Hi guys,


I own a 1984 G30 5.7 V8 and about 60k on it. It's an RV.

It sat for a month or two for other tire issues, but when I started her up and took her for a spin a week ago, she began overheating. Belts are fine.

It's been suggested I change the water pump, so I did that, no go. I changed the thermostat, nothing. It seems coolant isn't being sucked up from the overflow. I realize sometimes thermostats are bad out of the box they say, but I'm thinking that's not the issue. Fan is spinning fine. Overflow is plenty full.

It also diesels when I shut it off and the temp is up there.

Thanks for your time.

 

When you filled the rad after changing the water pump you ran it up to temp with the rad cap off right? If not then there is not enough coolant in the block. You need to run the system till the thermostat opens and the upper rad hose warms up. Then you put the rad cap back on......
The overflow is for expansion, but only from a full system.