Took my car in for a service ~Oct 2025, before its’ MOT was due mid Dec. A few weeks after the service I say a fault (temperature/coolant) come up instructing to turn the engine off and check the coolant. Did that and the coolant reservoir/bottle was full. Mentioned this to the mechanic when I took it in for the MOT and ask him to have a look at it.  MOT passed, the mechanic handed me the key, so I asked about the fault and what the diagnostic came back as - he said “all clear”.

Since then, the fault has come up quite a bit but the frequency has increased from 1-2 times over a journey to almost every 20mins. Called the mechanic and he says to bring it in this Friday, as it could be it needs a replacement coolant bottle. Another (different mechanic at my tyre shop) said previously it may be a faulty sensor. I also noticed the radiator fan stays on for an extended period after the engine has been turned off. I think it being winter has saved my bacon.

Typing this in the car and recorded the dash - from turning the engine on and the fault came on at 08m06s. I’ve even bought one of those Veepeak ODB2 BT scanner to at least have a better understanding but don’t quite understand it.

I’ve lost faith in my mechanic tbh and was wondering if anyone has seen this before, so I’m not going in blind, come Friday.

Long read, but wanted to ensure I gave a good picture. I’ll try and upload a phot/vid as well

 

be grateful with any pointers and thanks in advance

Raff

2 minutes ago, Frique said:

Took my car in for a service ~Oct 2025, before its’ MOT was due mid Dec. A few weeks after the service I say a fault (temperature/coolant) come up instructing to turn the engine off and check the coolant. Did that and the coolant reservoir/bottle was full. Mentioned this to the mechanic when I took it in for the MOT and ask him to have a look at it.  MOT passed, the mechanic handed me the key, so I asked about the fault and what the diagnostic came back as - he said “all clear”.

Since then, the fault has come up quite a bit but the frequency has increased from 1-2 times over a journey to almost every 20mins. Called the mechanic and he says to bring it in this Friday, as it could be it needs a replacement coolant bottle. Another (different mechanic at my tyre shop) said previously it may be a faulty sensor. I also noticed the radiator fan stays on for an extended period after the engine has been turned off. I think it being winter has saved my bacon.

Typing this in the car and recorded the dash - from turning the engine on and the fault came on at 08m06s. I’ve even bought one of those Veepeak ODB2 BT scanner to at least have a better understanding but don’t quite understand it.

I’ve lost faith in my mechanic tbh and was wondering if anyone has seen this before, so I’m not going in blind, come Friday.

Long read, but wanted to ensure I gave a good picture. I’ll try and upload a phot/vid as well

 

be grateful with any pointers and thanks in advance

Raff

I've aded a screenshot, just in case the vid is unplayable

 

 

Level sensor, or quite possibly a poor connection onto it, on the reservoir.

Worth getting some contact cleaner and removing the plug, spray and refit. 
Regards,

Gareth. 

Any progress Fri? 

Please come back to the forum with an update. This update could be of help to other members in the future. 

Thanks, Gareth.