Hello,

How much overheating can a 740 engine stand? I had water pump failure in the middle of Atlanta. I didn't notice the gauge until it was all the way in the red zone. I turned the engine off immediately, got a tow, and haven't had the courage to try to start it since. What are the chances I've escaped without causing major damage?

Thanks,

Pat McHenry

My wife was driving my 744 when the heater hose under the intake manifold popped. She drove it home, a couple of miles, it was a dark and COLD night. Our daughter ran into the house yelling the car was smoking. I went out and could smell the antifreeze.

I fully expected to see the head melted on top of the block with the head bolts sticking up. The next day I replaced the hoses, added fluid and drove it. That was in 1994 and it now had 256K miles on it. The engine has a slight knock when cold, but what high mileage B230F* doesn't. I have never pulled the head, the engine pulls very strongly and always starts.

Don't sweat it. These are are very tuff engines. I couldn't do that with my 965 and it's all aluminum engine.

Have to agree with the posts below. I had a pump go out 2 months ago, and didn't notice until I was pretty hot. I filled up the resivor with water and drove 15 miles back home and replaced the pump. A week later, my radiator cracked around a transmission cooler line. This time I didn't notice until the indicator was in the red. This one scared me because I immediately turned the heater on and there was no heat. I felt better when I found the leak, but still felt like my head gasket may be finished. I repaired the radiator and have had no problems for the past 2 months. Hopefully your head is ok. Just trying to give you a success story to impart some degree of hope. I am impressed with the resiliance of my brick.

Usually damage is noted by poor engine running while it is overheating and the red paint at top of block where head meets block turns brown.

The coolant sensor will melt and usually set a fault code w/check engine light also.

Rapid, total loos of coolant from a busted hose or radiator are the things that kill an engine quickly. Leakage that isn't so total and leaves some water in block usually doesn't do severe damage.

Fill with water and start engine and see if the pressure in coolant system rises almost instantly. This would signal blown head gasket (not a thorough determinant of a bad head gasket, but will tell if it's real bad news).

Pat,

Have the car towed to a shop that you trust. They will be able to assess whether the engine sustained any major damage. It is possible that you blew the headgasket or warped the head, but this is not always the case. If you're lucky, and you didn't run the engine any longer than absolutely possible after it overheated, you might just get away with a new waterpump. But best to have it checked in any circumstance. Starting it right now would probably not be a good idea. ;-)