Bad Thermostat?

[rboltz]

Drilling a hole was what I thought about last night. I figured a small hole can't hurt the overall operation and will allow the air to escape. I'll try it today and post the results. The fact that the thermostat housing stays relatively cool tells me air is trapped there. We shall see.

[brute4c]

I look for the hole on the thermostats when I buy them...no hole, forget it...I learned on the truck as I referenced above somewhat why a tiny hole is so important.

[randyscycle]

One thing I have found helpful, is to find the highest point in the cooling system and remove either a sender or some component so that I can fill until the water is at that point. That all but eliminates any possibility of trapped air.

Yes, air can and will get trapped in the cooling system and it will not move out by the pump alone. Ford 3.8 V6's and GM 2.8's of the mid 80's were the worst offenders for this. Nearly impossible to bleed the air from and even harder to fill.

There was a tool made later, that applied a vacuum to the cooling system, then allowed you to draw in the coolant through a hose, thus completely filling the system without a chance of air trapped in the water jacket.

Another method we used then, was to go to the highest point on the cooling system, and drill and tap a suitable location there, then add a small petcock to allow you to open it while filling and purge the air. Some European cars came this way from the factory. Saab and Volvo come to mind.

[rboltz]

I think the small hole did the trick. Drove it around the farm fields and it came up to the proper temp and stayed. All hoses got warm. I then let her cool down and topped it off. Won't know for sure until I can get her out on the road, which will be awhile. Another item to add to the 715 quirks list. On to the next project, the vacuum pump!

Thanks guys!

[brute4c]

The thermostat pretty much is the ighest point of the cooling system on the stock 230...so having the hole in the thermostat becomes very critical.

[randyscycle]

The thermostat pretty much is the ighest point of the cooling system on the stock 230...so having the hole in the thermostat becomes very critical.

Makes good sense. Some thermostats have the hole and some have a little check valve in them.

[airborne]

Learn something 'NEW' everyday. NEVER thought about that. I AM smarter today!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!