I have an 2003 Montero Ltd automatic 4WD with 88,000 miles never over heated, went to check my coolant the other day an there's this brown frothy stuff in my coolant. What can this be ?? Head gasket ?? I've never seen this before unless there was an integral engine oil cooler in the radiator and it sprung a leak internally but this model has an external engine oil cooler. Anyone can shed light on this I would appreciate it, thanks.

 

Also, there's no coolant/water in the oil and I had an oil change done about three months/500 miles ago and had to add two quarts last Monday.

 

"had to add two quarts" = two quarts has gone somewhere.

"brown frothy stuff in coolant" = two quarts probably gone into your coolant.

quite how is another matter, it's *usually* the head.

 

I would suspect the oil cooler. Can't remember if these are cooled by water. My work vehicle did this (Diesel) and the oil cooler was the culprit. It's a place to start.

 

Well, I can see how it might be the oil cooler if the oil cooler were part of the radiator assembly of which on this 2003 Montero that is not the case, it has an external oil cooler. I've already pulled the heads and had them machined and I am presently installing them but if anybody has any more ideas I would welcome them, it's been my experience working on cars/trucks that I never take anything for granted.