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MG MGB Technical - Hi Temp in Traffic

Hi,
I was driving in heavy traffic downtown sunday it was a warm but not Hot day, no more hot days left here in Ottawa,. In stop and go driving the temperature reached, but not in, the red mark on the guage. I turned on the heater which helped keep it from going into the Red. The next day I checked the coolent level it was fine. There were no leaks and the electric fan works fine, checked that while it was hot, The radiator fins are not plugged. Normally this engine runs a little cool and it cooled down when I got out of the heavy city traffic. I am planning on driving this car 1300KM next week. Any Suggestions besides stay home :-)
Cec

Cec,
Make sure your fanbelt is tight enough to drive the waterpump properly. Also, you should pull out your thermostat, put it in a pan of water on the stove, and use a suitable thermometer to check to see if and when it's opening.
Joe
Joe Ullman

Cec, make sure your shroud from the front valence to the bottom of the radiator is in place. In idling it is possible for the air which has just passed through the radiator to be sucked around and go through the radiator again. This will cause the car to heat up at a standstill, but cool down when the supply of cool air is restored when under way again.
Carl Holm

Perhaps a good radiator flushing would help. I did mine a while ago, and I was amazed at the amount of brown gunk that came out, before the water turned clean.

I used one of those Prestone kits that are sold at auto parts stores, K-Mart and just about everywhere else that has any kind of automotive stuff.

I put the tee fitting in the hose between the heater valve and the heater. You attach a garden hose to the tee, remove the radiator cap and turn the water on. Run it until the water becomes clear.

This helped my car. It was running warm when I was in slow moving traffic. Now it runs fine. The only other thing I did was replace the thermostat.
Paul Noble

I wonder how quickly this condition came on, as that might be a clue. Anyway, I thought it should be mentioned that overly retarded ignition timing can cause overheating to a surprising degree. This happened to me recently when readjusting the timing was not completed after installing a pertronix ignition.
David Cushman

To add to David's comment, overly advanced timing can affect heating as well, so can running a with too lean a mixture. I personally would have the radiator rodded and cleaned as a first step, it never hurts.
Bill
69 B-GT
Bill Mertz

As quickly as it appears to have come on and your previous experience with it, I would first check the actual temp of the water in the top tank while it is in this condition. If it is indeed THAT hot, then I would check the T-stat first and then, if that is OK, go on as per the rest of the guys recommendations.

IF, however, the top tank temp is really about normal, then suspect a faulty temp sender for the temp gauge or possibly the voltage regulator for the instruments. The latter will give you goofy gas gauge readings too. FWIW
Bob Muenchausen

My 72 B has shown HOT for the past 3 years whenever the outside temp is over 25 C or going up a hill. Since I live at the top of a long steep hill the guage is at max by the time I get home. I opened the rad cap (using an insulated mit) and stuck a meeat thermometer in it. It read 175deg F, so was not hot at all. It is likely the sender.
Bruce Stevenson

This thread was discussed between 18/10/2001 and 23/10/2001

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