Bus 366 - Overheating

[jaredg]

So I finally resolved my timing issues with my 366 chevy bus. Now another problem: After a long drive today with the bus, towards the end I noticed the thermostat gauge needle going real high. Once I got the bus back, I noticed a high pitched whistling coming from the engine bay. I got out, noticed steam and the overflow cap popped off (it had always been very loose). I put it back on, started her up again and still a high pitched whistle - from the little whole in the cap. Is that supposed to be a hole? Did a fitting blow out? This is getting really frustrating. So I finally got the timing perfect and the bus has been running better than ever these past few trips. The new holley carb has really helped too, it has more power and there are no signs of engine run-on "dieseling" on shut down. Today I took her for a long trip and as I was coming back I noticed the temp gauge rising. Got the nervous pit in my stomach. Tell me this is not a blown head gasket issue?

[pm26]

First, eliminate the obvious. Remove the thermostat and replace it with a thermostat of proper rating. There could be a wrong temp rating thermostat in there. If that does not help, remove the radiator and have it pressure tested. It may have a small leak somewhere. I would replace that overflow bottle cap too. Finally, I would replace the water pump if nothing else works. The impeller can be broken meaning that the water pump does not work at all.

[tunseeker1]

ok time for my stupid advice again.

 

I would service the cooling system

1. drain the cooling system

2. remove thermostat

3. fill with water and leave hose running on low setting.

4. start engine and let run until it seems like all water coming out clear.

5. drain system again.

6. find out capacity of total cooling system and divide that number by 2

7. add that amount of straight unmixed coolant to system

8. top off with water.

 

next-check timing. bad timing can make an engine run hot.