I'm in the midst of a mini odyssey with my car's cooling system.
Background: It's a TR250 with no special cooling stuff (e.g.: no shroud, no
electric fan). The heater core is currently not in the loop. It has a new
thermostat, water pump, hoses and return pipe. I don't know how old the
radiator is, but it looks good externally and doesn't leak.
The radiator cap was old and weak, so it wasn't maintaining pressure and the
car was boiling over. I purchased a new cap which solved the problem
immediately. However, the radiator fluid was quite rusty looking and I knew
it had been a long while since the cooling system had been properly flushed,
I purchased a bottle of Prestone Super Flush, some new antifreeze and a
bottle of Redline Water Wetter.
I set about flushing the system. I drained the system, filled it with plain
water, ran it, drained it, then filled it with water plus the Super Flush,
then ran it and drained it again as the instructions indicated. The water
percolating up to the top of the radiator still looked fairly murky, so I
flushed it twice more with plain water. The last time the car overheated,
with water boiling out the escape valve into the overflow tank. I thought,
"Not a problem. The system just doesn't have any antifreeze to raise the
boiling point or water wetter to improve the heat transfer." I then
proceeded to drain and fill the cooling system once again, this time adding
the Water Wetter and about 25% antifreeze, as the WW label recommended.
Still the car overheats. When I look in the radiator and it's down a bit on
fluid, I see little "crumbs" of what looks like rust in the top of the
radiator, so I suspect flow through the radiator is compromised. Today I
pulled the water pump and thermostat to make sure nothing was obstructing
them. Everything looked fine there and the water pump spins freely.
So, is my radiator toast, or can I do something like pull the radiator and
flush it upside down to wash out the "crumbs"?
Thanks,
--
Skip Montanaro - skip@pobox.com
|