Temp Gauge Or Thermostat

[baggie]

Hi All. A while ago, after years of the temp gauge running at 90 solidly (once it had warmed up that is!), I noticed that the gauge dipped quite suddenly to about 70-80 but then returned to its normal 90 just as quickly, this was fairly unusual as it normally just stayed on 90, but it didn't do it again for ages so I didn't think too much of it.

 

Recently, it has started doing it more often so that now it happens on most longer journeys.

 

The car warms up from cold and the temp gauge behaves normally until it gets to 90, after it's been running at 90 for 10mins or so, it starts to fluctuate intermittently, although it never goes above the 90, but the dips have become bigger and recently it has gone down to 60 or so before coming back. It sometimes feels like the heater is less efficient when it is doing this but I don't know if this is just me.

 

I suspect it need a new thermostat or could it be the temp sender. Are these easy enough DIY jobs on a MK2 1.9TDi? and if so are there any guides with photos so I know what to look for?

 

Anyone experienced this or have any advice?

[Mirez]

Temperature sensor failing - reasonably common but getting the right ones a bit tricky!

[baggie]

Temperature sensor failing - reasonably common but getting the right ones a bit tricky!

 

thanks for that.... is changing the temp sensor easy enough? once you have the right one that is

[Mirez]

Not fitted mine yet, its next weekends task! Its only held with a circlip so should be easy to swap, getting to it might be another issue but again I'll have to let you know!

[baggie]

Not fitted mine yet, its next weekends task! Its only held with a circlip so should be easy to swap, getting to it might be another issue but again I'll have to let you know!

 

 

I've just found a couple of decent articles in the FAQs with some pictures and guides if these are of any use to you

 

http://www.fordgalaxy.org.uk/ford/index.php?showtopic=7886

 

numbers 49 & 56

 

best of luck!

[billywizzo]

Hi

It is a bit tricky as you are doing it most by feel.

A small flat blade screwdriver is great to get the clip out with, just get the blade into the bottom of the clip and pull it down.

It is probably fitted from the bottom up but I refitted mine from the top.

Just make sure you don't drop anything.

Also you will need to get some coolant fluid as you will need to top it up.

Once I got mine out, I took it with me to the auto factors to make sure I got the correct one.

It is just a pain to get to but fairly easy once you can get a hand to it.

 

Bill

[FLENG]

Hi All. A while ago, after years of the temp gauge running at 90 solidly (once it had warmed up that is!), I noticed that the gauge dipped quite suddenly to about 70-80 but then returned to its normal 90 just as quickly, this was fairly unusual as it normally just stayed on 90, but it didn't do it again for ages so I didn't think too much of it.

 

Recently, it has started doing it more often so that now it happens on most longer journeys.

 

The car warms up from cold and the temp gauge behaves normally until it gets to 90, after it's been running at 90 for 10mins or so, it starts to fluctuate intermittently, although it never goes above the 90, but the dips have become bigger and recently it has gone down to 60 or so before coming back. It sometimes feels like the heater is less efficient when it is doing this but I don't know if this is just me.

 

I suspect it need a new thermostat or could it be the temp sender. Are these easy enough DIY jobs on a MK2 1.9TDi? and if so are there any guides with photos so I know what to look for?

 

Anyone experienced this or have any advice?

 

 

i had a very similar problem

i noticed mine doing the same, and presumed it was the thermostat opening

 

then i noticed the heaters

when i drop the kids off at school the car warmed up like it should

but then a tickover it would cool off a bit and not really get any warmer, then when i continue to drive the heaters would be fine once again, seem very strange and ive had similar problem before with head gasket and these vw diesels

 

have a look see if there is excess pressure in the expansion tank

run the car for a bit say 5-10 mins then take the cap off, it should have a little pressure in there not alot, mine seemed to have a bit more than normal so i sold up. if it has pressure when the car is stone cold then that is a strong sign

 

do you ever have to top up the water?

 

it could be simply the thermostat opening like it should (at 90) letting cold water circulate as its letting the hot water out

you mention the heaters being less efficient when it does it this but i would guess thats pretty normal if it only happens for a few seconds

if the heaters are good the rest of the time i would say theres nothing wrong in my opinion

[baggie]

Yeah the heaters were fine if you asked them to heat but the climate control didnt seem to control the heat as it used to but this was intermittent

[chrispb123456]

Yeah the heaters were fine if you asked them to heat but the climate control didnt seem to control the heat as it used to but this was intermittent

Hi there

Has the problem gone away since the warmer weather has arrived or do you still have the fluctuating temperature gauge, maybe faulty temperature sensor? also does your booster heater work in the colder weather (below 10 deg c, also electric coolant pump (run on pump) check for humming in engine compartment when switching off engine, pump should stay on for 2 to 3 minutes then shut off.

 

May be worth doing a scan with vagcom see if any fault codes stored for aux heat, and aircon.