Brock_from_WI
Veteran Member
I have had the TDI heater for 3+ years now. Anyway I use it a lot and just towards the end of last winter sometimes I would notice the coolant only about 100F after the heater being on 2 hours. This fall it is doing this more and more often. Right now we have been in the 15-25F range
So I checked the heater still pulling a nice 915w, left the meter on all night to find it only used .5kw in 2.5 hours, so it is obviously cycling on and off and the coolant was only about 100F again. If the car is at all warm the coolant heater will keep the coolant right up at 190F.
So my guess is one of two things and I would like your opinions.
First the over temp or regulator on the heater is failing and it shuts off before it should, causing the coolant to not circulate around the engine, but this seems odd because if the coolant starts warm the heater will keep it warm.
Second, for some reason the coolant isn't circulating like it used to. This would cause the coolant right near the heater to warm up and then the heater would shut off without circulating it around the engine. What might cause this? A bad thermostat? Thoughts?
So I checked the heater still pulling a nice 915w, left the meter on all night to find it only used .5kw in 2.5 hours, so it is obviously cycling on and off and the coolant was only about 100F again. If the car is at all warm the coolant heater will keep the coolant right up at 190F.
So my guess is one of two things and I would like your opinions.
First the over temp or regulator on the heater is failing and it shuts off before it should, causing the coolant to not circulate around the engine, but this seems odd because if the coolant starts warm the heater will keep it warm.
Second, for some reason the coolant isn't circulating like it used to. This would cause the coolant right near the heater to warm up and then the heater would shut off without circulating it around the engine. What might cause this? A bad thermostat? Thoughts?