Over the weekend the engine management light illuminated and the coolant temperature gauge was bouncing all over the place. I've used an ODBC reader to check the problem and it's P2556 - Engine Coolant Sensor. I did stop at a garage to top up the coolant as it was below the minimum line. I drove 1.5 hours home with no coolant loss that I can see, just the temperature needle bouncing like it was at a disco.

 

The vehicle is a 2014 Octavia VRS TSI, mileage is almost 49,000

 

I have the car booked in at a local garage to get looked at tomorrow but I wanted some opinions, is it likely that the problem is just the coolant sensor, or is there a possibility that the water pump will need replacing too? I'm asking because we go away on Friday and will be using the car, I'm concerned the garage will replace the coolant sensor and we break down whilst away.

Edited 27 August, 20196 yr by TheBinarySheep

Difficult to say without doing some test with the system but I would give the software the benefit of the doubt & say its a sensor or electrical connection problem.

Coolant pump problems would mostly give permanant overheating (but e.g. if it is working intermitttantly could also create the same effect that you have seen).

 

When you get it back from the garage, try to get as many miles with it before you go away, just for peace of mind.

...and keep the TotalMobile number closeby just incase.

The sensor has been replaced and all seems well so far.

 

However, over the weekend, before the overheating problem there was a noise from behind the passenger footwell that sounded like someone had shook a bottle of coke and opened the lid slightly, like air and water escaping. I heard the same noise on the way back from the garage.

Another update. long drive tonight, after 30 minutes the temperate gauge started to bounce around again and finally settings at about 1/3rd of the way around. I checked the oil temp, it was 78c. No coolant loss.

 

I suspect this may have something to do with the valves that control the cooling? It seems after a while it's not cooling enough, and then it cools the engine too much.

Further update, garage have tested the car with a computer plugged. Temperate gauge is reading differently to that reported by the computer. Computer is reporting the temps are fine, the gauge is saying something different.

Sorry for all of the updates. I've had to resort to booking to car into a specialist next week. The garage who looks at the car this morning suspected a faulty temperate gauge, but when I told them that when the water gauge was reading around 70-80c, so was the oil temperature via the matrix display, which suggests to me that it is not a faulty gauge but rather the car is having a problem regulating its own temperate, at that point they suggested booking in with a Dealership or a Specialist. 

 

I've ended up hiring another car for the weekend as I don't want to risk driving this one until the problem is resolved.

 

If anyone has had any similar problems, or has any suggestions as to the cause, let me know.

Problem is water pump, thermo stats. bill... £750

Does anyone know if the TSI & TDI use similar water pumps because on the TDI Skoda/VS are offereing a 50% contribution to repairs which would drop the bill to around 350GBP?

It took a couple of days but it's been fixed. For anyone interested, breakdown of the work below;

 

VALVE (4H0121671D) £111.61

THERMOSTAT (06L121111M) £216.79

UNION (06L121131) £6.86

WATER PUMP (06L121012A) £69.76

BELT (06K121605C) £14.48

LABOUR £174.99
TOTAL PARTS £419.50

VAT £121.87

TOTAL £731.22

 

VCDS showed the following;

 

15446 - Blocking Valve for Coolant (N82)

15472 - Engine Coolant Level Sensor/Switch

15462 - Control Circuit for Coolant Bypass Valve

15470 - Insufficient Engine Cooling / Coolant Flow

 

On 06/09/2019 at 13:56, TheBinarySheep said:

It took a couple of days but it's been fixed. For anyone interested, breakdown of the work below;

 

VALVE (4H0121671D) £111.61

THERMOSTAT (06L121111M) £216.79

UNION (06L121131) £6.86

WATER PUMP (06L121012A) £69.76

BELT (06K121605C) £14.48

LABOUR £174.99
TOTAL PARTS £419.50

VAT £121.87

TOTAL £731.22

 

VCDS showed the following;

 

15446 - Blocking Valve for Coolant (N82)

15472 - Engine Coolant Level Sensor/Switch

15462 - Control Circuit for Coolant Bypass Valve

15470 - Insufficient Engine Cooling / Coolant Flow

 

 

Hi there,

 

I was just wondering if the above work carried out sorted your coolant/temp gauge dancing problems?, Was this work completed at a Skoda dealer

 

I am experiencing very similar problems to what you listed above.

 

Thanks.

On 27/08/2019 at 14:20, TheBinarySheep said:

I'm concerned the garage will replace the coolant sensor and we break down whilst away.

For a 2014 car, the symptoms you have just mentioned - are definately part of the a failing water pump.  They either go leaky through the seals or they begin to fall apart internally.  I am surprised about the sensor; they aren't expensive to replace so I would get it done at the same time as the water pump.....sorry....its a non-FL weakness....but the good news is that the replacement VAG part is not prone to failure in the same way, so you should get another five years of motoring without any further issues.

I'm having this same issue with a 2016 VRS 

 

Over the last few months I've had a new coolant header tank, radiator and engine coolant temp sensor switches and a new thermostat and water pump.  The Thermostat was definitely at fault in some way as it threw a fault EML during a trip (fortunately warranty covered that part although I had to pay for the water pump).

 

The problem persists.

 

An OBD11 scan shows fault code P255600, Intermittent Engine Coolant Temp sensor switch....the car goes back to the garage Tomorrow so I'm hoping that sensor IS faulty or that there is a wiring/connection issue that is easy to fix.   Live data on a drove earlier didn't show a coolant spike but the temp gauge did sweep upwards twice during the drive.

@Bobbster  Why did the car require all these parts that have been replaced, were they all faulty? 

 

Maybe a different garage / mechanic is what you really need.

59 minutes ago, Ootohere said:

@Bobbster  Why did the car require all these parts that have been replaced, were they all faulty? 

 

Maybe a different garage / mechanic is what you really need.

The car wasn't throwing any fault  codes initially.  Just the temp gauge sweeping up and down.

 

The coolant header tank was the first port of call as the circuit can fail.

 

One temp sender did later show a fault a couple of weeks later .  Both were replaced because the additional cost was £8.

 

The thermostat tripped the EML and was definitely failing.

 

The mechanic is a good guy, been in business for 30 years, used him for several years without trouble.  

 

But if it's not rectified this time it'll be Plan B, local auto electrician.

 

 

He certainly gets a bit of an income from you. 

Was the radiator leaking?

11 hours ago, Ootohere said:

He certainly gets a bit of an income from you. 

Was the radiator leaking?

He does to a point, but the thermostat was under warranty and the other jobs were all about £80 so not breaking the bank or making me think he's out to rip me off.  

 

No leak from the rad