4200 engine rebuild

[mbis]

Replace the pump. Usually a good time to do the belt thermostat and hoses. Lower hose probably has a spring innit to keep it from collapsing. Pull the thermostat and flush the engine. Make sure there is no blockage.

When you say flush the engine do you mean run water through it

 

[mike48130]

When you say flush the engine do you mean run water through it

I would start with that. If you still have issues after a new waterpump and thermostat you can flush the whole system with radiator flush which is just a mild acid.

Is the thermostat new? I would pull the belt first and check the wp bearing. If good than try the thermostat first. It's cheap.

 

[mbis]

I would start with that. If you still have issues after a new waterpump and thermostat you can flush the whole system with radiator flush which is just a mild acid.

Is the thermostat new? I would pull the belt first and check the wp bearing. If good than try the thermostat first. It's cheap.

Thermostat is new the first thing I tried. Bearing isn't wobbly and spins nice

 

[mike48130]

Pull the pump and see if the impeller is good. I've had pumps be bad that looked good. Did you put the thermostat in the right way. Some will fit both directions but there is a right way.

 

[mbis]

Pull the pump and see if the impeller is good. I've had pumps be bad that looked good. Did you put the thermostat in the right way. Some will fit both directions but there is a right way.

This thermostat can only go one way. Can't see the impeller it is encased

 

[mike48130]

There should be a rear plate that can be removed. I would just replace it with new gaskets and hoses.

 

[mbis]

There should be a rear plate that can be removed. I would just replace it with new gaskets and hoses.

I took that off like you said
Impeller looks good

 

[mike48130]

There's really nothing in the engine to cause overheating Unless your timing is way off. But if it is running good but overheating you need to look at the cooling system. I would replace the pump and see what happens. New hoses too

 

[mbis]

There's really nothing in the engine to cause overheating Unless your timing is way off. But if it is running good but overheating you need to look at the cooling system. I would replace the pump and see what happens. New hoses too

I want to flush this block out first you think?

 

[mike48130]

I would. Not sure what the pump looks like but if there was an opportunity for internal leaks then the pump just cavitayes and doesn't pump. You need to pull the thermostat to flush the block.