external temperature

[ZiggyPA]

It seems the engine of my 91 PA takes a bit too long to heat up because it immediately begins to warm the compartment. According to the owners manual, I must activate the climate control and then select 'ext. temperature' to turn off the heated air (and as such, not use the heater core during warm up)
How long would it take before unheated air actually can be felt coming out of the vents?
I don't think this works, how could I check or fix this?
Also as I understand it it isn't possible to use unheated air with the climate control off since the owners manual states it will still try to heat the car (without using the fan)?

[imidazol97]

Originally Posted by ZiggyPA

It seems the engine of my 91 PA takes a bit too long to heat up because it immediately begins to warm the compartment. According to the owners manual, I must activate the climate control and then select 'ext. temperature' to turn off the heated air (and as such, not use the heater core during warm up)
How long would it take before unheated air actually can be felt coming out of the vents?
)?

I don't think there's a coolant shutoff valve in the system like some older cars. What you are saying is that the motor warms up slowly. I would suspect the thermostat is not closing completely. Replacing with a new one or taking the old one out and checking it might help the motor to warm up faster. One check would be when the heater is just blowing warmed air, see if the upper radiator hose is warm. The thermostat should not be letting hot coolant out of the motor to the radiator when the motor is partly warmed up. The hose may get warm near the thermostat, but shouldn't be warm all the way to the radiator until the motor is up to near full temp on the gauge. That would make me replace the thermostat.

The heater will get warm from the warm water circulating through it. If you keep the blower motor speed at the lowest setting, more heat will stay in the heater core; but I'd just use a lower speed and get the inside warming up.

You might see if the heater is partly stopped up. With the motor warmed and the blower speed on high, both heater hoses should be the same temp; if one is noticeably cooler than the other, the heater may not have enough water flowing through it.

If you're saying the temp gauge just takes too long, check the thermostat.

[ZiggyPA]

First I also suspected the thermostat. But when I noticed the climate control was warming up the air while turned off when the engine was still cold, I figured this had to be the problem. Yesterday I fiddled with the controls, the 'ext. temp' button does not function but when I set the system on the lowest temperature it does shut off the heater core and uses cold air.
When I then turn off the climate control, it doesn't heat or use the blower. Now the engine warms up quickly !