Low coolant warning

[THR32]

Afternoon all,

After three years (18k miles) of faultless running, last Sunday I got the 'STOP - low coolant' warning when starting the car from cold. After stopping and restarting the engine, the warning went away and didn't come back until today, when the same thing happened.

The car is always parked on a sloping road, so it's quite difficult to gauge exactly how much is in the reservoir, but when it's properly warmed-up it just about gets up to the 'min' line in the expansion vessel, and when cold, most of it disappears.

I plan to take it to the stealer to get some coolant to top it up tomorrow, but before I do, does anyone have experience of the 3.2l engine "losing" some of its coolant? Might a blockage that only clears when the engine is up to temperature and pressure be the cause?

Many thanks for any bright ideas!

TH

[Cuprabob]

Had this a few years ago with my R32 but the coolant was just below the minimum level. Got the dealer to top it up and carry out a pressure test and has been OK ever since.

Certainly on older models the coolant level sensor was tempremental and a lot were replaced but I'm not aware of similar issues with the MKV.

Just make sure the dealer does a pressure test+++

[TheEdge]

that shouldnt really be a problem looking at my log i keep for the car I had low coolant on my mark 4 in November 2007 about 200ml then a year later the same amount about half the amount of a can of coke !! the change of temperature has an effect etc ! I only do about 6000 milels a year Id be honestly surprised if your dealer finds any problems with it !!!!

[geo_nr1]

There was a bit of an issue on the MkiV's with this. It was a sensor that used to have a sort of wax in it and it goes after a period of time, basically nothing to do with the coolant level.

[bigface]

i had this problem last year on the mk5. It was due a service within a few thousand miles so the vw guys took it and serviced it, they checked it over saying there is some fault with that engine type but couldnt find it on mine. They were to recall the car again to strip it and look at it again but i never heard from them or had the problem since. At that stage the car had 34k miles now at 41k miles without anymore problems.

[hotdog]

Had the same thing. Coolant level was a bit low, so I topped it up, never had any problems since. Seemed to happen after a really big fluctuation in temeperature overnight. :confused:

[geo_nr1]

Had the same thing. Coolant level was a bit low, so I topped it up, never had any problems since. Seemed to happen after a really big fluctuation in temeperature overnight. :confused:

Thats exactly what happend with the Mkiv's. It was mostly in the really cold mornings during the winter.

Basically the wax didnt solidify in the sensor and the engine thought it was low even though the level was between max and min. As usual, the sensor was only a few quid, it was the labour to change it that was the dearest part but this could be changed in half an hour anyway.

[mb]

Had this a few years ago with my R32 but the coolant was just below the minimum level. Got the dealer to top it up and carry out a pressure test and has been OK ever since.

Same here, happened one Xmas Day (top marks to VW Assistance) who despite not carrying coolant did a pressure test and confirmed OK to drive (my mother actually had some VW coolant at her house !) small top up & has been OK ever since. I think the coolant expands/contracts so if an extreme of temp can flag a warning if close to limit

[THR32]

Evening all,

Many, many thanks for all your responses - and sorry for the delayed reply.

After using the best part of half a bottle of coolant, the problem abruptly disappeared - so all your assurances that it's normal were very much appreciated.

Thanks

TH