I had an independent mechanic - not part of a shop - install a thermostat for me. I had it shipped to him and he put it in. Or so he says. After having head gasket work done (by the mechanic), replacing the water pump (myself), and replacing the reservoir cap (myself), I am still having overheating problems. So I returned to the thermostat.

When I pulled it out, I was surprised at how dirty and worn the housing looked for a new thermostat. The car has only been driven a total of 550 miles since it was put in. All short local trips.

Does this look to anybody else like a very OLD thermostat, and therefore like a total rip off?

I asked the mechanic and he said he replaced it, dropping it the whole new unit as is (so it's not that the housing is old and the thermostat inside is new).

I then tested the thermostat by boiling it beyond 200 degrees. I understand it's supposed to pop open if it's functioning correctly. It's hard to tell for sure since it's all one unit, but I certainly didn't notice or hear any kind of popping. There were a few large air bubbles that came out between 185 and 200 degrees, but that was it.

Does that further compound that this is an old, and most importantly BROKEN, thermostat?

Just looking for some experienced opinion on what these things look like after a while before "discussing" this further with the mechanic. I've literally never even looked at an auto thermostat before prior to pulling this one out.

Thanks for your guesses!

Dan

 

An additional question about Disco II thermostats ... I'm trying to run some sealant through the cooling system. The instructions say to take out the thermostat and then reattach all the hoses.

Is the house on the Disco II thermostat supposed to come apart somehow? From what I read, you can typically take out the thermostat itself, and then presumably reattach the hoses to an empty thermostat housing and let the sealant flow through that way.

How do you do this on a Disco II when you apparently have to remove the entire thermostat housing and end up with three primary coolant hoses going nowhere (all the hoses that normally attach to the thermostat housing)??

 

You cannot run the DII without the t-stat unless you make a bypass pipe of some kind.
You can take a screw driver and break out the guts and make it wide open.
That t-stat looks old to me.
The DII t-stat works on PSI, it is very complicated and way to troublesome if you ask me.
In the write up section is a thread on how to make the DII cooling system more traditional, like that of a DI and alot more reliable, like that of a DI.

 

Thanks Spike.

On further reading, it sounds like boiling a thermostat makes it pop in a very obvious way. Not subtle at all. In this case, my thermostat most definitely did not pop open, and my mechanic has either screwed me over or is, at best, inept and forgot to put the part in.

I ordered a new t-stat from roverparts.com. $20 there vs. $89 at AutoZone (wow). I'll use the old one as a junction, and see if I can break out the innards some.

Kind of sucks that it's all one unit.

Dan