Rust in motor

[Bob W.]

Started my 58 after sitting for 18+ years, didn't want to take any chances with old hoses I started to remove them and the thermostat. There is a lot of rust everywhere the hoses attached (caked up rust) so I don't know what the inside of the engine looks like but can only imagine. I soaked the thermostat housing in vinegar for two days and the rust is all gone. Would I be able to put vinegar in the cooling system and do the same thing? I have a rebuilt water pump (old one still on the car). Would I be able to connect the radiator hoses together and loop the heater hose and get the same result or would that do damage to the motor. If this is possible what would be the best way to flush the motor after?

[John F.]

Re: Rust in motor

My car was sitting for 20 years. Pull the thermostat, then pulled the plugs on both sides of the block. Use a good 6 pt socket on the drain plugs to loosen. Run a hose thru the thermostat opening with the plugs out and use a piece of a clothes hangar to run up the holes and dislodge what you can. Refill with water, button up, and run up to operating temp again and repeat. Water should be running clear out of the plugs.Replace hoses as needed. Refill with distilled water and anti freeze at 50/50 mix with new thermostsat.Should be good to go.

[Troy P.]

Re: Rust in motor

First time I ever pulled those plugs in an engine rebuild process the water jacket behind them was still full of core sand from the foundry. Had to wash and blow all that out. So If you don't hit water in the jacket you may find sand before you get to the rust.

[Dick W.]

Re: Rust in motor

Started my 58 after sitting for 18+ years, didn't want to take any chances with old hoses I started to remove them and the thermostat. There is a lot of rust everywhere the hoses attached (caked up rust) so I don't know what the inside of the engine looks like but can only imagine. I soaked the thermostat housing in vinegar for two days and the rust is all gone. Would I be able to put vinegar in the cooling system and do the same thing? I have a rebuilt water pump (old one still on the car). Would I be able to connect the radiator hoses together and loop the heater hose and get the same result or would that do damage to the motor. If this is possible what would be the best way to flush the motor after?

I would not put an acidic compound such as vinegar in my engine. Most block cleaning chemicals are alkaline based. Before the move to greener chemicals radiators were boiled in a solution of caustic soda and water.

You need to be careful about cleaning the system too much, especially if your radiator and heater core is very old. Rust and corrosion are very good pinhole sealers. Once you clean them out, your cores may look like garden sprinklers.

Many moons ago in one of my business ventures, I owned a radiator shop. Many radiators that never leaked a drop became junk once they were cleaned. Caveat emptor.

I would flush with fresh water, drain the system, and then refill with distilled water in a 50/50 solution of a modern antifreeze such as G-09.

[Bob W.]

Re: Rust in motor

The radiator is out of the car as well as the heater core. I was going to loop the heater hoses and loop the upper and lower radiator hoses. My radiator guy didn't think it would hurt anything since I am replacing the water pump anyway and the radiaitor and heater core are not in the car

[Joe L.]

Re: Rust in motor

The radiator is out of the car as well as the heater core. I was going to loop the heater hoses and loop the upper and lower radiator hoses. My radiator guy didn't think it would hurt anything since I am replacing the water pump anyway and the radiaitor and heater core are not in the car

Bob-----


You can loop the heater hoses. In fact, that's what some folks do as a "temporary" solution when they have a heater core leak.

As far as removing the rust from the block, I'd use Prestone Radiator Flush. This is a citric acid-based solution and will not damage your cast iron block or heads.