White crusty material on water pump and thermostat neck

[Lawrence S.]

Guys,

Is there a chemical reaction that causes the dried salt looking material that is sometimes found around a water pump or thermostat neck? It looks like effervescent? This is not going on in my car but a friends car and he has flushed his radiator several times with the no luck in getting rid of this stuff. I have not had this problem before. Thanks for any suggestions.

[John F.]

Re: White crusty material on water pump and thermostat neck

Probably the minerals in the water mixed with the anti-freeze. I always use distilled water with anti-freeze.

[Bill M.]

Re: White crusty material on water pump and thermostat neck

Is the intake aluminum? Is it eroding inside the thermostat housing? This could be electrolysis a short in the system and eats away at the meeting point of 2 dissimilar metals.

[Kenneth B.]

Re: White crusty material on water pump and thermostat neck

Probably the minerals in the water mixed with the anti-freeze. I always use distilled water with anti-freeze.

I agree is probably calcium from hard water. Try a toilet bowl cleaner or calcium cleaner.

[Duke W.]

Re: White crusty material on water pump and thermostat neck

It's minor seepage from the gaskets or coolant pump seal if you see such deposits at the weep hole. The glycol/water evaporates and leaves traces of the inorganic salts that are part of the corrosion inhibitor package in both IAT (green) and HOAT (Zerex G-05) type antifreezes. OAT antifreezes like Dexcool do not leave such deposits because they contain no inorganic salts, but the orange dye usually leaves a stain.

New gaskets with a good gasket sealer or a new pump seal will eliminate the problem. Gaskets/seals don't last forever, and with gaskets it can be a clock time (like decades) rather than an operating time issue.

I don't recommend any chemical cleaners as they may leave stains on aluminum parts like manifolds. When the parts are off for new gaskets remove the deposits with light application of a small brass wire brush or toothbrush in a bucket of water with detergent.

It may be worth cleaning off the deposits on the car, and then adding Bar's Leaks. That might seal the deteriorated gaskets.

I also recommend use of a VERY thin film of silicone grease on the inside of coolant hoses where they meet nipples. This will help seal the connection, prevent electrolytic erosion of the hose (Those little craters you see inside old hoses at the connection point), and keep the hose from seizing, so it should be easy to remove in the future.

Duke

[Domenic T.]

Re: White crusty material on water pump and thermostat neck

Lawrence,
Just had that happen a few months ago after adding anti freeze. We think it was because we mixed 2 different kinds. It happened after the car sat for a Month or so.

Dom

[Lawrence S.]

Re: White crusty material on water pump and thermostat neck

Guys,

Thanks so much for the help on this. I believe we will be able to troubleshoot my buddies car with this input.

Lawrence

[Lawrence S.]

Re: White crusty material on water pump and thermostat neck

Is the intake aluminum? Is it eroding inside the thermostat housing? This could be electrolysis a short in the system and eats away at the meeting point of 2 dissimilar metals.

Intake is cast iron