LSJ Oil Cooler?
 

I have a stock 2005 Saturn Ion Redline with an issue. Everything had been normal until on a ~100 mile trip, the temperature suddenly climbed into the red when driving along a 50 MPH road. I slowed down to below 25 MPH until I could get to a safe place to pull over to wait for a tow, and the temperature dropped to just below the red. Foamy brown oil/coolant had blown out of the coolant surge tank and covered the left front wheel well. The engine was about three quarts down on oil. There was no observable coolant in the oil. There was no smoke in the exhaust.

The mechanic that I had it towed to refilled the oil, pressure-tested the cooling system, refilled the coolant, drove the car around the block, then let it idle for an hour. He was unable to replicate the problem.

As I was driving the car home, everything seemed fine. Then suddenly, the temperature spiked and the oil/coolant started spewing out of the surge tank again.

Does this sound like the oil cooler has gone bad? Is there a way to trouble-shoot it without spending a grand on a new part? And if it is the oil cooler, where's a good place to buy one?

Are you sure there is oil in the coolant? I just ask because your coolant could easily be brown as your car is a 2005 and if it has never had the coolant flushed or had green added to the dexcool it can make it brown. The second time you had "oil/coolant started spewing out of the surge tank" did you also observe another sudden loss in oil?

Although it is possible I doubt it is likely that oil is entering through the oil/coolant heat-exchanger.. If it was I would think it would not be intermittent and the mechanic would have seen the problem duplicated. Although it would explain the oil loss I don't know how that could cause you to suddenly overheat either. I wonder if you possibly have a head gasket issue.

You can remove the oil/coolant heat-exchanger and pressure/vacuum test it for leaks. You if you had the right hoses you could probably even test it without removing the cooler by removing only the coolant line and tying onto the nipples there. Alternatively you could remove the coolant lines from the heat-exchanger and either loop them together or plug them off and see if your problem goes away. The nipples on the heat exchanger would only need to be covered to keep contaminants out.

This could be a case of lack of maintenance versus a serious mechanical problem like a blown out gasket. Now is the time to get into the habit of checking all fluids and inspecting the engine compartment at minimum when you fill up with gas; you have a 14 year old value car. You need to monitor this problem in the short-term regardless. There are so many benefits to checking this stuff yourself; including the identification of empty coolant tanks before leaving on 100 mile trips :-D

Science says engine oil will float to the surface of water, so engine oil in your coolant might look like this:
https://cimg7.ibsrv.net/gimg/www.cob...272cf5527a.jpg

Yes, I'm sure of it. See the attached pictures from the first overheating event. After the first mechanic that AAA towed the car to refused to do any more diagnostics on the car after observing "oil in the coolant," I refilled the surge tank with distilled water and drove the car about a mile home (again overheating right at the end of the trip after behaving normally up until then. The second mechanic refilled the coolant with whatever antifreeze he had, and when the car overheated on the way back home after he failed to replicate the problem, the foam looked exactly the same as it did the first time.https://cimg8.ibsrv.net/gimg/www.cob...ebdb6109c2.jpg
https://cimg2.ibsrv.net/gimg/www.cob...09d79358f3.jpg
https://cimg4.ibsrv.net/gimg/www.cob...cd196213d9.jpg
https://cimg6.ibsrv.net/gimg/www.cob...f0665ff2e5.jpg
https://cimg9.ibsrv.net/gimg/www.cob...da2e8e6bf4.jpg


The problem is always "duplicated." The mechanic just didn't run the engine under load long enough to see it. I suspected the oil cooler because this guy on the Redline forums had identical symptoms, and it turned out to be the oil cooler: https://www.redline forums.com/forums/problems-troubleshooting/89048-head-gasket-gone-2.html (remove the space)

I can't find any info on the oil cooler whatsoever - even a part # on engine diagrams! I'm not even sure exactly what it looks like or where it's mounted on the engine!




As I said above, it certainly isn't a coolant issue!

Holy shit those pictures. Could very well be your oil cooler just never heard of that happening. I guess maybe the layers of the oil heat exchanger are separating some when the oil pressure is high enough though that would have more to do with RPM than load.

The heat exchanger is mounted right off the right side of your oil filter housing straight to the side of the block. The easiest method I can see to test it would be to remove the coolant lines and loop them together. Start the engine and raise the rpms. If oil shoots out of the heat exchanger you've found your problem.

That's a good idea - thanks.

Ok, I was able to find an aftermarket oil cooler. Now I just need to get the gasket.

Is this the correct one? https://www.wholesalegmpartsonline.c.../93181988.html

Iirc those are the gasket o-rings for the oil cooler as there are 2 internal and 2 external. You shouldn't need the two internal if you buy a complete oil cooler with mounting bracket. I'd almost think the new oil cooler would come with o-rings but I haven't ever purchases a new one. The O-rings you need are labeled 443 and 431 in the diagram on the web page you linked.

Well, the aftermarket oil cooler and factory gasket set arrived, so I took the car to a shop to have the oil cooler swapped out.

On the ~3 mile trip back home, the temperature went to about 80% of the scale and stayed there. At home, I found the oily coolant once more spraying out of the coolant surge tank and into the wheel well.

Looks like this car is going to the scrap yard. :(

I wonder if you have a badly blown head gasket or something cracked. But yeah like you are implying whatever it is it sounds pretty serious.

i had a similar problem in my towing truck which we are using for towing roadside assistance nyc, but we sold that truck.