Radiator goo

My honda pilot has 95,000 miles on it and was just serviced a month before I took a trip. It was driving fine and the engine started getting hot. It died as I drove down the exit ramp and the oil light came on just as it died. After towing it to the shop they found white goo in the radiator. See attached photo. They assumed there was a leak with transmission fluid or oil mixing in the radiator. The oil was empty and the transmission fluid was full and clean. When they replaced my motor and radiator they did not find any cracks or area where a leak had occurred. Everyone is puzzled.


“did not find any cracks or area where a leak had ocurred” ?

Are you talking about the radiator or the engine?

Was the engine disassembled for diagnosis AFTER it was removed?

AFTER the replacement engine was installed?

Does the new radiator have an internal ENGINE oil cooler?

If your engine oil cooler is external, I’d seriously consider replacing it as well.

Was a new engine installed?

Or used?

New radiator cap?

New thermostat?

New water pump?

I would flush the heater core. That 'goo" is probably in there as well.

From the time the engine temperature began to rise until the engine died is the $6,400 question. Was that 30 seconds, 5 minutes or “I’m not sure but it was the first SAFE exit.”

Don’t get me wrong. Better a blown engine than a totaled car and injured occupants due to rushing for the break down lane with the engine off. Count yourself lucky and deserving of congratulations for keeping yourself and others from being injured.

If the engine is properly replaced and thoroughly road tested before delivery there is no need for an autopsy of the deceased engine. Let it rest in peace. And a proper job should include flushing that heater core.

"The oil was empty...."

Presumably the lack of oil was a result of something else… or was it? I don’t see directly how it would have caused “goo” in the coolant. However the OP needs to be aware that oil level should be checked regularly, both immediately after a shop does an oil change (it happens too often that quickie oil change places forget - yes really - to add oil or tighten drain plug), as well as thereafter. Depending on the condition of an engine, oil will be consumed by the engine and oil level can fall below the minimum. Therefore it’s vitally important to check oil level, perhaps every fill up, or a few times a month, or more often depending on miles driven. Every 500 miles or so is not too often in some cases, and always before beginning a trip.

Hmmm.I don’t know if they replaced the heater core. I’ll have to check. They didn’t find any cracks on the engine nor radiator. Yes, I got a new motor but not a new water pump. Thanks for the ideas.