Fabia coolant temp sensor - how to

[ap0gee]

Blatting up the M1 in SWMBO's Fabia, I noticed the temperature gauge was stuck to the left and wouldn't budge. It came back to life after we switched off the ignition to fill up with fuel, which is a telltale sign that the sensor's on its last legs. This can apparently lead to head gasket trouble and all sorts, so here's how to replace it:

NB: There is now a printer-friendly pdf version attached at the end of this post!

You will need a small screwdriver, and possibly a socket set, depending on the model of Fabia. The part number is 06A919501A, and cost me GBP26.28 incl VAT.

NB: DO NOT DO THIS JOB UNLESS YOUR ENGINE IS ABSOLUTELY STONE COLD!!!

1. Take off your engine cover. On my vRS, you just remove the oil filler cap and pull. On SWMBO's 1.4 MPi, you have to remove the dipstick, oil filler cap, and the two nuts shown:

2. The coolant temp sensor is here on a 1.4 MPi:

(Sorry, I've not done the job any other cars to say where theirs are, but I reckon if you follow the coolant hose along past the right-hand side of the engine, you ought to find it!)

3. Fortunately, as I was replacing the sensor on Mrs. Ap0gee's car, it's at the highest point in the coolant circuit, so I didn't have to drain the system. You might have to at this point...

4. Unclip the sensor from its plug, and separate the two:

5. Remove the circlip holding it in place:

6. Give the sensor a bit of a jiggle and it will come out:

7. The offending article:

8. Put the new sensor in, and put your car back together following the above steps in reverse order.

9. If you have access to VAG-COM, clear the fault codes. If not, the coolant system seems to work OK regardless, but warn your garage that it's been done, otherwise when THEY read the fault codes they may want to put in another sensor!!!

HTH

[bigdaddy]

I saw your year old post and thought you might be able to help. I have a bit of an emergency with my Fabia 1.4.

I bought one of these sensors from eby and it looked identical. I fitted it but the warning light stayed on. Then I drove it a few miles and the coolant warning light flashed and beeped and smoke came out of the grille.

I parked and walked 5 miles back home.

Should I replace the old sensor? Should I get some G12 coolant from somewhere just in case?

I've no idea if there is any serious damage done until I get back to the car.

If it is possible you could reply asap to david.callinan@btconnect.com I would be grateful.

Kind regards


David Callinan

[student_skoda]

I've just found this article too

The coolant temp gauge went to the left, came back to normal a few times but is now stuck at the left. The 'electronic engine management' light also came on, is this normal? If so will it go out when the sensor is replaced?

What is the resistance of the sensor when cold?
Thanks
Tim

[ap0gee]

Going to try and answer these two queries done in a one-er. Please be aware I don't know anything like as much some on here, so there may be other (better) responses...

Originally Posted by bigdaddy

I saw your year old post and thought you might be able to help. I have a bit of an emergency with my Fabia 1.4.

I bought one of these sensors from eby and it looked identical. I fitted it but the warning light stayed on.

When the sensor went on my wife's car, it didn't actually make any warning lights come on, it was just that the temperature gauge didn't work. AFAIK, the coolant warning light works off a different sensor, but you don't say whether this was the light that 'stayed on'... Was the the engine management light (see below)?

Originally Posted by bigdaddy

Then I drove it a few miles and the coolant warning light flashed and beeped and smoke came out of the grille.

I parked and walked 5 miles back home.

Should I replace the old sensor? Should I get some G12 coolant from somewhere just in case?

Was this the light that was on before? Or did the coolant warning light come on in addition to whatever light was on before? From what you're saying about 'smoke' coming out of the grille, could it have been steam? If so, I suspect there's a leak somewhere - possibly from around the sensor if it wasn't a good fit. If you stopped as soon as the warning light came on, you may be OK but you'd need to top up with coolant as you will have boiled some off...

Originally Posted by bigdaddy

I've no idea if there is any serious damage done until I get back to the car.

If it is possible you could reply asap I would be grateful.

Kind regards

David Callinan

If you have overheated the car (it does sound like it ), then there's a possibility that you may have damaged the heat gasket or even the head itself. You should be able to drive the car once you top up the coolant, but I wouldn't recommend taking it any further than the NEAREST garage - and if you've got breakdown cover, get it towed... I'm sorry I can't help more, but it's all a bit beyond my knowledge, I'm afraid...

Originally Posted by student_skoda

I've just found this article too

The coolant temp gauge went to the left, came back to normal a few times but is now stuck at the left. The 'electronic engine management' light also came on, is this normal? If so will it go out when the sensor is replaced?

What is the resistance of the sensor when cold?
Thanks
Tim

As I said in my response to David, there weren't any warning lights when it happened to my wife's car, but the other 'symptoms' suggest that the sensor's gone. If the sensor failure has caused the engine management light to come on, replacing it should make the light go out I think, but the fault code will still be stored (hence what I said in the original post). I'm afraid I don't know the resistance of the sensor though...

[student_skoda]

Hey, me again

When I used my car today (first time since me and my Dad have a look at the sensor) and the coolant temp gauge worked intermittently. When i parked for work the gauge was working but the 'electronic engine management' light was still on. However when i left work later the gauge still worked but the management light was not on (was on at start up so light still working). Does it have a long and short-term memory or something, so when a problem is fixed or fixes itself the light goes out but the code stays in the long term memory?

half way home the gauge stopped working, so its not fixed

I found this topic.
http://www.briskoda.net/forums/fabia...tuation/66771/

It all seems to be familiar (even same engine (1.4MPi) and one same reg (02) as one of the cars mentioned). Though when they sometimes say thermostat, do they mean the coolant temp sensor?

Is the coolant temp sensor used by the engine management system to control the reeves at idle when cold, etc?
My car has had some interesting quarks when starting at certain times (nothing series). Could this be connected?

Thanks
Tim

PS - I've found the resistances of the coolant sensor in my Haynes manual (they were a little hidden) If anyone wants/needs to know just ask

[ap0gee]

Originally Posted by student_skoda

I found this topic.
http://www.briskoda.net/forums/fabia...tuation/66771/

It all seems to be familiar (even same engine (1.4MPi) and one same reg (02) as one of the cars mentioned). Though when they sometimes say thermostat, do they mean the coolant temp sensor?

You're right - it does sound similar to the problems you've been having! As regards thermostat / temp sensor, the sensor sits within the thermostat housing. Since doing my technical guide, I've heard from a few people that it's not much more difficult to replace the 'stat housing (sensor and all) in one go, as the thermostat can sometimes fail at about the same time as the sensor, so you can "kill two birds with one stone". Plus, you can get all the bits as a pack from the dealers, for not much more than just the sensor. I think Fordfan posted somewhere earlier on the thread how to do it. As regards your other queries, I don't know enough about the diagnostic system to say whether fault codes have an "expiry". Certainly, when the EPC light came on on my wife's car, it stayed on after I switched off and back on again, but wasn't there the next day and hasn't returned since. You can always see if there are any members near to you who will give your car a check-over with VAG-COM (for a few beer tokens, of course! ) As for the sensor controlling revs etc, it certainly does (as do a number of other things, too!). Obviously the engine is more efficient when warm, so amongst other things, it will provide input for the equivalent of the choke on a carburettored car. As the engine may think it's cold when it's actually warm, this will affect the fuelling and thus the performance...

HTH

[ilpap]

Originally Posted by ap0gee

Blatting up the M1 in SWMBO's Fabia, I noticed the temperature gauge was stuck to the left and wouldn't budge. It came back to life after we switched off the ignition to fill up with fuel, which is a telltale sign that the sensor's on its last legs. This can apparently lead to head gasket trouble and all sorts, so here's how to replace it:

NB: There is now a printer-friendly pdf version attached at the end of this post!

You will need a small screwdriver, and possibly a socket set, depending on the model of Fabia. The part number is 06A919501A, and cost me GBP26.28 incl VAT.

NB: DO NOT DO THIS JOB UNLESS YOUR ENGINE IS ABSOLUTELY STONE COLD!!!

1. Take off your engine cover. On my vRS, you just remove the oil filler cap and pull. On SWMBO's 1.4 MPi, you have to remove the dipstick, oil filler cap, and the two nuts shown:

2. The coolant temp sensor is here on a 1.4 MPi:

(Sorry, I've not done the job any other cars to say where theirs are, but I reckon if you follow the coolant hose along past the right-hand side of the engine, you ought to find it!)

3. Fortunately, as I was replacing the sensor on Mrs. Ap0gee's car, it's at the highest point in the coolant circuit, so I didn't have to drain the system. You might have to at this point...

4. Unclip the sensor from its plug, and separate the two:

5. Remove the circlip holding it in place:

6. Give the sensor a bit of a jiggle and it will come out:

7. The offending article:

8. Put the new sensor in, and put your car back together following the above steps in reverse order.

9. If you have access to VAG-COM, clear the fault codes. If not, the coolant system seems to work OK regardless, but warn your garage that it's been done, otherwise when THEY read the fault codes they may want to put in another sensor!!!

HTH

BRAVO THIS IS VERY GOOD

[shrump]

Good info on the temp sensor as our 1.4MPi is just starting to play up with engine revs at idle & intermittant temp gauge operation.
Have been wondering whether rev probs due to engine management system? Will try replacing sensor first.
On another note regarding the EPC light. Ours recently came on with no apparent cause i.e no loss of power etc. Turned out to be the brake light switch. Replacement part 8 quid from dealer.
No need to reset as it sorted itself out when engine turned on (self check)
cheers
shrump

[student_skoda]

I found some 'qurks' with my engine when the temp sensor was faulty that cleared up when it was replaced.
One of these was starting a warm engine after a stall, the engine would need revs after the start or the engine would stop again

Tim

[yo hmy]

My coolant temp sensor is on perminantly however the temperature is where is should be i have replaced the sensor to no evail. i took it to a garage and the man put it on the computer the 02 sensor was broken, this was fitted and the light went out horay, then comes today the sensor is back on and im angry Bloody car

any help would be great

ps. my lights are flickering also is this a electrical problem or a short circuit ?


many

[ap0gee]

Originally Posted by yo hmy

My coolant temp sensor is on perminantly however the temperature is where is should be i have replaced the sensor to no evail. i took it to a garage and the man put it on the computer the 02 sensor was broken, this was fitted and the light went out horay, then comes today the sensor is back on and im angry Bloody car

any help would be great

ps. my lights are flickering also is this a electrical problem or a short circuit ?


many

When you say 'flickering' do you mean like a candle, or do you just mean dimming slightly from time to time? A bit of dimming is normal due to the amount of power used by the power steering, however an actual flicker is usually the result of a faulty steering angle sensor. Have a search on here for it (not to be confused with the 'yaw angle sensor' that's part of the ESP system!)

Fixing this might help get rid of your warning light too!

HTH