My car is TDI(190hp) 4x4.

The coolant temperature suddenly runs higher than 110~130°C. It would go back to normal temperature(around 90°C) when I drive slower or stop the car.

The problem doesn't happen every time whenever I drive this car. There is no error code with this issue. What could be the problem?

Obvious questions, first: what’s your coolant level like, and is your fan coming on?

2 minutes ago, DaveMiller said:

Obvious questions, first: what’s your coolant level like, and is your fan coming on?

My coolant level is almost full. My car just finished 45,000 km maintenance service few days ago.

How to check if my fan is coming on?

How old is it?

33 minutes ago, SuperbTWM said:

How old is it?

It's Kodiaq 2018.

is it not still in warranty?

2 hours ago, Richie2019 said:

How to check if my fan is coming on?

Have a look.

When it’s reading hot, is the fan spinning?  (If the fan is NOT spinning, it suggests a fault with the fan/switch; if it IS spinning, it suggests a fault elsewhere, such as blockage, airlock or faulty temperature sensor.)

 

Either way, it gives a bit extra for you to report, when you check it in for investigation.

40 minutes ago, SuperbTWM said:

is it not still in warranty?

Yes, but it hard to figure out which component causing this issue.

I get where you are coming from but anything that could be suggested is purely guesswork without the car in front of them. The water pumps have an adjustable sleeve that can stick, there are also different cooling loops as mentioned above, it could be the thermostat, or it could just be a dodgy sensor reading. I doubt it would be the radiator fan unless you live in a very hot climate as in the UK you hardly ever hear them running on a diesel unless its doing a DPF regen or the air con is on. (which btw is how you could prove they work)

 

You are obviously not going to start tearing the car apart to figure out the issue on the advice of anybody on this forum and risk voiding the warranty so the quickest way to resolve your issue is book it into the dealer IMO.

28 minutes ago, DaveMiller said:

Have a look.

When it’s reading hot, is the fan spinning?  (If the fan is NOT spinning, it suggests a fault with the fan/switch; if it IS spinning, it suggests a fault elsewhere, such as blockage, airlock or faulty temperature sensor.)

 

Either way, it gives a bit extra for you to report, when you check it in for investigation.

Thank you for your suggestion. I will check it when the problem happens next time. But it might be hard to check since the problem only happens while my car is driving.

1 hour ago, SuperbTWM said:

I doubt it would be the radiator fan

 

Could be the fan fuse. Happened to me once.

10 minutes ago, linni said:

 

Could be the fan fuse. Happened to me once.

How did you fix it? The problem happened randomly.

By changing the fuse.

Check your owner manual, tere are all fuses listed.

14 hours ago, linni said:

By changing the fuse.

Check your owner manual, tere are all fuses listed.

Thank you for your information. Do you mean this fuse?

May be your water pump. The symptoms are possibly indicative the pump is intermittently not opening when the engine is warm to circulate coolant. I had this issue with these symptoms on my 190tdi. Water pump replacement fixed the issue. No errors get thrown up when this happens, just a engine that overheats intermittently when temp is reached. Your dealer should be able to confirm if it is the pump.

 

As stated by SuperbTWM above.

Edited 4 March, 20215 yr by jasoncmiles

50 minutes ago, jasoncmiles said:

May be your water pump. The symptoms are possibly indicative the pump is intermittently not opening when the engine is warm to circulate coolant. I had this issue with these symptoms on my 190tdi. Water pump replacement fixed the issue. No errors get thrown up when this happens, just a engine that overheats intermittently when temp is reached. Your dealer should be able to confirm if it is the pump.

 

As stated by SuperbTWM above.

 

Is this the water pump you mentioned?

not sure of PN but its of that design, its the sleeve that sticks IIRC

If the car is out of warranty & you don't want to shell out the £500+ to change the pump, just disconnect the brown electrical connector shown in the picture above.

 

The pump then reverts to pumping all the time, just as previous coolant pumps without the sleeve have always done.

 

The engine might take an extra minute or two to reach operating temperature, but no big deal.

 

 

  

10 hours ago, PipH said:

If the car is out of warranty & you don't want to shell out the £500+ to change the pump, just disconnect the brown electrical connector shown in the picture above.

 

The pump then reverts to pumping all the time, just as previous coolant pumps without the sleeve have always done.

 

The engine might take an extra minute or two to reach operating temperature, but no big deal.

 

 

Thank you for your suggestion.  Will there be a error code generated after disconnecting the brown electrical connector? What would be the side effect?

Edited 5 March, 20215 yr by Richie2019

On 04/03/2021 at 04:47, Richie2019 said:

Thank you for your information. Do you mean this fuse?

My fuse problem was not related to Kodiaq, but I presume yes.

Sometimes it might not be the fuse itself, but a temperature sensor. And lots of other possible causes, like this water pump thing.

 

About radiator vent - when the temperature exceeds 90 degrees, open the bonnet and check, if the fan is working. If not, the problem lies there.

12 hours ago, Richie2019 said:

  

Thank you for your suggestion.  Will there be a error code generated after disconnecting the brown electrical connector? What would be the side effect?

I would imagine that a fault code will be generated, but I'm fairly sure it doesn't bring up the engine/ emissions light on the dash.

You could always add a resistor across the removed plug which would simulate the disconnected solenoid to eliminate the fault code.

 

As stated above, the side effect is that the engine will take a minute or two extra to reach operating temperature.

the more fuel you burn, the hotter engine gets ? mine gets to 115 C when i climb hills at speed drinking at 12 L / 100km

Thank you for all your suggestion. I finally found the root cause of this problem. It was caused by the fan blade of water pump got stuck. After replacing a new water pump, the issue got solved.

On 16/03/2021 at 01:55, chrisluciofg said:

the more fuel you burn, the hotter engine gets ? mine gets to 115 C when i climb hills at speed drinking at 12 L / 100km

Yes, the more fuel you burn, the hotter engine gets. However, water pump will help cool down the coolant temperature to 90°C  in the situation. So this is not normal with your car. 

The problem would happen when the RPM of engine runs higher than 2000 and the engine keeps the high speed for few minutes. After replacing a new water pump, the issue got solved.

The coolant red warning light and buzzer went mental 2 days ago. The temp went shooting up. I stopped and checked for leaks etc. Coolant correct level and had dealer 40k service a few weeks ago and the car is a June 2018 model.

The temp dropped back down to 90 degrees and I aborted my journey and the temp gauge was variable on the way home.

Called Lookers Newcastle-upon-Tyne and knowledgeable salesman advised me NOT to drive it and call Skoda assist who recovered the vehicle and arranged an automatic courtesy car.

Collected my Superb today & it was a faulty secondary coolant pump which is apparently a common fault on these 2 litre VW diesels.

Fortunately everything was warranty but if it had occurred in 3 months time it would have cost ITRO £300-£400 which made me glad its a lease car.

However my replacement is T6 4motion same engine...out of the fat into the proverbial!