Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

I have a 1995 1.5 non turbo diesel. The heater is just getting warm. I've checked all obvious things but still can't find out why it won't get hot. The temperature of the car only gets to 85 degrees even on a motorway run. Could this be the problem or do they run at that temperature? There's no mayo in rocker cover.

might be an air lock

when the car is warm, take the coolant cap off very slowly and leave it off for 5 mins and then see if your heater gets warm