QuestionI just got my 1977 MGB out of storage (4 years). Started right-up. After 5 minutes, I shut down to check things out. When I removed the cap on the valve cover, smoke (quite a bit) was coming out. Radiator hoses were also very hot, but heat guage showed cool. Any ideas?
AnswerHi Norm. First a question - did you check the water level in the radiator? It could be nothing more than an air bubble preventing circulation. Take the plastic bung out of the top of the elbow and make sure it is topped up to the brim. Replace the bung, then remove the cap from the expansion tank and make sure that the tank is half full, not full to the brim.
If the engine overheats quickly but the gauge stays cool, it could be that the thermostat is stuck shut. You can check by feeling the temperature of the metal pipe where the top radiator hose enters the radiator.
The thermostat lives underneath the water elbow at the front of the engine. Remove the top radiator hose, undo the 3 bolts, and remove it. New ones cost pennies, so fit a new one - with a new gasket.
Do not be tempted to run without a thermostat, because the MGB has a bypass hose. so it would significantly reduce the circulation and the car would continue to overheat.
If that doesn't do the trick, you have a more obscure problem, possibly a frozen water pump impeller, so the water is not encouraged to circulate. The whole system is very basic, so you should be able to find it and fix it.
