Uh-oh, How Bad is it Really?

[Apodman]

1978 280E - M110 engine w/ K-Jetronic CIS -57,000 miles

I just put new injectors in my 280E and all seemed swell. Within days, I noticed liquid dripping from the front lip of the oil pan. Not oil, not gas, seems to be diluted coolant. I had topped up my radiator with water after a couple of long hot drives in July. Now on a hot day, the temp gage goes well over 200 degress F letting me know that my coolant level is low again. How low? It will take about 3/4 of a gallon of water to top it up.

I don't think the replacing-of-injectors has anything to do with the leaking coolant. I suspect that my water pump gasket (25 + years old)has abandoned its duty. Given the amount of water needed to top-up, my guess is that it is draining down only to the level of the pump.

So why does a gasket pressed between lots of steel spring a leak? What does this really mean? I have taken notes from threads on removing the water pump, and that seems managable. I plan to replace the gasket over Labor Day Weekend.

Any thoughts on why this leak occured? Any similar experiences? Any suggestions about what else should be done when the water pump is off?

[Mark DiSilvestro]

I think, on the M110 engine, you have to remove the crankshaft balancer to get to the bottom waterpump bolt.
For the trouble you'll go through to replace the gasket, better replace the waterpump too. It's probably what's leaking anyway.

Happy Motoring, Mark

[ctaylor738]

Yup. Almost certainly the shaft seal.

[mzsmbs]

new water pump, and anything else while you are there. I'd say new thermostat, check your hoses, do a flush...winter is coming.. maybe new belts...