jim010

I have a 1999 Carrera 4 tiptronic.

Bought it in December and the heat did not work, although it was happy to blow cold air. The tech guys at the dealership checked the temp of the hoses and they were at 40 Celsius and the temp out the vents was good when they had it, but after picking it up, it didn't work again. The figured teh radiator was clogged. I bought one and installed it myself (PITA) and got warm air out of it, but took a long time (15 min driving) to get it. This morning the drive to work it was getting warmish by the time I got to work.

This is just not acceptable. Is there anything else I should be looking at to get heat in the car? Tech guy said they checked the blend doors and they all worked, but I have not visually checked that yet for myself.

DBJoe996

Hmmm...since you are in Canada, I figure the ambient air temperature is pretty low. And 15 minutes of driving is not enough time. Even here in sunny Florida, on a 60 degree day it will take more than 20 minutes of run time to reach operating temperature, enough to blow warm air in the cabin. Maybe take the car for a longer drive and see if warms up. And by radiator, you mean the heater core? Very difficult to burp all the air out of the system after doing that. I assume you followed the specific directions for burping the coolant system. Also, in case you are inclined to start it up and let it idle until it gets warm, that is not recommended and is not a good idea..

Cosmo Kramer

Mine warms up quickly in the cold weather. What temp is your gauge showing? Maybe your thermostat is stuck open .

40 deg c pipe temp won't put any heat in the cabin .

jim010

Someone suggested the thermostat to me as well.

Ambient temp today is around 0 Celsius, and the heat still sucks. Engine temp on the gauge is 60 - 70 Celsius but didn't get up there until I got to work, really. Same with yesterday after I switched out the radiator and drove around. I did get some nice warm heat after 30 min of drivng, but not hot. Temp gauge was around 80 and outside temp was around 0 as well.

To get the thermostat I have to remove the waterpump, correct? ... I really don't feel like doing that ...

jim010

So thermostat is the next one to look at to get heat again? Is there a way to see if it is stuck?

RngTrtl

i driven with temps a little below 0C and the car heats up fairly quickly and the heat is working fairly good in 5 mins and is hot as hell in 10.

jim010

OK, so something is messed up.

RngTrtl

definitely. It takes me about 5 mins to get the interstate and the air is warm. 5 more mins after i get on said interstate (doing 70-75ish) and the air it hot.

DBJoe996

Thermostat is under it's own separate cover attached to the engine block. You do not need to remove the water pump. If it is stuck open, then too much coolant flows to warm up properly. If it is stuck closed, no coolant flow, but that should be apparent because the engine would get very hot quickly. There is no way to check it unless you remove it, and if you do that you might as well replace it. You will also need at least a gallon of Porsche antifreeze to mix and refill the coolant system. Due to the location of the thermostat housing and thermostat, you will lose almost all the coolant in the engine when you remove the housing hose (unless your coolant mix is fairly new I would recommend draining and replacing as opposed to using the coolant drain plug to drain the coolant and re-using it). Here is what you are looking for http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=996-99-05&section=105-00

Behle

From my experience , if the thermostat is stuck open , you will likely see the Temp Gauge never go past 1/4 of the display. No matter how long you drive.

jim010

OK. Mine almost reaches 80 Celcius - probably 70 max after driving around 30 min.

DBJoe996

Something is wrong. 70 degrees celsius is only 158 degress fahrenheit. Should be more like 82 celsius. I think your thermostat is stuck or someone put in a low temperature thermostat, and with the low ambient temperatures, the engine does not warm up completely to produce much heat. I have a 180 degree thermostat and on a cool day it will pump out heat enough to cook something.

jim010

Is there a way to confirm if it is stuck open?

DBJoe996

Nope and yes....pull it out and put it in a pan filled with water and a thermometer on the stove, heat it up to 180 to see if it fully opens. But since you have it out, replace it and forget testing it. They can go bad.
Recommend this and some reading https://lnengineering.com/products/o...e-install.html

jim010

Sigh ...

As I don't know what else it can be, then I will have to replace it - unless someone knows of something else I can check?