QuestionI just bought a 1979 MGB. The engine is overheating after driving 30 min in traffic. The fan works intermittently. The thermostat is new. Radiator full. The previous owner had a new carb installed just in June. Few ideas to deal with this would appreciated.
AnswerHi Bob,
I thought I answered this but it must not have went through so here it is.
Whenever a car came to me in the shop with this complaint here is what I had to do.
1. First confirm that it is really overheating, (blowing out of the over flow and a thermometer in the radiator to confirm hot)
2. Test dye in the radiator to check for CO or sniff with CO equipment. (checking for leaking head gasket)
3. Check coolant flow (to see if impeller is loose on it's shaft or broken vains.
4. Test thermostat to see that it really does open at or within 20 deg of rating. New does not mean it works.
5. Confirm that lower hose is not collapsing.
6. Set timing and carb to specs. (Either can cause over heating.)
7. Check electric fans to come on at 200 deg and off when temp drops to 180 deg.
8. If all this is correct, send radiator to radiator shop to have it flow tested and cleaned if necessary.
Howard
