proper thermostat for '85 300TD?
 

Hi all--
Can anyone tell me the proper thermostat temperature for an '85 300TD wagon?

When I bought me car I ordered a thermostat which, I believe, was 80 degrees. Didn't get around to putting it in right away, but when I had the car at the mechanic, I asked him to install it for me. He said, 'oh, your car really needs an 87 degree thermostat; I'll trade this one with you and put in the hotter thermostat.' So, I've been driving the car a long time with the 87 degree thermostat, and it's driving fine, but I was wondering:

1) Was he correct in putting in the hotter thermostat?

2) If not, is it damaging the engine to run a bit hotter?

3) Is there any advantage to running the car hotter.

TIA
Michael

If you lived where it was pretty chilly in the winter, I'd run the hotter one... since you're in CA, I'd run the 80°C unit.

Why, the thermostat setpoint has no effect on the time it takes the car to reach it's operating temperature.

It stays at a higher operating temperature... I didnt say how long it takes to get there.

Hotter is relative. 7 degrees C will not affect anything but provide a more efficient heater. 87 C is approx 195 F. so its well within normal range. The main concern with any engine regarding temperature is that it is stable. If it rises to 87 quickly and stabilizes there then the integrity of the cooling system is intact. An engine operates more efficiently at a higher stable temperature. Internal parts move easier so possibly better economy and a slight improvement in power. Most new cars stabilize at 200 to 215 degrees as mandated by emission requirements and produce less pollution because of it. So dont dwell on it.

you all make good points.

i think the factory stat was an 80, yes?

if so i would have that ready to install and do it when this one fails or if you start to have a problem with it overheating.

the only ill effect that i know of is at the higher temp you dont have as much heat sink available to soak up heat on a big hill. so you might have to slow down quicker than if you had the 80 installed.

not to worry.

tom w