1993 940 Oil spewing out the coolant expansion tank

lindy8_man · Post by **lindy8_man** » 26 Feb 2014, 20:16

: 940 oil cooler.png (37.18 KiB) Viewed 1232 times

If you are sure you do not have a blown gasket, look right behind the oil filter is a oil cooler that should have a hose in and out full of coolent. I would look here as this is your oil water interface. see attached photos

Post by **precopster** » 26 Feb 2014, 21:38

Bypassing this with a hose joiner would help you determine if this unit is faulty. Of course your oil will run hotter so drive conservatively.

Post by **98T5** » 27 Feb 2014, 08:57

OH I get it so you guys are saying my oil cooler may have taken a dump...and thus release oil into the expansion tank? my car is NON TURBO... does this matter?

Post by **98T5** » 27 Feb 2014, 08:57

I will post pictures tonight

lummert · Post by **lummert** » 27 Feb 2014, 12:25

eeuroparts.com shows oil cooler parts for 92-95 8-valve and turbo 940.

Post by **precopster** » 27 Feb 2014, 13:18

You really need to work out which fluid is contaminating the coolant. Try the rag test on concrete and see if the concrete stains. Otherwise send a sample away for lab testing.

Way too much labour/cost involved unless you really know which fluid you're dealing with.

Post by **98T5** » 27 Feb 2014, 21:43

OK...here's what I found out tonight. It wasn't the head gasket at all. It was a clog in the expansion tank hose leading to the radiator, which I guess, forced a lil bit of oil back into the return hose of the expansion tank. the clog was from Bars Leak I put in 2 weeks prior.

So what I did was bought a new 3/4 inch heater hose, cleaned out the expansion tank, hooked everything back up to see if I could see "bubbles" in the expansion tank after warming it up. )THIS is the true test to know if your head gasket is toast)....NO BUBBLES!

...So while I was in there I swapped out the old ECT(for fuel injectors), but couldn't get the ECT(for the dash guage) out yet, so I hit that one with some PB Blaster. Took it for a spin and I can feel the difference in power band and pick up speed. It used to "stick" before a shift change, no more. I guess that ECT for injectors was the problem there.

So far so good. no overheating issues, nothing.

**WARNING!!!**** - DO NOT USE BARS LEAK ON THESE CARS, IT DOESN'T WORK!. When I got in there, I noticed a lot of "clumps" of bars leak coming out of the heater hose and right at the opening of the radiator. Right before my breakdown I used this junk thinking I was sealing a hole in my heater core.
I believe this stuff is what caused my overheating issue and oil in the expansion tank in the first place. I'm sure it was blocking the passage of coolant/water and thus forcing trannny cooling oil back into the tank. I learned the hard way on this one.

lummert · Post by **lummert** » 27 Feb 2014, 21:56

I learned 25 years ago not to use Bar's Leak that is in the pellet form. I had a leaking seam on a brass heater core. The heater core plugged up solid after using the Bar's Leak. It was so cold out that the windshield would ice up on the inside while driving home after the heater core plugged. I removed the heater core, cleaned it out with The Works toilet bowl cleaner, soldered the seam, and put it back in.

Post by **98T5** » 02 Mar 2014, 07:55

Turns out it was the head gasket after all. I let it sit idle running for 15 minutes and the oil came back to the coolant again. so I'm doing a head gasket repair on this one.

Post by **precopster** » 02 Mar 2014, 13:44

Did you bypass the oil cooler first? A head gasket's a huge job to undertake without eliminating other possibles

1993 940 Oil spewing out the coolant expansion tank

Re: 1993 940 Oil spewing out the coolant expansion tank