Creamy light brown/tan gunk in coolant tank

[JFP in PA]

Originally Posted by gcorteen

Just spoke to the shop that replaced the oil cooler. They have flushed the coolant system twice with an additive, but the lines running to and from the radiator are still loaded with oil. Not sure if they are flushing with the engine running, is this important? Any other steps that may help?

Sometimes this is a real pain. Once the system is run with a cleaning additive, we use a set up that we made to circulate 135F water through the pipes and forward radiators until the water comes out clear. We then pull the thermostat and do the same thing with the engine. If it does not come clean, we reassemble the system, charge it with clear water and additive, run it for a while, drain it, and then flush it again, always looking for clear water. As I said earlier, we handle intermix clean outs on a time and materials basis because you never know how much work it is going to be………….but you need to get the system clean. It can take an hour to replace the oil cooler, and then take as much as 6-8 hours to clean out the system………

[gcorteen]

Thanks JFP in PA. Can the radiator be cleaned oil without removing it just as well as it could be if it was removed? I am now being told that the only way they can get everything out of the radiator is to take it out for flushing which involves taking off the front of the car.

[JFP in PA]

Depends upon how badly "gunked up" it is; if the passageways become plugged, you have no choice. I have never had to do this, but I have heard of it on a car that was run for a very prolonged period with the intermix problem. You do not have to remove the nose, just the front bumper to get at the radiators. Would be a good time to also clean out the radiator area as they tend to pick up just about everything from leafs to dead birds in there.........

[gcorteen]

Update: Oil cooler was replaced and coolant was flushed, but I was told that they were not able to get all the oil out and I would see residual oil for awhile. I was told to drive it and it should become obvious if it was only the oil cooler that was the problem or if I have a bigger problem as well. I have driven 500 miles since the oil cooler replacement and flush and the car is running 15 degrees cooler than before land everything seems great. I do still see residual (hopefully) oil in the coolant tank and I dip a paper towel in the tank and soak it out. The amount of oil is a small fraction of what it was before. When I look in the tank I can see the chamber next to the main chamber always has more oil in it. Is there a way I can clean out the entire coolant tank and not just the main chamber? Thanks.