Has anyone actually had a broken or stuck thermostat? I'm wondering if I have one.

I just bought the car used a few weeks ago, a 2004 6SP with 5600 miles on it. The car takes forever to warm up, and my fuel economy kind of sucks (about 14 MPG mixed). Never seen 200 miles over 6 tanks before the light comes on. The car has the latest flash.

My drive to work goes like this:
Pull out of 60 degree garage
Drive down road, 45 degree outside temp
Wait 5 minutes / 2 miles before the needle starts to move
Wait 15 minutes / 6 miles before the heat really kicks in from the heater. Needle is now just over halfway to the middle (33%) and never moves from here.
Drive the last 2 miles on the highway with the heater finally turned down.

When I drive home, the heater never gets turned down since it never gets warm enough due to the colder starting temp, and I pull onto the highway less than a mile after I start and drive on it for about 2 miles. It's not like it's -20 out or anything. It's 40-50 here during the day. My old DSM used to be pretty warm at the end of the highway section.

If I drive it an extended distance (over 20 minutes), the heater really gets going, and I have to run it at less than 1/2 heat to make it comfortable. So I know it can get plenty warm, but it just takes forever.

I also get a gurgling noise out of the heater core when I start the car. I've checked, and it has plenty of coolant, right up to "full".

I've searched around and didn't find a situation similar to mine. Does anyone else have a car that takes forever to heat up or is it just me? I read about some people that let it idle until it gets warm, but that would take 30 minutes in my car!

Final question: Where the heck is the thermostat in our cars? I may just try replacing it.

 

The gurgling suggests that there is air in the coolant system. Take it to a dealer and have them bleed the air out of the lines. That could contribute to your slow warm up, but your warm up times seem reasonable to me if your "wait 5 minutes" means you are moving during that time. (If idling for 5 minutes, the needle in the temp gauge should be at, or close to, it's ~midway parking position by then.) I doubt that you have a thermostat problem. I can't recall anyone having such a problem, but you should do a search for "thermostat" to see for yourself.

In fact, the search function should be the first thing you do when you have a question. There is a wealth of information on the forum on just about any topic you can imagine.

 

Gord from Calgary had a similar problem, in this thread -

Link to thermostat problem

....maybe send him a PM, ask how it went.

S

 

I had an issue where I never got hot air out of my vents, and it was an air bubble in the coolant lines. A simple bleed and refill fixed it right up.

 

Why does the Renesis warm up slower when it's producing power? I'm used to engines warming up quicker when they are being used rather than just idling. I guess I've never just let it idle up to temp - I always assumed that because it took so long while driving that it would take much longer while idling, like all my other cars have.

I did search all over. The whole reason I asked this question was because I DIDN'T see anyone that had encountered the same problems. The only thread that dealt with this at all was posted yesterday and I did my in-depth search over the weekend.

 

You have to realize that the cold air is hitting those oil coolers too, that keeps the oil colder longer while moving, less movement, less air going across the coolers. Same with the radiator. That would be why I think it take longer moving, could be wrong though.

 

Supposedly, the oil coolers are thermostatically controlled as well, so they shouldn't be operational until the car is warm.

 

Really, did not know this. Thanks.

 

Air bubble hypothesis may pan out something for you but over two engines and 60,000 miles my RX-8 interior heating profile is exactly the same as what your describing, so I'll put my vote in that what your experiencing in normal. Thank God the seat heaters warm up quickly on sub-zero days here in NH!!!

 

I checked the parts manual diagrams but didn't see any indication of a thermostat controlling the oil flow through the coolers. The main cooler lines connect to the engine at the oil filter body and the front cover, and there is no thermostat indicated anywhere in this system. Of course, the coolers themselves could have internal thermostats but I doubt it.

 

They have thermostatically controlled/anti drain valves in them

Had them apart when I added the 3rd oil cooler for the track....and to drain the oil for the change to syn...

 

Interesting. Thanks!

 

They've always had them. They used to be externally mounted up to 71 or something and then they went to an internal thermostat. It's the type of thing you don't want failing on you. As for the water thermostat, it is located in your upper water outlet and could possibly be the culprit. Your figures are not too unusual though.
Paul.