Assessment of oil leaks

[curlesw]

First, the car/situation: 1983 SC, about 130,000 miles, runs great, daily driver, not driven hard. Oil leaks started about a year ago, got steadily worse, finally got around to looking into it. About 2-3 dime size drops when left overnight. Oil consumption is still about 1 QT ever 900-1,000 miles; use to be 1,500+ miles. Smoke does come from the car if I stop for about the first 10-15 minutes burning off the oil that has leaked onto the heat exchanger.

I cleaned the engine today to see if I could determine the origin of the leaks. The valve covers are fine; no leaks (even though they are dirty). After cleaning the engine, I drove the car for about an hour and then let it sit for a couple of hours, here is what I found:

Picture #1 shows three leaks.


Close-up shots of the leaks:




Picture 2 shows a fourth leak:


The last picture shows the passenger side heat exchanger.



Here are my observations:

1) I cleaned all leaks and they have not returned four hours later, not sure why.
2) The heater tube has fresh oil stains at the very top of the tube.
3) I assume Leak D is causing the smoking, just not sure how fast the oil is leaking.
4) I checked around the air box as best I could without taking anything major off but did not see any oil.

I assume an engine drop is needed to find the source. Just wanted to see if anyone had any thoughts/insights on what it might be.

Thanks for looking

Wayne C.
83 SC

[brendon]

I'll take a stab at this - engine oil cooler o-rings or even t-stat and/or temp sender. Can be fixed in the car (or so I've heard) but much easier with the engine out.

My guess is that all the different drops probably originate from the same spot. I had a bad return tube seal leak (seamed to be coming form everywhere) a few months ago that I swore was coming from above and was fearing broken studs. $2 and a few bloody knuckles later all was well.

[snbush67]

I had a leak in the same area and it turned out my oil cooler had sprung a leak. This looks yo be your problem as well. These can be removed and replaced while the engine is in the car. It may be your oil lines at the cooler...either way I would pull the cooler and have it pressure tested. If you are lucky it may be able to be sealed or pick up a good used one somewhere.

[djdsc]

This isn't mentioned often as a problem, but I also had the engine mounted oil cooler spring a leak in a 2.7. The unit actually had a 1+ inch crack in the welds along the mounting/seal end. It leaked slowly in the area usually identified as a seal leak or a leak from the air box drain from an over fill. When it finally went, it sprayed like a high pressure nozzle.

[Scott R]

Looks like B & C are leaking from above the cooler, more likely to be something on top that's running down the side of the engine, this could also be the cause of A as well.

Pull the rubber intake boot from the air flow meter and get a drop light back there, use a mirror and you should be able to see what's going on. The likely suspect is the idiot light leaking or the breather plate or hose, possibly the t-stat housing. If you have ever had the engine out and down to the long block you can see that oil from components follows a nice little channel down to "B."

[curlesw]

Thanks for the feedback guys, really appreciate it. I have been searching the archives and it seems people with similar leaks had problems with the oil cooler or problems in that general area. Looks like I am in for an engine drop...need to adjust the valves anyway, it's been at least 60,000 miles

The car has been sitting for more than 24 hours since I cleaned the leaks off in the above pictures and no new leaks have formed. I guess that supports the oil cooler or the breather plate/hose idea.

If anyone in the Escondido area is up for an engine drop party let me know. Based on my work schedule it looks like the end of Jan or early Feb at the earliest. I'll start my homework on what it takes to drop then engine...plenty in the archives for sure (and the 101 book first of course).

v/r
Wayne C.

[coloradoporsche]

Wayne's 101 projects book has a nice summary of common oil leaks and how to fix them.

[TroyGT]

I wouldn't drop it for those links. My car had a bad leak exactly where yours is and I swore up and down it was from the oil cooler. It wasn't. I pulled the oil cooler while in the car, inspected, replaced the two doughnut seals and reassembled... still had the leak. My turned out to be loose rocker arms. I opened up the upper and lower on both sides, I had a couple that had walked a little. I tightned everything up and I've been leak free since. I purchased the RSR seals just in case but haven't had the need to put them on yet. I replaced my oil return tubes with new expandables and replaced all the valve cover seals. Very cheap fixes to my oil leaks. Mine were hard to diagnose too. If you've done the searches, then you've seen my threads and pics on what I was experiencing.

-Troy

[curlesw]

Thanks Troy.

I just read your post at seems your leak was more from the valve covers, correct? My valve covers, while dirty, do not show signs of fresh oil. I am going to adjust the valves and will check the rocker arms as well. Thanks again.

v/r
Wayne C.
83 SC

[TroyGT]

There are openings in the valve covers, toward the engine front, that when rocker arms are loose, will allow oil to the exterior and onto the oil cooler itself. My oil cooler was soaked, that in turn dripped off onto the heat exchanger and skid plate, wind also pushed this oil down my main oil tube. Basically the whole passenger underside was wet and smoky. It looked bad, smelled bad, and every indication was the oil cooler. But it fooled me. Do a search for 'wet engine' and you'll see what the underside of my car looked like and everything that I did to alleviate the leak. Good luck.

-Troy

[curlesw]

Did you change the oil cooler seals and all of the other work without dropping the engine? The more I read into what I might need to do, I think a partial drop might be sufficient. My fear is dropping the engine and then 3-4 months of "while your there do this and that" takes over and the car is not useable. The car runs great but just this pesky oil leak and I can't Ax until it's cleared up.

v/r
Wayne C.
83 SC

[TroyGT]

Yes, I removed the oil cooler in my 86 without a partial drop. I replaced both seals and inspected the cooler for leaks. I found no leaks, but I have fresh seals there now and a little more peace of mind. Once the cooler is loose, it takes a bit of juggling and turning to get the cooler turned in various ways to actually get it out of the engine compartment. It's do-able... just takes a little patience. The rocker sleeves are easy to check too, just pop the covers and inspect. If you know what you're looking for it's quite obvious. Mine were loose and had moved or 'walked', which allowed oil to escape.

-Troy

[curlesw]

Thanks Troy. I think I am going to tackle this issue without an engine drop first (maybe a partial drop if needed) and see how it goes from there.

v/r
Wayne C.
83 SC

[snbush67]

FS: Engine Oil Cooler

Just in case you need an oil cooler I saw this advertised. New OEM go for 500 and up.

Even if you don't need a new cooler it is still good to take it out and clean the fins as it is probably caked up with crap.

Good luck

[joetiii]

I am resurrecting this thread because my oil leak relates to this area of the engine. I've got oil all over the front part of the engine and suspected a front seal. However, after reading this thread I am suspect of the oid cooler. My question relates to how quickly an oil cooler will start leaking.

My car just started leaking in that area a few weeks ago and now leaves 2 tablespoons everytime I park the car overnite.

do these leaks suddenly happen?

Do they get progressively worse?

I have an autoX this weekend and don't want to risk popping a line if these go bad fast...

[pete3799]

If you've ruled out leaks from above (thermostat,breather gasket,oil pressure switch, hoses etc)Get some brake clean and spray the bottom of the oil cooler.
Get it as clean as you can, then start it up. If you get a steady drip from the cooler i'd say it's sprung a leak. Will it get worse......probably.

[RSTarga]

I wouldn't worry about those leaks until they get a bit worse. Put a pan under the car overnight and see just how much is really coming out. My only worry would be the oil cooler.

[joetiii]

Agreed, I've got to get it on a lift and clean things up underneath so I can find the source. My only concern is the suddenness and amount of the leak. Started two weeks ago and the tablspoon overnite. I've always had dime spots by valvecovers but never this much. I fear it could pop somehow.