn't really see well enough to figure out what is leaking. Looks like it is close to the hole in the crossmember (I think that what it is, the thing the engine sits on basically) where these 2 small tubes are running trough. That's exactly where the oil is dripping on the exhaust pipe. Easy to see as there are black burn-marks there. Is the oil separator plate there?

 

> Oil is dripping from the low points of the timing belt cover. That said, we assumed it is because of a leaking left front camshaft seal or possibly the main seal? Couldn't really take a closer look.

 

The main questions I have...

 

> Do you guys think we are on spot with what we found?

 

> How about that separator plate, couldn't quite make any sense from the shop manual.

 

> Would we need to get the engine out for any of the fixes?

 

> What do I have to expect in terms of workload?

 

Any pointers to manuals, instructions would be highly appreciated.

 

Thanks guys, wouldn't know what to do without your input.

[nipper]

Step 1 - remove engine.

 

Seriously. it will mae everything so much easier for you. Basically you are going to reseal the engine.

 

You will replace all seals and the separator plate, and the plugs. This job goes much quicker ans with far less bloodshed with the engine out of the car.

 

Everything sounds logical, just one word of advice.

 

DO NOT MESS WITH THE REAR MAIN SEAL!

 

if it is not leaking leave it be. Playing with it is like waking Godzilla from a long hibernation, no one is ever happy when that happens.

[Fairtax4me]

Heres a good write-up with pics for the oil separator. http://beergarage.com/SubySeparator.aspx

 

It sounds like you have all of the common leaks on subarus. But the plugged PCV valve was causing higher crankcase pressure which contributed to oil pushing out through some of the seals. Replace the PCV, degrease the engine and check for leaks again in a few weeks.

[Olnick]

+1 on replacing the PCV. Be sure to replace the hose that connects it to the engine block too--it can have virtually invisible splits at the base.

 

You can re-seal the front end without pulling the engine. But to get to the separator plate you'd have to pull it or drop the tranny.

 

Good luck.

[greenleg88]

Hi folks,

 

our Legacy recently decided to make more problems than I like. His newest thing is to leak motor oil when driven at higher rpm's (around 3000 and above).

An inspection by a mechanic a couple months ago basically found a possible leak at the oil pan gasket and/or the front and/or rear seal. I am assuming it's the crankshaft seal that is addressed by that.

 

What is happening is that every time we drive a longer uphill, usually on the highway, oil starts dripping from 'somewhere' onto the exhaust pipe, resulting in smoke from the oil being burned. This problem does NOT occur when driven at lower rpm's, i.e. in town.

 

My conclusion is that there is a problem with a leaking gasket somewhere, the gasket only leaking at higher pressure inside the 'engine'. Can you guys make any sense of my description and conclude where the leak could be? I am kind of worried it might be the crankshaft seals which would be more trouble than the oil pan?!

 

Another thing I noticed and wasn't sure if it's a problem or 'feature': when driven at very high rpm's (4500+), the engine makes a "whistling" noise. Hard to put in words, it's kind of a high pitch tone. Is that what it is supposed to do or is that an indication of another problem?

 

 

Thanks so much!

 

i experience that higher pitch tone.. and as far as i know.. i believe it is simply my AC belt needing a tightening... i know this becuase it squeaks when its warm out but when its cold, the squeak goes away. but in both cases, it squeaks when its spinning up past 4000 rpms.... perhaps its a similar situation.

[1-3-2-4]

+1 on replacing the PCV. Be sure to replace the hose that connects it to the engine block too--it can have virtually invisible splits at the base.

 

You can re-seal the front end without pulling the engine. But to get to the separator plate you'd have to pull it or drop the tranny.

 

Good luck.

 

My hose that goes to the engine block is split as well what effects would it have? I just never got around to replacing it.. I did replace the line that went to the FPR because well.. that hose just snapped.

[naru]

My hose that goes to the engine block is split as well what effects would it have? I just never got around to replacing it.. I did replace the line that went to the FPR because well.. that hose just snapped.

 

It will suck grit into the engine and blow oil out.

[Fairtax4me]

My hose that goes to the engine block is split as well what effects would it have?

It's a vacuum leak. Can cause rough idle, misfires under load, etc.

[1-3-2-4]

Im not sure if I can find a replacement hose I was lucky enough to get a replacement for the FPR one.

[nipper]

It's a vacuum leak. Can cause rough idle, misfires under load, etc.

 

 

too much turkey, i read that as mistress under load.

 

It can cause those plus exhuast smells under the hood. it is amazing what a little PCV valve can do post 1990 cars

[Fairtax4me]

Im not sure if I can find a replacement hose I was lucky enough to get a replacement for the FPR one.

Go to advance or autozone or checker or napa or whatever, and buy a foot of appropriate sized rubber emissions hose. Do NOT get heater hose, it will swell and give you more problems than you have now. Emissions hose is made for oil/fuel so it will not swell or harden like ordinary rubber hose.

 

too much turkey, i read that as mistress under load.

Well we know where your mind is!

[LeolaPA]

I would wager that the engine reaches 3000 rpm sometimes, even in town. What seems more consitant in this case is that it happens at freeway speeds.....not nescesarily an RPM issue.

 

I would propose that it isn't an issue of engine RPM, but of vehichle speed. Specifically the speed of the front differential in the trans.

 

The front diff drags through gear oil, and as it does, it slings a stream of fluid. This fluid flies directly onto the front seal of the trans input shaft. The faster you go, the more it slings.

 

When the seal get's leaky (usually because of a bit of play in the support bearing) then it starts to leak when you drive consistantly at high speed. Leaks directly onto the exhaust crossover. Excactly where you would see oil from a rear main or seporator leak, but this isn't oil.....it's Gear oil.

 

My guess. Try to examine the oil and see if it has that funky gear oil smell or if infact it is just engine oil.

 

I just noticed that my front differential oil level was low, so I topped it off, and in doing so over filled it. I don't know the amount of fluid that the dipstick measures between the filled line and the low line, but I probably only put in half a bottle of gear oil. Anyway, I took the car on a 60 mile trip last night where I was hitting 70 at some times. When I got partway there I saw smoke coming from the back of the car and smelled gear oil. At my destination I saw that there was oil dripping off the exhaust system similar to what you describe above. I just don't understand where this is coming out. Would it be where the driveshaft connects, or somewhere else? I saw another thread on here of a guy replacing a "front seal" where he had the tranny all torn apart. Hopefully that is not it!

[Fairtax4me]

If you smelled gear oil there is a good chance it is coming from the input shaft seal on the front of the transmission. And yeah that's the one that requires the transmission be taken all apart to replace.

[LeolaPA]

If you smelled gear oil there is a good chance it is coming from the input shaft seal on the front of the transmission. And yeah that's the one that requires the transmission be taken all apart to replace.

 

Today we drove the car to church in an effort to maybe burn off the oil and see what was going on. 10 mile trip both ways. On the way home, the car stalled at the stop sign, which is weird. As we are driving, the smoke is continuing. I got it home, and decided to check to see if the diff. oil level is lower now. NO, it was not. It was still over the Full mark. Then I checked the AT fluid level. Below the the end of the dipstick. I put in 1.5 quarts, but it still isn't up to full. I decide to pull the car into the garage, and see a trail of ATF fluid behind the car into the garage.

 

So it looks like there is some major leaking going on of the transmission, and I don't know why the differential shows more than full, when there is so much oil everywhere.

 

Could this seal blow, and cause the car to leak ATF somehow?

 

If it is a trans removal solution, I may just get rid of it.

[LeolaPA]

Jacked the car up, and it seems like ATF is coming out of the back of the trans at the driveshaft.