Roomster mk1 overheating issue

[dadof2]

Hi

 

Will take the car to garage, but wondered if anyone had any thoughts before, so I know what to discuss with them.

 

When sat in a traffic queue, if you end up being there for 5-10 mins (slowly creeping forwards), the coolant overheating light comes on.  The coolant level is ok, although it had been topped up with just water when the level was going down a bit so its not pure coolant.

 

Aside from draining and replacing the coolant, what else should I look into? Fans? Sensors?

 

Thanks

Chris

[xman]

Does the radiator fan come on, at full speed? If not it maybe a fan motor, sensor/thermal switch or wiring issue.

 

It could be a failing water pump. Some have impellers that come detatched lowering the ability to pump.

 

Is the coolant a nice and clean colour, if it is brown and murky you may have radiator blockages.

[J.R.]

Engine type please!

[dadof2]

On 29/08/2023 at 10:47, J.R. said:

Engine type please!

 

Petrol

[dadof2]

On 29/08/2023 at 09:23, xman said:

Does the radiator fan come on, at full speed? If not it maybe a fan motor, sensor/thermal switch or wiring issue.

 

 

Silly question but how would I know this? Should the radiator fan only come on when the car is driving or in idle? Only when the radiator is hot? Thanks

 

 

[xman]

On 06/09/2023 at 21:32, dadof2 said:

 

Silly question but how would I know this? Should the radiator fan only come on when the car is driving or in idle? Only when the radiator is hot? Thanks

 

 

The radiator fan cuts in whenver the coolant is too hot.

 

So when you see the red temperature warning light on, pop the bonnet and look at the radiator fan. It makes quite a racket/roar when its on so should be easy to check. DON'T be tempted to touch the fan, you could lose a finger!

 

If it's not spinning like mad, then you need to check the fuse, fan motor, connections, wiring and the thermo switch which afaik is mounted on one of the side cheeks of the radiator. @Breezy_Pete would probably be able to help locate it

[Breezy_Pete]

Radiator fan(s) should also spin up whenever the air conditioning is switched on, which is an easy check in this sort of weather, if the car has A/C and it actually works.

 

When cold air is demanded/supplied, within a short time (depending on ambient temp) the radiator fan or fans should come on continuously at low speed (not that furious/loud). If it/they come on intermittently at high speed (furious/loud), it's generally a good hint that low speed function has failed inside the fan.

 

To test via the thermoswitch wiring, link connections on the loom plug as shown (assuming an A/C equipped car). Thermoswitch usually found 100mm or so above bottom hose connection to radiator.  Quite common for wire breakages adjacent to this loom connector, so worth getting eyeballs on it even if you don't do link tests.

 

 

 

 

 

 

Edited 8 September, 2023 by Breezy_Pete

[mrjgd]

Just had same issue. Radiator hose rubbed on the undertray on mine created a small hole. Can't find the right hose