Overheating and water pump: Lessons Learned

Follow up.

The water pump shaft was loose, rattled when running, and it did leak but that was not the end. What happened was one problem lead to the discovery of another. The water pump was replaced with a good used pump from the spares collection. During the 1/4 mile test drive the car heated very quicky close to H. The cap was removed from the radiator and there was no coolant flow. The initial overheating problem was with the thermostat not the waterpump. The themostat failed and was closed. The thermostat was replaced with a the new fail safe type. So the story goes, one thing leads to another. :)


Lee Wrote:

Slightly confused by the thread presentation so forgive me if I am repeating something.

Loose shafts usually, but not always, result in immediate leaks. I have seen pumps on several makes of cars that could not possibly be retaining fluid under pressure because they were so sloppy, but they were! Sometimes pumps weep through the vent under the chin of the housing and the shafts are still perfectly steady. Go figure!

With the thermostat replacment you probably have not overdone anything though. Lots of times, if the systems overheats for what ever reason the 'stat is damaged and needs replacement. In fact I would say that if any significant heating occurs, that is to the point of fluid lose or more, the thermostat should be replace as a matter of prevention.

Jack

Just for giggles, I have also seen an instance where the impeller, held on to the shaft by a simple roll pin that rotted thru, came loose, and altho the shaft was somewhat loose, there was no leakage and no obvious malfunction visible or audible at the pump. However, this was on a different make of car, but there are often several reasons for overheating beyond the obvious.