Thread: Out of coolant & ideas

Originally Posted by rangieman

Im talking about the fan on the engine so no not a electric fan .

Yep same here.

I hope it is the radiator, after so much expense! Out of interest what brand was the new thermostat that you fitted, as there are some that work better than others? I had a very bad experience myself with a well-known leading brand that nearly cooked my engine on a couple of occasions.

Failing that, I would be tempted to check that there are no combustion by-products (Hydrocarbons also referred to as HC) entering the cooling system. Due to the layout of the D2 cooling system, if there is any volume of gas accumulating in the top hose (the highest point of the system) then it will rapidly stop the flow of coolant to the thermostat bypass. That will cause it to boil very rapidly, as the thermostat will close as soon as the bypass flow stops.

You can check the coolant system with a proprietary block testing kit such as this:

Block Tester™ - Test for a Blown Head Gasket with the Original Combustion Leak Tester by Test ToolsTheir site contains excellent instructions.

Alternatively it is possible to use a four-gas exhaust analyser to do the job. If you put the exhaust probe into the top of the tank and watch the HC reading, it will surge up if there are any combustion products in the tank. Note that it is absolutely critical that you don't allow the probe to draw in any coolant at all, as it will destroy the sensors in the analyser immediately. These sensors are usually very expensive too, and require calibrating.

Good luck!