heat on cool night

[roadboy]

I'v had my car for 6 weeks now and am having the time of my life. Other than small problems(that the fact file has been helpful with), the car runs good and strong. My question is, the other day I took the car out on a cool night with the roof out to relax, and because it was cooler than I thought I needed the heat on for the first time. What i found was that it took nearly 20 mins of spirited driving to get any heat at all and even then it was only warm and not hot. While cruising at nearly a snails pace on the local strip, I noticed the water temp climb to nearly 100 deg. After grtting moving again dropped back to normal between 80-90. I checked coolant level the next day and everything seems good. Could it be thermostat? Any ideas? Not critical but would like heat as I love driving toppless.

Thanks
Brad
89SE

[techspy]

I had heat issues as well. By this I mean I couldn't get much heat to come out of the vent no matter what setting it was in. I found that my vacuum pump was bad and that in turn was not moving the doors in the dash that route heat over the a/c coils or the heater coil. By default with no vacuum it routes the air over the a/c coils and not the heater coil. I have a 94 S4 which has an electric pump (gm) in the rear boot just over the passenger wheel hump. After replacing that all works like it should. I found that this was the problem by opening the front boot and watching the door that lets fresh air in. Then I moved the a/c controls to various positions to see if the door changed. Do this with the engine running. If it doesnt move at some point, it is a vacuum issue. I also had the same prob with my 83 Turbo that I used to have. It was a mechanical pump and the problem was simply a disconnected vacuum line under the dash that came loose. I am not sure if your 89 has an elect or mech pump though. As for the temp being around 100, that does seem a little bit high, but unrelated to your other issue. For that I would check all your fans and water/antifreeze levels. I also use Redline Waterwetter cooling system additive. It really helps keep the temps down.
Hope this helps.

John
94 S4
http://hometown.aol.com/oneshotcop/myhomepage/profile.html

>> Edited by techspy on Thursday 1st July 06:46

[Dr.Hess]

On the 100C temp, I would also suggest you thoroughly clean out the radiator. Mine did the same thing, and I got under the car with a garden nozzle on the water hose and a liquid sprayer attachment for my air compressor and between the two of them blasted out the dirt from the radiator. Made all the world of difference.

Dr.Hess
89 non-SE

[roadboy]

Thanks for the insight. I am away for the weekend but will check both items when i get back and see if it solves problem.

Brad
89SE

[roadboy]

Thanks John, I believe you must be right, the door for the vent does not move at all. Found something under the wheel well(not sure if its the pump). Whats the best way of getting at it. Also rad fans dont seem to come on at all, no matter what the temp. Fuses are all good no warning lights. Would the relay be shot or the fan motor? Car still stays cool as long as its moving(which it does well). Sorry to sound like such an amateur, but this car has some weird issues. Wouldn't trade it for the world.

Thanks
Brad
89SE

PS: Anyone know good place for parts in western Canada.

>> Edited by roadboy on Monday 5th July 04:35