MGB-GT Help:'70 MGB-GT running hot

[Steve P.]

I'm stumped and I'd like to draw on the experiences of folks here.

My MGB-GT is running hot and I have had no luck finding out why. It runs great (engine rebuilt within the last 5K miles), but it heats up fast (reaching 180 degrees within a mile of home), and the temp continues to creep up. I've never allowed it to overheat but its come close. Here's what I've tried so far;
* removed and flushed the radiator, no crud in coolant or radiator
* checked timing (static, mechanical and vaccuum advance):OK
* checked hoses for collapsing or blocks
* has good compression, no water in oil or bubbles in radiator (head gasket is OK)

Today I replaced the original 180 degree thermostat (its OK) with a 160, and it has the same problem. Just takes a little longer for the temp to rise.

 

[Bruce74B]

Gee, I had the exact same thing this spring...right before my water pump failed...but yours sounds like it has been going on for a while. Just my best guess.

Bruce

 

[19MGA60]

is water disappearing?? How about the gauge, maybe it isn't reading correctly? I am with Bruce if the above is correct, go with the water pump. Not a hard job and won't hurt even if it doesn't solve the problem.
tom

 

[8NFord]

I have noticed there is a fan shroud in the Moss catalogue. Also there seems to be a couple of lower air deflectors both in front and behind the radiator, depending on the age of the car.

 

[timbomath]

Just an outside chance- but it cured a similar problem on a marginally overheating Mustang once for me- is your coolant too rich with anti-freeze? Shouldn't be more than 50/50, experiment once with straight distilled water with maybe a pump-lube additive. Problem almost sounds like it could be a blocked cooling journal somewhere in the engine. LOL
Tim Matheis