MK1 Cabriolet - Cooling problems

[beausuf]

Hey guys,


Posting on behalf of my brother, in short coolant is not flowing and fans are not kicking in therefore it's getting too hot...

- New thermostat, housing and seals
- Flushed radiator/system at time of thermostat change
- Replaced hose to/from overflow as it was a bit tattered
- All other hoses are in good condition, don't seem to be clogged/blocked/split
- Fans arent turning on at all but are getting power
- Waterpump was replaced approx 10,000 km's ago

In regards to potential cracked head or head gasket, car doesn't blow any smoke or water out exhaust and the oil is not milky so I wouldn't think so? Other things I can think of would be the coolant sensor on the water housing, I'm assuming if this is broken and not sending correct information it won't be telling the rest of the system to flow and to turn the fans on? There's also a bit of coolant leak around this area which makes me more suspicious of it.

Also, a mobile mechanic was out doing a timing belt on another car so my brother asked him to have a quick look, he said he wasn't too sure as he doesn't usually do euro, especially older models but his voltmeter had a temp setting, popped it in the overflow and it reached boiling point in approximately 4 minutes of the car idling if that helps at all.

Any help is appreciated as the car will be sitting until it's fixed would rather not looking at a euro specialist mechanic if possible as they charge at a premium.


Thanks guys

[GeorgeMK1]

Have you tried putting a direct 12v power source to the fan to see if its working?

[sports racer]

Run the engine for a couple of minutes to warm it up and get the thermostat open. Turn it off. Disconnect the top radiator hose where it goes into the radiator and start the engine for about 30 seconds. Does water flow out and keep coming out? If yes then the waterpump is working ok and you don't have any blockages. Problem is the fans.

Can you turn the fans by hand - blades aren't getting caught on anything?

Do what George suggested above, do the fans now work?

Cheers

Paul

[sports racer]

Thought of an easier way to tell if the waterpump is working. Start the engine and feel if the radiator gets warm. If it does the pump is ok.

[MarcusAurelius]

I had thermostat issues with my 8v. My brand new Tridon thermostat wouldn't open and it seems like it would foul on the housing somewhere. It wasn't a faulty thermostat either because it would open if I bench tested it so I'm still running the OEM 70's thermo

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