I need to cool my Baby down.

[Phireman]

After a 27-year hiatus I’ve recently acquired another MG Midget. It’s a ’77 with 57,000 showing on the odometer, who knows how accurate that is… Before buying the car I drove it in and around town on city streets and expressways for about 45 minutes then let it sit at idle for 5 minutes to check it out. Weather was good and hot, no problems were evident. I felt fairly confident with the engine and drive train. The rest of the car is in very good condition. It is an LBC so I expected some issues just not quite so soon.

My question to the board today is where to begin with an overheating problem. She got hot when I drove her to work today and was boiling over. Coolant was leaking out as if through a sieve. No cracks in the hoses I could see. Appears as if coming out of the overflow.

My gut instinct is to pull the radiator, have it serviced; replace the water pump and thermostat then see how she runs.

Is this a good starting point or should I look elsewhere first?

 

[regularman]

I would pull the radiator as well. Did you try turning the heater on to add a little more cooling until you work on it. It helps some. I would also check the oil cooler if you have one and they also make a heate transfer fluid called "water wetter" that works good too. Just don't overheat it so bad that you crack the rings or soemthing.

 

[Thor]

I had a major overheating problem last year with my 1500 but the steps to figuring out the cause to an overheating problem should be the same:

I would start with the easiest causes to fix first.
1.Did you have enough coolant in the system when you first started out and did you have a good coolant to water ratio?
2. Next I checked out the radiator cap. As they get old they sometimes don't hold the pressure thus leading to overheating.
3.Do you have the correct thermostat in and is it working. You can check whether or not the thermostat functions by removing it and placing it in some boiling water. If it works you should see the spring/value move.
4.Flush the cooling system well to see if you have sediment, etc blocking it. You can take it to the professionals to get it really flushed out well I hear. I just used a garden hose.
5. I wonder if your engine is running lean as this will contribute to overheating. You could try retarding and advancing the timing to see if that helps.
6.Next you might think about the water pump as a factor.
7.Finally I realized my clutch fan was malfunctioning but this should not be a cause on the 1275 since it has a clutchless fan system.

I probably have missed some but am sure others will contribute many other good suggestions. Best of luck to you.

 

[Morris]

Do a compression test. Overheating is frequently caused by a bad head gasket.

 

[lesingepsycho]

I agree with Thor's list. Start with the most obvious; overheating is generally (at least in my experience) caused by an inadequate amount of coolant. These tiny spridget engines really need a very high coolant/water ratio. Since you say the water is coming from the over flow, I would definitely suspect that.

JACK

 

[Taz]

some people overfill there system too. remember there has to be room for the fluid to expand when it gets hot. If there is to much fuild it will come out the overflow

 

[regularman]

Does it tend to overheat on the highway or just around town?

 

[Phireman]

Thanks, folks, for all of your responses.

I tried the easy fix first and replaced the thermostat. AutoZone actually had one in stock. Filled the coolant system and drove around just enough to get her thoroughly warmed up. So far so good. Too early to tell if I warped the head but I didn’t smell any antifreeze odor on the dipstick. I might give her an oil change this weekend to check and just for good measure. I’ll top off the cooling system tomorrow and give her a good run around town, (staying close to the house of course).

It is great to be behind the wheel of an LBC once again.

 

[jlaird]

If you got coolent in the oil you will know it by sight, oil turns whiteish and nasty.