kzn130 3.0td overheating

[GINGER JOHN]

Hi all i have an L-reg 94 3.0 td. It has been bullit proof reliable. I am now having to sell it as i have a baby on the way soon and i think it knows i want to sell it as this weekend it started to overheat. The temp guage normally sits dead center all day long but this weekend it was starting to creep up. I turned on the inside heater full and this brought the tempereature back down to normal and made it home. When i let it cool down i checked the water level and it was low so topped it up and ran it for about 1/2 hr and it was fine. Just quickly checked the water level this morning before i set off and it looks low again. But i can see any leaks from the hoses and there is no Mayonaise under the oil filler cap. I have heard Cylinder heads can be a problem on the 2.4 but not so much the 3.0. Does anyone have any ideas could it be the thermostat or the fan. and is there any checks or tests i can do to see if it is the cylinder head (i hope its not!!)
Any pointers would be greatly appreciated

[Tallyman]

It could be any number of things. Did you check the water level in the expansion bottle or under the rad cap? Do you run with the front & rear heaters turned on? Were you doing anything different than usual?

If you're leaking water into the cylinders then the exhaust should turn white as you'll be blowing steam out the back. If you just have an airlock in the system then bleeding all the air out should sort it. Have you checked the hoses for any leaks? Is the rad cap in good condition? When was the last time you changed the thermostat? Have you been offroading in it recently? If so, is the radiator blocked with mud? Does the viscous fan spin up properly when the temperature starts to rise above normal?

Any one, or a combination, of these could be the cause. The first and probably cheapest things to try are renew the rad cap and thermostat, then make sure all the air is fully removed from the cooling system. If that doesn't cure it, run a search for overheating on here as there have been plenty of threads, not all to do with cracked heads.

[GINGER JOHN]

cheers Tallyman
Gonna leave work early now and check all them things.