[coopp]

I'm quite suspicious about the coolant system in my '82 Spider. I've scoured the blog, and got several good tips, but I've not yet resolved this. Here's what I'm facing:
After a good long ride, the gauge hardly budges off 110F. There's no heat from the heater, and the upper rad hose is warm, but not hot,as I would expect. I've bled the system a couple of times, and confirmed the gauge is working by grounding the wire. No leaks that I can find.
I'm thinking the t-stat may be stuck. But if stuck closed, wouldn't that give me lots of heat and a high temp reading, being that the coolant isn't going through the rad? If stuck open, I would expect a slow rise, but the upper hose should be pretty hot,right?
Open to suggestions. Thanks....and Happy New Year!!

 

[Norseman50]

What if the thermostat were stuck open, or if it was missing completely? Wouldn't that produce the symptoms you are seeing?

 

[ghnl]

You are describing a stuck open (or missing) thermostat. The system (including the upper hose) never get shot because it is always being cooled - over-cooled actually.

Some thermostats are designed to fail 'open'. Especially if it has ever over-heated.

 

[coopp]

Ok, I'll drain the system a bit, pull the thermostat cover and see what I have. But isn't the upper hose the feed to the rad from the engine, so it should be hot, right? (the lower hose being the cooled returned to the engine, per page 07-2 in the manual)? Or am I missing something?

 

[ghnl]

But with the T-stat stuck open (or missing) the engine never warms up so the upper hose never gets hot.

 

[Lokki]

I'd just order a new thermostat and replace the one you have. They're cheap enough, and -since it seems pretty likely to be the problem -why take things apart twice or have the car down waiting on parts? For that matter, if you don't know the last time your coolant was changed or how old your radiator hoses are, this is a good time to do them too.

 

[coopp]

Yup, I did exactly that. Will be replacing it this week. Thanks guys.