I'm having some issues with my '89 Sierra with a 305 that was left to me by my Uncle when he passed away. It has a tendency to overheat at random times. Also, randomly, it acts like it's running on 2-3 cylinders and continues until it is shut off and left to sit for a while. He had taken it to a mechanic a year before he passed but they couldn't find out what was wrong with it. Which has me baffled.

These two problems happen independently of each other. Sometimes the truck will go for days running perfectly and then out of the blue it will overheat or stutter. I will point out that the overheating problem happens more often than the stuttering problem.

I've changed the plugs, wires, cap and rotor, thermostat, and new hoses. When I flushed the engine the water coming out was EXTREMELY orange which leaves me to believe either my Uncle or the mechanic that worked on it ran straight water in it. The oil isn't milky so I think the head gaskets are still good. Also I couldn't see any coolant coming from the weep hole on the water pump.

What can be done about the rust that has built up inside the engine? Any thoughts on the overheating or stuttering?

 

Has it actually overheated (water boiling out) or are you just going by the gauge? A temperature sensor can cause the sputtering your talking about. Do you have a check engine light? If not, does it at least come on when you first start it and then go out (indicating that is does work)?

 

It boiled over once before I knew it overheated. Most of the time when the temperature starts going up, it's at highway speeds >55 MPH.

The service engine light works when you first crank it but it has never came on while driving it.

 

If you have a lot of rust coming out, you may have a clogged radiator. You could take it to a radiator shop to have it checked out and maybe flushed/rebuilt.

 

There would be rust inside the engine block too, right? Can the radiator shop flush the engine to remove the rust?

 

I'm sure they could. You can buy a flush kit yourself at the auto parts store and it may be worth a shot. If your radiator is really plugged, the shop may be the way to go. Good luck.