Hi All,

I recently had my cambelt changed, and as recommended the water pump was changed at the same time ( 2012 2.0 diesel 140, DSG, 

mileage is 97,000).  When I got the car back, it no longer maintained constant operating temperature.  It would often struggle to reach 90 degrees and under light loads or going down hills it would drop, sometimes as far as 70degress, even though in the previous 5 years I have never noticed it ever deviate from 90 degrees once warmed up.   It also seemed much slower to warm up.  At the sametime I became aware of a lot more diesel "clatter", especially in the range 1500 to 2000 RPM, in second and third.  I had the emissions scandal upgrade done at the same time, but not sure if this is relevant.

Skoda main dealer suggested changing the thermostat.  They wanted over £300 for this, so I bought the part from them and had it fitted by a local garage.  However, the cool running problem has persisted.  It could be a duff new thermostat, I guess, but could a faulty temperature sensor be to blame?  Also, is the same temperature sensor data used by the ECU to determine fuel delivery and injection timing?  If so, could this also be causing the clatter, as a result of detonation or less well controlled combustion?  Any ideas and thought appreciated?

I am so outraged when I hear garages 'guess' a diagnose at YOUR expense!!

They did a job, messed it up, told you the wrong thing was the problem and cost you more!

Time and time again they do it with NO comeback.

What other industry would we put up with it?

Sounds like it was the "fix" to me.

Keep going back till they sort your car out - they messed it up and have promised at national level that any problems with the "fix" will be put right

But I have to somehow prove that the "fix" is to blame.  They have me over a barrel really.  I love the car, and would have replaced with another next Spring - now I might have to rethink the whole brand and its parent company!

I have 2 of the same issues as you on my DSG 170 TDI which has not had the fix. I had a cambelt kit in May, when I bought it.  The temperature issue has been there since. I have a DSG thermostat purchased to replace yet. The diesel clatter happened after my EGR failed and I had a new EGR and turbo fitted. It happenedin the mornings and evenings. Now it does not happen at 5.30am. Only afternoons 4pm. Perhaps something to do with temperature outside ?

Does not last long and goes away after a few miles. 

Watching this with interest. 

I wonder if they got the timing wrong when they fitted the belt. Was it a Skoda garage or an independent? The 23R6 update is unlikely to be at fault here - I'd expect that to cause quicker warmup than you're used to if anything.

Thanks Chimaera.  The cambelt was done by a "master tech" at Skoda main dealer.  I did wonder if they might have got the timing wrong, but most of the time it runs well.

This evening I climbed and descended the 200m altitude difference from the main road to May house twice to make sure it was fully up to temperature.  I videoed the gauges on the second descent to show to the dealer - last time it was there it behaved ok when I went out with their mechanic!  The clatter was very bad at the bottom of the hill under moderate loads once the engine temp had dropped to 50 degrees.  Might try to upload the video ( though 5 minutes of dash gauges is not the most exciting entertainment!)

Gav-is-gon, how much did they charge you for a new EGR?

9 hours ago, JPL1 said:

Thanks Chimaera.  The cambelt was done by a "master tech" at Skoda main dealer.  I did wonder if they might have got the timing wrong, but most of the time it runs well.

This evening I climbed and descended the 200m altitude difference from the main road to May house twice to make sure it was fully up to temperature.  I videoed the gauges on the second descent to show to the dealer - last time it was there it behaved ok when I went out with their mechanic!  The clatter was very bad at the bottom of the hill under moderate loads once the engine temp had dropped to 50 degrees.  Might try to upload the video ( though 5 minutes of dash gauges is not the most exciting entertainment!)

Gav-is-gon, how much did they charge you for a new EGR?

I had the turbo and EGR done together they are about 2k. However I have been told it's roughly £750 just for the EGR alone. I found one or 2 threads about the DSG thermo stat affecting the dash needle. I ordered it from Autodoc was cheap about £30 I think from Germany. Please do your own research on if it's needed. Some say it's fixed their issue. I just have not plucked up the courage to replace it myself. 

Thanks, Gav-is-con.  I was not aware that the DSG had a thermostat or that it was linked to the dash guard.  I will research this.

i guess I might have to investigate a new EGR, but probably best to check that newt thermostat is not faulty first!

 

It may be totally irrelevant to the issue you're having but many  years ago (early '90's) I had the timing belt on my Montego diesel estate replaced by a main dealer. On collecting the car I immediately noticed a quite distinct change in the engine's performance so I checked the injector pump timing (good old days eh?) and found that I was unable to adjust the pump sufficiently to get it to the correct timing position. I returned the car to the servicing dealer and they eventually admitted that they had fitted the belt one tooth out! Ran fine after it was re-fitted correctly.

 

Moral of the story ..... don't assume that the "Master Technician" got it right!

 

Drefaldwyn (feeling a bit nostalgic).

 

Scary thought, but a distinct possibility.

i went to the dealer today.  They would, out of goodwill, replace a long list of injection/ induction components for 24 months after the emissions fix, including the EGR, injectors etc.  However, they have to be demonstrably broken first, and I have no fault codes yet.  Failed EGR is lookin the most likely problem.  Watch this space!

Sporadic temperature gauge immediately after the cambelt, water pump and coolant have been changed?

 

Coincidence? No, of course not. You need to be firmer with the dealer. Something they have done isn't right.

 

Additional engine noise immediately after the emissions software update?

 

Coincidence? No, definitely not. Why oh why did you have it done? There are threads on every page warning about the dangers and why those risks simply aren't worth it.

 

After paying main dealer prices for a cambelt I'd be dropping it back off with them, taking a courtesy car and asking them to call you when it's fixed.

Silver1011, I think you are right.  That will have to be next week's project!  I will let people know how it goes.

1 hour ago, silver1011 said:

Sporadic temperature gauge immediately after the cambelt, water pump and coolant have been changed?

 

Coincidence? No, of course not. You need to be firmer with the dealer. Something they have done isn't right.

 

Additional engine noise immediately after the emissions software update?

 

Coincidence? No, definitely not. Why oh why did you have it done? There are threads on every page warning about the dangers and why those risks simply aren't worth it.

 

After paying main dealer prices for a cambelt I'd be dropping it back off with them, taking a courtesy car and asking them to call you when it's fixed.

I'd hold off blaming the update for engine noise until the timing belt is properly sorted out. I wouldn't bother arguing anything about the update for now: keep the focus on the fact that they botched the timing belt job and make sure they fix it. Blaming the update gives them too much latitude to wriggle out of fixing it: "Oh we're sorry but it's done now and you'll just have to live with it, we can't undo it, blah blah blah." Keep them focused on one problem that you know they've caused until it's sorted out.

If the cam to crank timing is out, it'll certainly cause poor running and extra noise. On my old Passat (1999 with a VE engine), the timing was off by half a tooth the first time I did the belt on it and when I had it right it was noticably quieter and smoother.

The diesel chatter I take it you are getting it all the time at the rev range mentioned?

The thermostat is there to maintain the engine temperature.

If it is dropping after being up to temperature, I can't see it being anything other than the thermostat stuck open.

 

If the timing belt were out it would make the engine run less efficiently so produce more heat.

 

One check you can do is start the engine from cold.

When the temp guage is around 50 - 60c stop the car somewhere safely & open the bonnet.

Feel the top of the radiator, it should not even be warm.

 

If it is warm then water is circulating when it shouldn't.

The only thing stopping that is the thermostat.

Dear All,  an update on the fluctuating temperature.  My local dealer kept the car for a couple of days and eventually tracked down someone at Skoda UK who had seen this problem once before.  They suggested checking the DSG cooling system thermostat.  Local dealer techs did  not even know there was such a thing!  When they took it off they could blow through it without any resistance.  Fitted a new one this morning (about £25 for the part) and now it runs fine - just as it used to be.  So just the £200 wasted on replacing the main thermostat that was probably fine all along!  Thanks to everyone for your comments, advice and help.

11 hours ago, JPL1 said:

Dear All,  an update on the fluctuating temperature.  My local dealer kept the car for a couple of days and eventually tracked down someone at Skoda UK who had seen this problem once before.  They suggested checking the DSG cooling system thermostat.  Local dealer techs did  not even know there was such a thing!  When they took it off they could blow through it without any resistance.  Fitted a new one this morning (about £25 for the part) and now it runs fine - just as it used to be.  So just the £200 wasted on replacing the main thermostat that was probably fine all along!  Thanks to everyone for your comments, advice and help.

That tells me I need to do mine as recommended by others here too. Feedback helps me too 

How is your diesel chatter when cold or your own circumstances any better?

Shame the dealer never replaced the Thermostat as they would of had to refund you for wrong diagnosis.
Can't believe they never knew about the DSG Therm...I had this problem with mine intermittently and replacing DSG therm solved it completely fot mine from Dingbros for about £25 Looks like this quite easy to fix

Edited 24 October, 20178 yr by DEL80Y

On 24 October 2017 at 09:43, gav_is_con said:

How is your diesel chatter when cold or your own circumstances any better?

Diesel chatter is still there when gauge is between cold and normal running temp - but then it always was.  Car warms up much more quickly now. 

On 24 October 2017 at 13:55, DEL80Y said:

Shame the dealer never replaced the Thermostat as they would of had to refund you for wrong diagnosis.
Can't believe they never knew about the DSG Therm...I had this problem with mine intermittently and replacing DSG therm solved it completely fot mine from Dingbros for about £25 Looks like this quite easy to fix

Yes, I lost out there.  I am disappointed that the main dealer did not have the knowledge or experience to deal with this.  The thermostat job was their first "stab in the dark", but at over £300 I was not willing to let them do it.

On 26/10/2017 at 21:52, JPL1 said:

Diesel chatter is still there when gauge is between cold and normal running temp - but then it always was.  Car warms up much more quickly now. 

Wierd thing now morning temperature has dropped. Does not seem to do it in the morning. Only when I leave work at 4pm. So outside temperature has a bearing when the noise will be present.