2017 Superb III (190 DSG) - water temperature - sudden increase then fall

[chalkstorm]

Hello all

 

I have searched the forums and I'm pretty sure I know the most likely answer (a sticking electric water pump) but was thrown off a little by the conversation with the dealer this morning.

 

In September, my car had a service (I've got the All in one insurance which covers that) and a camblet/water pump change (5 yrs old), which I paid for.  All good so far.

 

2 months later, yesterday, heading towards the motorway for my 70 mile commute, 3 degrees outside...  all is well until I join the motorway (takes me around 20 minutes of gentle country lane driving to get there).  Everything as expected, heating working nicely.  I join the motorway and put my foot down to join.... and then over the space of the next 60 seconds I'm in the outside lane (70mph ish).  However, the last acceleration felt subdued and at that point I noticed the temp gauge at almost 130 (not quite in the red) - but no warning lights.  Woooaaah I thought and gently backed off and worked my way back to the inside lane - ready to pull over.  Probably taken my 20 seconds by now and I notice the gauge dropping.  Within another 20 seconds it was back at 90 degrees.  I didn't pull over (dark & wet hard shoulder) but watched it all the way into work and it didn't move again (as has been the case for 5 years).  Got to work, popped the bonnet, water level ok and hot.

 

Later, I needed to head home.  This time I'm watching the gauge very closely and it took maybe 10 mins of town driving to get to 90 degrees.... where it sat until I joined the motorway.  I join at a 50mph section so it was fairly gentle but the gauge rose to maybe 110 degrees where it hovered for 20 seconds before dropping back to 90 again, where it remained all the way home.

 

I called my local Skoda dealer this morning, explained the issue/symptoms and they know the history (they did the service/cambelt/pump).  Receptionist suggested "it may not be covered by your warranty".  Now, maybe that's the stock answer but based on what you lot say in other threads, sounds like a sticking sleeved water pump, which is 2 months old that they replaced.  Wonder how they will diagnose with no warning lights?

Anyway, does this sound like a water pump issue?

 

Thanks!

 

Si

 

Edited 22 November, 2022 by chalkstorm

[Vlady]

Hi I have never noticed anything like that on my Karoq or any other cars I have had but I never paid attention to the temperature gauge as much as you did.

 

I think your thermostat might be on the way and doesn't have an intermediate position, yours could be just fully closed or fully open. It needs to be fully closed when its cold outside and the car warming up using short loop in a heating/cooling system, to provide you with warm air quicker, when the car heats up, thermostat should gradually open until it is fully open to engage a longer loop in a heating/cooling system. It is a simple explanation but I hope you get the meaning.

[chalkstorm]

Not had a sticking thermostat since my 1978 Mini 850!  Hope it is that and not the pump (although that should be covered by the warranty)

[Ootohere]

It sounds like the secondary thermostat. The relevant thing is the DSG. 

Quite common, not an expensive fix, often missed and it should be easy to find the threads and posts on this forum.

Sorry right now i can not link them. 

 

EDIT.

Bumped the Water Pump thread in the Kodiaq section but not a 2nd Thermostat thread. 

Edited 22 November, 2022 by toot

[chalkstorm]

50 minutes ago, toot said:

EDIT.

Bumped the Water Pump thread in the Kodiaq section but not a 2nd Thermostat thread. 

Interesting thread, thank you.  I'd like to work out how to remove the connector when it's working properly to get me through the next week or so of commutes but suspect I'd break something....

[Crasher]

To me that is failure of the electrically controlled main water pump, terribly unreliable. One point, don't obsess about the temp gauge readings, it is programed to read 90 at a real 77 and still read 90 at 117 so if it goes above 90 the actual temp will be 118+. We only fit genuine pumps and belts so when this happens (as it has) it is the appropriate VAG group main dealers problem, not ours. This is the Superb we did last week and the original pump had failed but it was not over heating

 

 

 

[chalkstorm]

1 hour ago, Crasher said:

To me that is failure of the electrically controlled main water pump, terribly unreliable. One point, don't obsess about the temp gauge readings, it is programed to read 90 at a real 77 and still read 90 at 117 so if it goes above 90 the actual temp will be 118+. We only fit genuine pumps and belts so when this happens (as it has) it is the appropriate VAG group main dealers problem, not ours. This is the Superb we did last week and the original pump had failed but it was not over heating

 

 

 

 

Thanks Crasher.  I'm hoping it's something as simple as that (albeit annoyed as the pump is 2 months old).  

[Crasher]

As I said, that's why we use genuine, then someone else has to fix it.

[chalkstorm]

7 minutes ago, Crasher said:

As I said, that's why we use genuine, then someone else has to fix it.

I'm assuming the Skoda dealership used a genuine part!  My worry was that without warning lights, there'd be no code for them to check - and if it's intermittent, they'll claim no fault found (despite it appearing to be a very common issue).

 

[chalkstorm]

70 miles this morning with totally normal behaviour... 🤔

[Crasher]

The two week did last week both had failed water pump but no symptoms.

[Crasher]

Doing another on a T6 tomorrow.

[chalkstorm]

Well well well....  just had a call...  car not ready so "can I keep the courtesy car until tomorrow."  "Yes, sure - what was it?"  "sliding thing on the water pump".  Ahhhhh.

 

Only changed 2 months ago!  Luckily covered under the warranty.

 

I've probably covered 1,000 miles since the symptoms and not seen them again at all!

 

Thanks all!

Edited 1 December, 2022 by chalkstorm

[chalkstorm]

I normally stop the free car wash (one sponge / gritty scratches) but missed it today 😞

 

Edited 2 December, 2022 by chalkstorm