Poor heating

[dreja]

Hi,

I've driven my car for 2 weeks now, and I've noticed some problems which I have to clear...

The first of them is poor heating in the driver's compartment. The temperature indicator rises at about half the scale after 2 or 3 km of driving, but the air flowing through the heating holes in the cabin is not hot as it should be.

I've checked the valve (located at firewall in the engine bay), which opens the water flow to the heater - it seems to work ok, as it moves smothly.

If there was a faulty thermostat, will the temperature gauge still rise normally ?
Btw. when the hating at my father's Honda didn't work, also the temp. gauge didn't rise (the problem faulty thermostat), but my gauge rises normally.

Regards
Andrej

[Euripides]

The valve sometimes seems OK but it's not really working. It can be completelly stuck, or moving smoothly, but the valve remains steady. It happened to me (and still not fixxed).
If the thermostat was bad, the temp would not rise normally, especially these cold winter days.

[SutteR]

My heat is poor too...
The engine temp gauge moves up to a max of 1/3 but the engine seems to be warm, i mean operational temperature. Can be the water temp gauge which is wrong, or more likely the thermostat?

[Ivan141]

SutteR, in your case I would suspect the thermostat. In dreja's case I would suggest to try and bleed the cooling system of air. Run the engine with the radiator cap off for a while, making sure that the heater valve is opened (heat turned all the way up). Maybe some air is caught in there..

[SutteR]

Sorry, I actually tried to steal your topic, dreja...
How would you make sure that the temp gauge or the temp sensor is working perfectly? Since a thermostat is an expensive part here...

[dreja]

Ivan, shall I run the car without radiator cap in cold state ?

What about the pressure? Won't the water blow out of the radiator with the car running (through the opened cap hole)?

Are there any other bleeding holes in the system?

Regards
Andrej

[Ivan141]

Yeah, run it until the thermostat opens (probably pointless if the thermostat is closed, cause it wont be using the radiator until it opens). As long as you run it opened from somewhat cold condition it wont build up pressure and you wont have a fountain on your hands..
I'm not sure if it will help but I've often read posts on club4ag about people with similar problems that had air stuck in the system somewhere. Do a search there as well...might turn up some usefull info. I dont know of any other bleeding locations on the 4age BTW.

[dreja]

Today I have completly flushed all the coolant out.
Then I've also washed the system, including heater radiator with pressurised water and there were no obstacles.

I've also checked the heating valve (the valve that opens the flow through heater) and it works ok.

Then I dismanted the thermostat (thanks to ZaX for the info about it location ) , and it seems it works ok. When I put it in cold water, both "caps" moved in the way shown on the picture...

I don't have any idea, what else could be wrong, because the heating is very poor, although there wasn't any air in the system...

Regards
Andrej

[ZaX]

Search hachiroku.net.
There used to be good topic about heating in ae86 since it's cold there too.

[dreja]

I have checked the blend door and it seems it works ok. Here are the pictures:
Door opened:
http://www.mobisux.com/album/data/500/8196opened.jpg

Door closed:
http://www.mobisux.com/album/data/500/8196closed.jpg


I have also checked the working of the thermostat. I've found out that it starts opening at 72 degrees Celsius and completly closes at 69 degrees Celsius.
So I'm wondering what does the 82 degrees, written on thermostat mean. At the 82 start opening (small hole) or at 82 completly opened?

Regards
Andrej