2001 Montana - Heater problem

Hi all,

I'm new to this forum and hopefully i can find someone who can help me with this problem.

In the morning, when i start and warm up my van, i only get cold air even though the temp gauge indicate normal. When the van is in motion, warm air start to coming out but as soon as i stop to a red light, it start cooling down.

Sometime, the temp gauge indicate that the temperature is a bit over the normal, and then come back to below normal. No overheating. So it can't be the thermostat.

I do to have to refill frequently the coolant tank. No sign of coolant leak on the soil or anywhere on the engine. As soon as i add coolant, the temperature(heat) work as normal.

What do you guys think the problem may be?

Many thanks!

You say you are refilling the coolant reservoir frequently. How much and how often?

You'll have to locate where the coolant is going.

Have the intake manifold gaskets been replaced?

"As soon as I add coolant, the heat works". There's the problem.

Like I said, find the leak.