Overheating SE: pump, rad, hoses, fan?
 

The SE started overheating, almost reaching the top of the dial before I was able to cool it by turning on the heater (in this hot 85 weather) and coasting downhill in neutral. I actually drove home on the freeway by coasting down the hills and easing up the ascents. When I cool it down there is a cup of coolant missing and the cap doesn't hiss at all when I open it. Cooling down on the freeway suggests that it's the fan, but the fan is going Ok when I lift the hood. My inclination is to replace the pump (I have spare), radiator and hoses. Too bad I just threw out the spare fan/clutch I had after years of no need for it.

I'd suspect the radiator.

Vernon

Yeah, sounds a lot like a leak, tho there's no water on the ground., it's probably escaping as vapor.

1- Stuck Thermostat???

2- Check the Weep Hole on the Water Pump for Leak.
Any trace of AntiFreeze or Water in that area will indacate Bad Water Pump.

3-Flush System and Do the 60-40 ie More Water than AF and add some Redline Water Wetter. My Temps dropped an average of 7-10 degrees on above 85 days.

Just throwing some stuff here @ Ya
steve
sgieldon

Good points: I forgot about the pump weep hole. And I figure I can afford to fuss with the coolant since I have 2 other FBs to drive around. Replaced the tstat with an OEM last summer, but I'll check it. I'll probly replace the rad anyhow, just on general principles since this SE has 150k on it. That'll make a clean sweep of rads on my 4 rotaries in the last 2 years.

I'm gonna drive one of the 85s to the midwest in a month or two to put it in a shared container with a friend who's shipping to Europe so I can have a 7 there to drive on those lovely country lanes. That's where the sports car was born.

Clutch fan maybe shot.

A way to test it is to note when engine is HOT turn off the motor, then try and rotate the fan. It it spins fairly easily then it's time for a new one.

if it's good then the motor is hot and the engine is off, try and move the fan, the clutch is enguaged it won't move.

Remember the engine must be hot!! and turn off your engine!!


Other causes are plugged up rad (dirt in the fins), low on coolant.

Low on oil causes temps to rise like crazy!

I think the fan clutch is OK, behaves normally. I'd replace it anyhow, but I threw my spare out a couple months ago after not needing it for years. Maybe I'll get a JY unit before I take the rad out, just to be complete.

I'll check oil: good idea. After World Cup final.

Oil was at low end of mark, so I added a quart. Drove it around in the cool of the evening and it was OK. But it seems unreasonable that only low oil would cause a problem. I'll replace rad, pump and hoses when the rad arrives on my doorstep in a couple days.

Whichever one is going overseas, I would put in tiptop shape. Easier to get parts here, you know all the suppliers, and who wants to spend time doing repairs when one could be driving.