98' Blazer Constantly overheating. Out of ideas
 

My sister has a 98 Blazer(the small one) and it has a problem with overheating. I am waiting for a list from her but, I do know that the following items have been replaced.

Water pump
thermostat
clutch fan
Fluid Flushed

What else should I check/replace?

Timing and/or timing belt?

Radiator. Does it actually flow?

Head gasket

Could be a blockage in the radiator or the head somewhere.

I read somewhere that a bad catalytic converter could cause an engine to overheat. Has anyone experienced this?

Do you know how I would go about testing this?

If it was the head gasket, would I see oil in the antifreeze?

I'm pretty sure a small combustion chamber to water jacket gasket leak will blow out water without really having "oil" in the AF.

Does it start blowing out water before the idiot light comes on? That would probably be an indicator.

If you can pull a cap and look through the tubes and they are clear, fine but if you can't may have to pull an endcap and/or have somebody flow test it.

Most any muffler shop will test the cat backpressure for free.