Overheating Again


Hi all - please let me take this opportunity to say a quick hello to you all as I am new to the Forum...

Well pleased with my Hijet EFI 993, which I bought 3 months ago, although I do have the occasional overheating problem.

My question is as follows:

Should coolant pass to the expansion bottle from the engine manifold filler cap during warm up and before the engine is up to temperature. I have noticed that the cap valve seat is slightly corroded and a previous owner has made a new rubber gasket for the spring loaded part of the cap which I assume is for pressure relief on overheating.
Can anyone also tell me how the system recovers any water that does flow to the tank.

Cheers John.

N.B I have carried out the correct procedures for filling and bleeding the system and again short journeys seem to be ok - when I have ruled out the pressure side, I will move on to Stat and fan. - Water pump seems ok...

John You shouldn't get

You shouldn't get coolant overflow into the header tank until the engine is up to or beyond normal working temperature.
The fluid passed to the expansion tank can't get back into the engine, only out onto the road via the overflow pipe.
You may have a week coolant cap seal that is causing this.
Are you having any trouble with your heater?
Try cleaning the cap seat and fitting a new cap.
If the problem persists it could be a failed termostat or the dreaded Cylinder Head Gasket


Late Reply

Thanks for that reply Littlevanman - sorry for the late reply - yse it is looking like the cap seat on the pipe may be the problem. have yet to find the thermostat to check it's functioning correctly.

On the look out for an electrical schematic at the moment to check out the fan.




The Thermostat is located at the rear of the engine under the blister cover behind the 2 front seats, you need an 8 and 10 mm spanner to remove the cover and a 13mm spanner to remove the 2 screws on the thermostat cover.
A new thermostat can by bought from Halfords


97 HiJet 993cc overheating

Hi - following this hassle and note your reply re thermostat? which brand or type do you buy at Halfords? also, do you or anyone else know what brand, type/size of rad caps for front and inline rads to buy?
my great van ran beautifully for over 5 years with a new rad but now has all sorts of overheating probs which I am trying to overcome.....
Thanks for your information.

Radiator fan

Check the bottom of the radiator there is a temerature switch therre that can go wrong.
Remove the switch cap and short out the pins of the plug.
This will complete the fan circiut and it should run whether the ignition is on or not.
There is a plug in the motor lead close to the motor, so if the motor doesn't run , you could introduce 12V at that point


whats the pipe called or where can i get a new one?

im looking to replace my corroded pipe, that runs along the top with a cap on it.. but when asking i get a puzzled look. does anyone know what the pipe is called or even where i can get a new one?