Thank you for the replies! Is there anything specific I should check or do for airflow through the radiator at speed? The nose is empty except for a bottle of spare coolant where the spare tire used to be.
Am I correct to leave the fan off, except at low speeds or in traffic? I've not observed any benefit to having it on at speed. It does work to keep my temp down when in in-town traffic.
Thanks for the check list John.
- ignition timing ok. --- I'll check it again. I have not checked it recently because the car has been running great.
- carb not set lean. --- I run rich, as judged by the plugs (and exhaust smell). I was set up at sea-level but the lowest point around here is 4,200'.
- coolant a 50/50 mix of water and antifreeze. --- Yes 50/50. Changed three times in the last 8 years, most recently this month. It had been about 5 years since the last flush and change. The car was in storage for about 20 years before being put back on the road in 2012. I doubt it was changed while in storage and the cooling system suffered from that. I have flushed the hell out of it using a garden hose and coolant system flush (the acidic stuff). The first flush was downright nasty! Subsequent flushes have been rust stained but with much less "sediment." Stainless transfer pipes are on my long term to do list.
- rad cap ok. --- The cap was new 8 years ago. With this flush I replaced the cap. Both were Stant, 7 psi. Is it worth testing a new cap?
- coolant leaks. --- No visible leaks. The coolant level stays constant (unless it overheats).
- coolant low. (air locks) --- I do believe this was my problem, but only one time. Bleeding this system is not so easy.
- rad baffle in place. --- Based on flushing the radiator directly, it seams water flows through the radiator before exiting. Is there a better way to check this?
- thermostat opens at its rated temp. --- I just checked my notes and I have not changed or checked the thermostat. I will do this. (The car does come up to temp and then stabilize, only over heating when ambient temperature is high or on long uphill hauls at speed)
- rad fan turns on at the switch's rated temp. --- My Otter switch does not seem to work but I have and use an override switch at the dash. I ordered a switch for the new radiator, but it is not the issue currently.
- rad fan running the right way. (pushing air through the rad) --- The fan seems to be effective at slow speeds in traffic. I turn it on and the gauge moves down or stabilizes. However at maintained speeds I generally have it off, thinking it would not do anything, or might even impede flow. Is this generally correct? My heating problems have been at higher speeds.
