86'928S MeteorGrey

Got the 89 registered today after jumping through a few hoops. Drove home to start the front end teardown/RE-Rebuild...

Noticed mucky oil filled water leaking from the coolant tank!!!

I first suspected trans oil... But It smells like engine oil. Yes engine oil is low.
I just mopped it up and closed the hood.

I'll tear into it tomorrow. At this point I'm just praying it is the standard oil cooler leak in the radiator. I guess this could be why I'm getting low oil pressure....

I'll drain the radiator, engine and trans just to be sure for diagnostics. I loaned my compression tester quite a while back and it was never returned, so I'll have to pick one up tomorrow. ****.

soontobered84

Damn Mike, I hope you get it squared away. Hopefully you just need a new oil cooler.

86'928S MeteorGrey

I've got the radiator from my 86.5 sitting out on my bench. Will it work, or are they different? I havn't had a chance to do any comparisons yet...

Can the Devek radiators still be found, or are they long gone?

Mike Frye

Hey Mike,

For testing the radiator you don't need a pressure tester, just a bicycle inner tube.

Get one that doesn't have a hole in it and cut it.
Stretch one end over the top radiator hose fitting on one side and one side tank, then the other on the lower with hose clamps and clamp them down.
Then put a small piece of hose on the upper radiator return fitting and plug the end with a drill bit or something so that doesn't leak.

Now if you fill the inner tube up with air using the regular air valve, you should be able to hear the air hissing out through the oil cooler opening if there's a leak. Alternately you could submerge it in a shallow tank of water and look for bubbles.


For the radiator, I think the OB and S4 Rads are different because of the electric fan setup. I know the fan shrouds are different and I'm pretty sure the stock rads are too. The aftermarket ones are usually built to accommodate both, but not stock. 928 Intl has a really nice new aluminum radiator available, and so does Carl at 928MS.

Good luck.

Vlocity

Mike,

Thats a great test rig...I'll have to remeber that !

Ken

Mike Frye

Wish I could take credit for it. I think Jim Bailey is the first one that I heard it from. Simple and very effective though. I used it to identify and test the problem with my leaking side-tank. Got it fixed and no leaks now!

Mark Anderson

[QUOTE=86'928S MeteorGrey;6731235]

I'll drain the radiator, engine and trans just to be sure for diagnostics. I loaned my compression tester quite a while back and it was never returned, so I'll have to pick one up tomorrow. QUOTE]

Mike I've got one you can borrow.

BBX

Mike, can you explain what you mean by "standard" oil cooler leak in radiator? How does the oil cooler leak into radiator?

86'928S MeteorGrey

The radiator on some 928's have an oil cooler and a transmission cooler internal to it. Some just have the transmission cooler internal to it. If it fails, the oil (or tranny fluid) can pressure inject into the coolant. This type of failure commonly shows no coolant in the engine oil. When oil gets into the coolant, it is usually through a failed radiator, a failed head gasket, or a cracked block or head. What weight oil was used when the oil was last changed? If the oil is already 20-50, then low oil pressure can be an indication that the oil pressure is being lost because it is injecting into the coolant system, or into the comustion chamber. Since I am not seeing smoke from the exhaust, I don't believe it is going to the combustion chamber. In the short time you had the car, did you notice it consuming a lot of oil?

I'm hoping when I compression test the engine a,d pressure test the radiator tonight I will find a failed radiator, and not a failed head gasket or cracked block.

docmirror

Argh! Hope this is not too bad. Pull your plugs and look for one that is white, or real clean. Radiator is bad enough, but I don't want to hear head gasket issues.

I think Roger at 928sRus has a source for rads at a decent price. Check if yours has both oil, and trans coolers in it.

BBX

I wouldn't even know if it consumed oil as the only mileage I put on the car were driving home from picking it up from the guy that didn't come through with money. I think I have at the most, 10 - 15 with the car. I believe it has 10-40? I can't remember. I do remember using semi-synthetic though.

Edit: One other thing I just thought of. That guy had mentioned putting some type of additive in the the oil or coolant. I wonder if that's what the milky stuff is?

86'928S MeteorGrey

No. This is thick gooey milkshake, not additive. The oil looks very clean. The car didn't overheat at all when it started leaking. Could be the additional oil in the system, or a cracked coolant tank. Time will tell. I'll keep you posted.

JHowell37

From what I understand, the Devek radiators are the worst of the aftermarket options, and the C&R from 928 Intl or the one from Carl are much better.

Go do a search for my post on replacing the radiator side tanks to find out how to remove them without destroying the mounting tabs, and how to put it back together without leaks. If your oil cooler is leaking, and you wish to repair the radiator, you'd be better off replacing both tanks at the same time.

If you don't have coolant showing up in the engine oil, then I'd say the cooler is leaking. The oil is under much higher pressure then coolant, so it will be forced out, but very little (if any) coolant will be allowed in.

86'928S MeteorGrey

I'm hopeful that it's just the radiator/coolers. I'll dig into it some tonight, but I think the major teardown and inspection is going to happen this weekend now.

86'928S MeteorGrey

Thanks!

I'll call Roger to check on availablity.