Yet Another Fabia Temperature Gauge Problem!

[Furby164]

Hi All,

Hope somebody here may be able to help with a rather curious temp. gauge problem.

Car is an X reg. (2000) Fabia MPI Classic with the 8 valve OHV engine. Since I bought it used from a local Citroen dealer about 6 weeks ago, the temp. gauge has always risen to normal working temperature ( i.e: needle vertical at the halfway mark) within the first 2 to 3 miles of driving from a cold start and then stayed there, unmoving, regardless of road speed or conditions. From searching all the previous threads regarding, Fabia temp. gauges, I believe this is normal behaviour.

Last week, on the way to work, I noticed that gauge was barely moving off the stop and, after a 5 mile drive to work was still only a needle width or two off the stop and only really began to rise after I sat in the car park with engine running.

On leaving work, I sat with the engine running to bring temp. up to the halfway mark, but by the time I got home, it had fallen to the quarter mark again. This, combined with the other posts on the subject of Fabia temps. led me to suspect a faulty thermostat.

Yesterday, the dealer took the car in for investigation and replaced the thermostat under warranty. When I picked the car up, they had obviously warmed it up, as gauge was sitting on the halfway mark as soon as I started it up. After approx. 10 miles drive home, gauge had again fallen to the quarter mark.

Today, I started the car from cold and, after a 5 mile drive, gauge had still only risen to just under the quarter mark. I left the car parked for about 5 minutes, while I went to the auto shop for a haynes manual, then restarted the car and gauge immediately rose to the normal halfway mark. It stayed there for maybe 2 to 3 miles, but again by the the time I got home it had fallen to between the qurter and half marks.

What could be causing this? Could it be that car needs new thermostat housing instead of just new thermostat? Or could it be the temp. sensor? Wrong thermostat? Airlock?

Any help or advice would be very much appreciated!

Thanks In Advance,

Regards,

Furby

[fordfan]

The thermostat is integral with the plastic housing and they do break up. A new housing is around £40 + VAT, part number 047121111S. It comes complete with the temperature sensor which on its own is a shade over £22 + VAT.

To confirm if it is broken you can remove the sensor and should be able to see or feel the thermostat.

[Dmac1969]

Yeah its a new housing you should have £31.42 plus VAT, part no as above. Ive just had one on mine due to exactly the same symptoms that you describe. Fitted inc labour and VAT my bill was a tad under £90 , and the car is now back to its former , quickly warming up , self.

[Furby164]

Thanks guys,

Thermostat housing would appear to be the most likely culprit then.

I'm a little reluctant to start messing with anything myself to confirm this however, in case it invalidates the warranty. Given that the dealer isn't a Skoda specialist, I'm wondering how likely it is that they have changed the thermostat on Friday, but not noticed if the clips in the housing are broken? If the clips in the housing are indeed broken, would the thermostat still seat well enough to make them think all was well?

[Furby164]

Just a quick update.

I phoned the dealers to check exactly what work they carried out on Friday and was told that they changed the thermostat, but not the housing. I enquired if they had seen any signs of broken clips etc. inside the housing, but was told the housing appeared okay to them.

The temperature gauge is still barely reaching the quarter mark after a 5 mile drive and only starts to rise towards the half mark after sitting stationary with engine running for a while. It will be another 10 days before they can take the car in to have another look at it, so I'm wondering if driving it like this is likely to do any harm, other than maybe using more petrol than normal?

[Fabia1.4]

I think you should be ok but you will just see your mpg drop to about 25

[ap0gee1978]

I would definitely try and push the dealer to get the whole lot done. If you don't have any luck, I did a technical guide for just replacing the sensor, which isn't 100% relevant, but shows you the housing because it's what the sensor sits in. In order to expand the job to cover the complete housing, you can either drain the coolant system or clamp the hoses either side of the thermostat. It never hurts to change the coolant regularly, so a complate drain-and-refill is arguably the best anyway - but obviously adds extra cost and extra faff ensuring the system's bled properly afterwards. Anyway, to cut a long story short, whichever approach you use, it's a pretty easy swap-out job so if your garage argues the toss, you should be able to put it right fairly easily yourself!

[Furby164]

Hi all, Here's the latest update in the hope that someone can help:

My Fabia went back in to the dealers a fortnight ago, as, after being told that the thermostat had been changed, the temp. gauge was still slow to rise, taking 5 miles or more to reach the half mark and still reading erratically. This time, I was met by the service manager who told me that on the previous occasion they had changed the entire thermostat housing, not just the thermostat. The dealer ran a series of tests, checked the fan, etc. and could find nothing wrong. When driving the car home, the gauge rose to the half mark fairly quickly, with the engine still being warm, but whilst driving along the dual carriageway, I noticed the gauge drop towards the quarter mark, before rising back to the half mark again. As I was slowing to park outside my house, the engine revs just died and the car stalled, but restarted OK.

Since then, the car stalls frequently when slowing for roundabouts, etc. and during slow speed manoeuvres such as reversing into a parking space. Sometimes, the car may not actually stall, but will be on the point of stalling and you can see the revs dropping way below idle and jumping about between roughly 500rpm - 1000rpm.

Because of this stalling problem, the car went back to the dealer again today. On the way to the dealer, temp. gauge hit the half mark within 3 miles and stayed steady for the remainder of the approximately ten mile journey. This was about the first time since my problems began that the gauge has displayed what I would consider usual behaviour. As the dealer is not a Skoda specialist, they phoned Skoda for advice and were able to discover a fault in the upstream lambda sensor. Since the part has to be ordered up, they phoned me to come and collect the car and will phone when part arrives. On the way home, the car warmed up fairly quickly and the temp. gauge rose to half way mark within 2-3 miles. However, by the time I had gone 5 miles down the dual carriageway, the temp. gauge had dropped to the quarter mark and continued to drop until by the end of the journey, it was halfway between zero and a quarter!

I was really pleased with my Fabia at first, as I find it a very pleasant little car to drive, but am starting to get frustrated now, so I'd be most grateful if anyone could shed some light on what may be wrong? Would a VAG-COM diagnosis perhaps provide some answers?

[Tech1e]

Yes we need a VAG COM code list to go on really.

Sounds like it could be a faulty coolant temp sensor, this should have been changed with the housing though assuming gen parts have been used.

It will pay to get someone who knows what they are talking about to have a look at it.

[fab51]

hi furby -

i agree with ap0gee - take the housing apart and have a look inside and see if any of the lugs have broken off that hold the thermostat in place - maybe some mates could help you who like playing with cars - its not a hard job - garages tend to pull the wool over peoples eyes if you are not that clued up - should get change out of £40 for a new one - if you are going to change the antifreeze use the pink long life , not the old cheap green stuff -

hope it works out -

[lello7]

Did this ever get resolved, and what was the main cause:-) experiencing same thing directly after headgasket change (and valves)

[Stewartasb]

tech1e is correct as I had exactly same issues as you so I changed the thermostat and housing and also the temp sensor this resolved the issue im pretty sure its your temp sensor if the thermostat has been changed and possibly they may have air locked your system when changing the thermostat as air in the system will cause the issues your describing.

[sakta]

On 02/02/2021 at 05:18, lello7 said:

Did this ever get resolved, and what was the main cause:-) experiencing same thing directly after headgasket change (and valves)

Its best to make your own thread. This is for the mk1 Fabia, but the fix should be the same. Unstable temperature, always change the thermostat