A bit of oil in my M35A3 coolant

[Trailfinder]

Replacing the shutterstat on my M35A3 required draining the coolant. When I drained the coolant it appeared dirty. When I poured the coolant into 1 gallon jugs from the 5 gallon pail I drained the coolant into, I noticed residual oil on the bottom of the 5 gallon pail.

I searched the SS posts and found info on 5 ton and M35A2 oil coolers being responsible for oil in the coolant.

Is this a possibility on the M35A3? If so, does anyone know where to get a seal "rebuild" kit for the oil cooler of a M35A3?

Shutterstat problem solved. Fan clutch works now. Oil in coolant not good.

 

[DHennon]

If you have the Caterpillar engine, try your local Cat dealer.

 

[Heavy D.]

Did you find the problem? I just now came upon the same problem.

 

[rosco]

While I don't have an A3, I have had that problem several times in commercial trucks. The oil cooler intself, springs a leak - its not a gasket problem. Replacing the oil cooler, solves the problem. Then before I refilled with antifreeze, I refilled with plain water, added a whole box of Cascade powdered soap (its low foaming), put a tarp over the radiator, and let the engine run @ 1500+ for an hour. Then flush a couple of times, and refill with antifreeze.

 

[5tontiny]

Agreed ^^^ Rosco hit the nail on the head.. I've found this to be true a time or two.

 

[clinto]

I have an unusual case. Drained the coolant from an A3 with reasonably low hours and mileage (500 hours, 5K miles app.) and oil is in the coolant. So I assumed head gasket, oil cooler, etc.

Continued to drain fluids (this is a full service job) and the engine oil was exactly the right amount and no coolant contamination. Same thing for the trans. So the only thing that's contaminated is the coolant. I am thinking somebody accidentally poured some oil in the overflow tank, realized their error and didn't bother to flush it.

If there was a leak somewhere in the system (oil cooler, gaskets, etc.) there would have to be contamination somewhere else. I don't see oil being able to get into the coolant but the coolant not being able to get into the oil.

 

[rosco]

Old saying: "Do the Math". Oil pressure is 60/70#. Coolant pressure, 15#

 

[Heavy D.]

I haven't posted in a while, and I had this same symptom on my own thread that I have not followed up on yet. I had it looked at by a pro, and he determined that it was not oil but fuel. Thinking about it they look a bit similar to someone not too familiar. Anyways the problem was the fuel injector cups were leaking... Apparently that is a common problem with the 3116. After trying to replace the cups failed, due to the copper washer being stuck in place and mutilated, the only option was to replace the head YUCK! Very very expensive. I hope this helps. Good luck!

 

[gimpyrobb]

Ouch! Sorry to hear it.

 

[ehinlein]

Trailfinder,

Hope you solved your contamination problem. My shutterstat is bad also. Do you remember the PN? Did you get it from Cat?

Thanks in advance.

Erich