Aircooled VW South Africa

Hi all
I need some help with an overheating problem on my 2002 Opel Zafira 1.8cd. Car starting overheating coming back to cape town from Nelspruit temp gauge climbs the minute the car starts climbing a hill once it hit the 100 degree mark on the gauge I immediately pulled over and let it cool the spanner light and cooling system light came on the dash as well. The problem started after colesberg I pulled over a few times when the car started running hot. I managed to nurse the car back to cape town. The temp gauge still acts weird climbs to the middle mark then drops to the 80degree mark about 2mins and then stays at the middle after starting the car from cold but still wants to climb when going uphill. The car also sounds slightly rough since it ran hot the first time after colesberg still drives ok but also seems sluggish. There is no oil in the water or visa versa and the cooling system is still holding pressure. I am thinking it might be a thermostat problem or gunk in the cooling system, I did replace the thermostat about 1.5 yrs ago with a mahle make one. The car has 241000 km on the clock, also cam belt and water pump were replaced a yr ago or at 227000km
Thanks in advance and sorry about the long post

sounds like thermostat or bad temp sensor.
It might be worth considering having a compression check done - if the exh valves are leaking, it could lead to your sluggish performance and also overheating the valves and seats, in the process adding plenty heat to the cooling water which the system cant get rid of properly.
Or maybe you have so much gunk stuck to the front of the radiator that it isnt cooling as it should?

It might be worth considering having a compression check done - if the exh valves are leaking

Check for water coming out the exhaust - the above causes this.

Although when I checked the compression on the Ford allseemed OK but 3 valves were leaking.

Is your thermostat stuck?

How old is the radiator? Either replace or get it looked at by Radiator King in Maitland/ Salt River

Start with the thermostat. Put it in boiling water to check if it opens.

Me thinks you have air locks in the water system.
Are you driving the car without antifreeze, all cars now days must run on anti-freeze.
If no anti-freeze, the thermostat would rust shut, and only open now and then as you have said is happening.

Herman

Another thing I never mentioned is that the car broke down 150km from Nelspruit on the way back down to cape town had it towed back to Nelspruit turned out a large vacum pipe came loose at the throttle body so I'm wondering if that didn't cause it to run extra lean damaging ex valves.
When I had the towed back my father in law(a master technician at ford) helped me sort the pipe out and also redid the cam sensor wiring(insulation was flaking off) we did perform a compression test but all cylinders had the same reading about 140 psi, at first we thought the car had burnt a valve but the comp test proved otherwise, after the pipe and sensor was sorted it ran fine until we hit the high temperatures in the free state and karoo then the car started running hot.

The car still has the original radiator I think(I am the 3rd owner) and I always run good quality antifreeze which gets changed every year. The thermostat and temp sensor were replaced at the same time 1.5 yrs ago (the thermostat comes as a complete unit including housing and temp sensor)

There is no water coming out the exhaust either but I think Dave might have a good point regarding the radiator I think I need to get it checked out. Also I always run the car with the heater on and coolant bottle cap off after I do the antifreeze change I let it idle for 10mins until nice and warm then replace the cap

This problem only surfaced after the breakdown 150km out of Nelspruit and only when travelling in high outside temperature, I never had a problem driving up to Nelspruit even in hot weather.
I still fear I might have burnt a valve as ecu is putting out a misfire on cyl 4 error code even though you can't feel it but when I get a chance need to check the thermostat first

Thanks guys for all of the suggestions keep them coming pls

I can get a new thermostat for r280 for the complete unit but first need to check a few other things

Also check your thremo switch on the electric fan. If that is faulty it does not switch the fan on which can lead to overheating at high ambiant temperatures or even high power demand situations like going up a steep hill or mountain pass

Also check your thremo switch on the electric fan. If that is faulty it does not switch the fan on which can lead to overheating at high ambient temperatures or even high power demand situations like going up a steep hill or mountain pass