Before I bought it, I drove it for 45 minutes and on the freeway. I checked all the fluids. No smoke. Slight blow-by. At the time I could detect no oil in the coolant and the oil was at the correct level. The car ran 5-10C degrees warm at 60F ambient. The only hint of this problem was a very slight pulsing at the exhaust I thought was dirty injectors, fuel filters or an alda issue. As the ambient temp rose, the car began to run hot, up to 235F, after an hour on the freeway with the a/c on.
I took it to a mechanic who said he pressure tested the system after I suggested it might be the head gasket. He supposedly dropped the pan and checked for coolant in the oil and changed the coolant and checked for oil in the coolant and said he found none. I checked for residual pressure by checking the radiator hose when it was cold in the morning. Nothing. Yet the car was running hotter and hotter. So per his suggestion over a few weeks, I had the radiator rodded, new aux fan, new thermostat, new radiator cap etc.
While chasing the cooling issue after the mechanic gave the head gasket a clean bill of health, convinced I'd be able to solve the cooling issue outside of the head gasket,
I dropped about $1500 and hours of sweat into it.... New A/C compressor, dryer, tires, brake hood pad, filters, new belts, return lines, valves, etc. etc...thinking I'd eventually solve the cooling issue.
I over-filled the coolant in my expansion tank. I left it over night after driving it and discovered brown/black floating globs.
I couldn't see these before because you can't see the coolant through the cap hole if it is filled correctly to the arrow. You have to over-fill to see the oil in coolant.
The car still needs about $1800 in work if I have it done, not including Est. $2000 cosmetics, paint, body, before head gasket. The car has 300k miles. As it's outside of my abilities, I estimate the head repair could be done at $800 cheap and $1300 correctly.
So, before investing that type of money, I'm going to try the Nanotechnology K&W Head Gasket Repair with the double your money back guarantee. I'll let you know whether it works or not.
Any comments or suggestions are appreciated.
Also, could the added pressure of a 140 radiator cap have contributed to the gasket issue? It had a 120 before and the cooling circuit is smaller due to the heater core being bypassed.