I could really use some help with this one. The engine is running hot to the point to where coolant is boiling in the overflow. We have changed the thermostat, a couple of sensors (not sure which ones), and flushed the radiator twice. I have run out of ideas and would appreciate any help I can get. The engine is a 5.0 TPI. Thanks in advance.

 

Is it overheating on the highway or the street?? Is the radiator fan coming on??

 

The fan is on. It'll heat up on both the highway and the street.

 

Two things may be causing this, well Maybe 3.

1st.....and the worse case, is the Heater core may be plugged.. Once the vehicle has warmed up a bit touch both hoses to the core to see if they are equally hot.

2nd.....and not too bad, is the lower rad house may be collapsing, causing the restriction of flow.

3rd.....You have a air lock in the system, try loosening the rad cap half way off, let the car run for a considerable amount of time..so it gets to full running temp. This may help release and air pocket.

Opp make it 4 things..

Your water pump may be going for a crap, but I would check these other reasons first.

 

86 do you notice a loss of power in the engine at all? any hard starting? (when the car is warm)

 

Thanks Cruzin Kaz, I'll give those a try. Quick_Trans_Am, yes there does seem to be a loss of some power.

 

allright well if none of the other stuff works, I would check your timing, it it's too far advanced, it can cause boil over at any speed, and loss of power as well... give that a shot if nothing else works... it should be around 6 degrees BTDC.