Radiator cap

Hi chaps I've just bought a 2002 jimny in pink/red for £600 with over heating problems. The gauge never gets into the red but the radiator keeps emptying itself into the overflow bottle. I've already changed the thermostat but now suspect radiator cap but I've had three caps from three different suppliers none of which I can get to fit on to the radiator. Has anybody else had problems getting a none genuine radiator cap to fit.

I have a couple of rad caps you are welcome to for the cost of postage. Maybe try a sniff test to ensure no gases are getting into the coolant if the head gasket is leaking?
Welcome to Bigjimny.

My rad cap looks the same as the one on my Honda 400, you might get one from a motorcycle spares shop if you take yours in to match the pressure.
Check yours has all 3 rubber seals intact.






Seal 1 is the main seal, if this is missing I'd expect some leakage at the rad cap, and the water won't go back from the expansion tank as air will just get in.
Seal 2 lifts up when the system heats up and the water expands so the pressure rises, it regulates the pressure to raise the boiling point.
Seal 3 is the return valve, when the engine cools the water contracts, atmospheric pressure then pushes the previously expanded coolant back in through this valve. The valve part is slightly loose on mine, but it pressurises when hot so it must seal when it is fitted.

Supergaz I've already sniff tested it so I know it's not the head gasket

Facade thanks for the picture the whole of section three is missing from my cap and the caps I got from the motor factors were completely different so I'll order a cap from the dealers.

I got the car cheap as the Suzuki dealer had told the owner the head gasket had gone, they probably took one look at the faded paint work and the odd dent here and there and didn't even bother to check it over properly

Mine is a twin cam, I doubt if it affects the radiator cap though.

If the valve part is missing, you shouldn't be able to pressurise the system. With a cold engine and that valve missing you should be able to squash the top hose and see the water go into the expansion tank, and then come back when you release the hose.

before you order one from the dealers try cam-suzuki he specialises in breaking jimnys