96 850 R Radiator resevoir spewing oil

greg850r · Post by **greg850r** » 22 Oct 2016, 04:35

So my wife is driving down the highway at 60 mph or so when I notice what looks like smoke emitting from between the passenger fender and hood for a second, look over at the dash and see a pegged temp gauge and the oil light wink once or twice. She turns the key off and coasts to the shoulder. I open the hood and it's starting to boil and the fluid is black. Pull dipstick, crankcase empty. Left it to get truck, trailer and the jug of drain oil from the last oil change. Return, add 5 quarts it starts and pulls itself on to trailer. I'm relieved to say the motor sounds good doing it. Figuring oil is either getting pumped into cooling system at radiator or head gasket. Perplexed to find no antifreeze in oil though. Was ready to mothball this one for winter anyway and put her in a sedan that I have just about ready to go so I won't look at it this week. I was looking for suggestions on troubleshooting source of problem. Thanks.

Post by **abscate** » 22 Oct 2016, 05:12

You need to sort out if it's oil or ATF.

Oil comes from head or oil cooler leak

ATF from the trans cooler integral in radiator

Run a compression test before you bed it for winter, that might point to a head gaske t problem

Post by **Ozark Lee** » 22 Oct 2016, 08:26

The oil runs at 40 to 50 PSI and the coolant runs at pressures in the low teens. When there is a breach it tends to be a one way street from the oil to the coolant. A bad oil cooler in the radiator is fairly common source of coolant /oil contamination but if it got real hot then all bets are off.

...Lee

Post by **sleddriver** » 22 Oct 2016, 18:10

I agree with Lee. Had the oil-cooler-in-the-radiator rupture, fill the overflow tank with oil/coolant mix, but found no evidence of coolant on the dipstick. What a PITA as I was going to visit family the next day.....at least my previous SAAB had a separate engine oil-cooler.

i Roll laid an egg on this design..........

beigg · Post by **beigg** » 22 Oct 2016, 20:56

Loop the engine oil cooler lines together with a barbed fitting and clamps, Flush the radiator a few times with straight water until it's spitting out clean, non milky substances. Then either loop the radiator's upper and lower oil cooler ports together or plug them off. Quickest cheapest bypass until you can order in a new radiator and supporting parts.

beigg · Post by **beigg** » 22 Oct 2016, 21:00

greg850r wrote:Pull dipstick, crankcase empty. Left it to get truck, trailer and the jug of drain oil from the last oil change. Return, add 5 quarts it starts and pulls itself on to trailer.

abscate wrote:You need to sort out if it's oil or ATF.

Run a compression test before you bed it for winter, that might point to a head gaske t problem

I would go with it being engine oil based on the OP's info. However, check the transmission fluid for level/condition too! It may have breached both aux coolers.

I'd run that comp check as well. Can't hurt.

Post by **sleddriver** » 23 Oct 2016, 12:20

beigg wrote:Loop the engine oil cooler lines together with a barbed fitting and clamps, Flush the radiator a few times with straight water until it's spitting out clean, non milky substances. Then either loop the radiator's upper and lower oil cooler ports together or plug them off. Quickest cheapest bypass until you can order in a new radiator and supporting parts.

Adding a bottle of the laundry cleaner SHOUT helped me rid my cooling system of oil contamination. My indy suggested it!

greg850r · Post by **greg850r** » 24 Oct 2016, 06:50

: fitting.png (107.24 KiB) Viewed 1224 times

: fittings.png (85.81 KiB) Viewed 1224 times

Check out the tool I made from some parts I had laying around. Changed oil, plumbed lines together, car ran, coolant pouring out oil cooler fittings on radiator. Trans looks good so no failure on trans cooler side. Lack of coolant in system when I pulled lower hose though. I wonder where it all went. May be looking at a head gasket once system pressures up with a new radiator.

beigg · Post by **beigg** » 24 Oct 2016, 12:01

Soon if not already leaking in the cabin area, your heatercore. It wasn't intended to take beyond 30 PSI, and by the oil pressure overtaking the cooling system, I'd plan on replacing that soon.

greg850r · Post by **greg850r** » 24 Oct 2016, 18:08

Good call, you're probably right and I didn't even think about it. What is the let go point on the green reservoir cap anyway? That would have been the most pressure it saw.