1996 Ram 3500 12 valve. About a year ago, it showed oil in the radiator, so I changed the oil cooler. Flushed all the oil out of the cooling system I could get out, and things were fine. One thing I noticed ever since then, temperature would not raise during normal driving. Only time it would actually come up to the middle of the gauge (where it used to run) was when hauling a backhoe or dozer with it. Took forever for the heater to start blowing warm air. Now, probably about 7,000 miles later, it's using oil again. And again have a radiator full of oil. What in the world is going on here? Head gasket maybe? Any ideas? I'm stumped here. I need to figure it out, I've got other trucks I can drive daily, and pull equipment with, but this is also my only welding truck. Any ideas much appreciated.

 

Not sure what the climate is where you live, but if the oil bypass valve in the oil cooler housing sticks shut in cold weather it is not that uncommon for these to blow the oil cooler from too much oil pressure.

A good experienced ear and an automotive stethoscope will hear a gurgle as it is running if it is the cooler again.

The temperature rise issue is likely a failed or missing thermostat. These engines love hot, so replace the thermostat with a real one from Cummins.

It is also quite possible that you have blown a headgasket. If your backhoe is as heavy as my JD 710J, it is more than enough to stretch the headbolts if you nail the throttle at start out.

Given you pull heavy loads, and the age of the truck, I would start with pulling the head and having it checked for cracks around the exhaust valve seats and to be sure it is true. Once it was ready to go again, I would install studs instead of the headbolts. There used to be a guy on here that sold first rate copper headgaskets, try to score one of those too.

Also, do not reuse the old headbolts, they are a stretch and set type that you torque then crack over to set the correct tension. Once tensioned they never will retension to the correct amount of stretch again anyway as the grain of the steel changes permanently.

 

Would the gurgle be heard at the oil cooler itself? I ask this, because the same day I found the oil in the radiator again, I noticed a sound inside the cab, under moderate acceleration, that sounded like running water. Kinda like when you pull the stopper out of a sink to drain it.

My heaviest backhoe is a Case 580 Super M, It's got everything on it (cab, 4x4, extendahoe) so it's not light, but nowhere near as heavy as a 710. The truck is kinda heavy on it's own though, it's rigged up as a welding truck.

It's been cold here, but not what I'd call really cold.

I am wondering though, last friday I was in some pretty bad mud. Bad enough that all the other trucks that were on the job (way out in a cow pasture, replacing electric poles) were pulled by a dozer in and out of the job (that's what we were doing there, the dozer part). I made it all the way in to where the poles were, all the way back out, drug a 40' pole back in, and made it out again. I probably got rougher with it than I should have. Couple of times I went from 2nd to 3rd gear (in 4 wheel drive high), and got on it pretty good when I started sinking. It'll make 35 pounds of boost pretty easily, so I'm thinking head gasket. I've about decided to just do a complete tear-down, see what I've got, and go from there. And I've already decided to go with studs on the head. I know it PROBABLY doesn't need a complete re-build, with just 102,000 miles, but it needs all new gaskets and seals anyway. It sat for about 5 years, and leaks oil everywhere.

 

Here's a couple of pics of the truck if this works.

 

The turbo isn't connected with the radiator at all, so a turbo issue is not possible. I don't see how he can mix it up with the inter-cooler because it has no cap to open up and look into.
It's still pointing toward head gasket. Time for a compression test.

 

The only way I suspect the turbo could have anything to do with it, is the boost pressure blowing the head gasket.