Sounds like poor circulation to me. Maybe an air slug in the water pump, or just a bad pump. When was the last time you checked the coolant level? Low coolant will also cause this set of symptoms, but there are usually others to go with them, too. Does the light blink in the temp gage when you first turn the key? If it doesn't, there is a problem!
Low engine speeds mean low water pump speeds, and that is when a weak pump will be most noticed. Go back to the engine, and try to move the pulley and belt for the pump. If you have been very good, and lived a good life, you have a loose belt. The pulley should not wobble. If it does, the earing is gone, and the pump impeller will not be in the right place any more. That means low pumping effeciency. Hope for low coolant levels! That is easiest and cheapest to fix. THe re may be another problem, tho - where did the coolant go?

Germain <reglys@SYMPATICO.CA> wrote:
Hi Volks

Last day I was using my Westy to go to work. Traffic jam is frequent ( I
have to cross bridge) on my way to work and I was experimenting some engine
overheating (Temp. gauge was reading a bit higher than 3/4 of the full span)
in spite the fact the outside temperature was around 45F.

Every thing was OK for the first miles. After the engine warm up period, I
was feeling the good heat coming from my front heater. Hovewer after a while
I noticed the heat coming from the front heater was cool and the
temperature gauge was reading high. The overheating and no heat from the
Front heater problem was happening when the engine was idling. As soon as
the engine is working at normal speed everything is OK.

Thank you for reading me. Any advice on what could be wrong?

Germain

Evan Mac Donald

1984 Wolfburg
1985 GL 7 Pass.
1991 Carat Weekender
1972 Chevy P/U
1993 Bonneville