Hey all,

I "THINK" this is the right forum for my 2001 Octavia VRS? (if not appologies)

at the moment both the engine light and the traction light are on and will keep coming back on if I clear the faults on the ECU.

This is what comes up read I read the faults with my elcheapo reader:

Current Fault Log

------------------

P0103: Mass or Volume Air Flow Circuit High Input

Pending Fault Log

------------------

P1296: [seat/Audi/Volkswagen] Cooling system malfunction

I think the issue is the Engine Coolant Sensor? I understand this is an easy enough job to do yourself? From this forum i found this part number, im wondering if you can confirm if this is the right part and also if you think this is likely the issue.

I suppose it could also be the MAF at fault but I had that cleaned recently.

Part I found:

http://www.ebay.ie/i...#ht_1443wt_1396

Also would this be the MAF to get (yes im going to chance a cheap one first);

http://www.ebay.com/itm/150544258711?item=150544258711&pt=Motors_Car_Truck_Parts_Accessories&cmd=ViewItem&hash=item230d231697&vxp=mtr

Thanks for help!

Edited 26 April, 201214 yr by fionny

Yep that's the part. Make sure they offer a guarantee though as those ebay coolant sensors don't always work. Genuine part is £29 from a dealer.

The first fault does sound like a MAF issue, I would check the multiplug and wires are ok, unplug it from the MAF and check the terminals are all ok and not corroded and maybe apply some silicon electrical contact grease before you go buying another MAF.

Yep that's the part. Make sure they offer a guarantee though as those ebay coolant sensors don't always work. Genuine part is £29 from a dealer.

The first fault does sound like a MAF issue, I would check the multiplug and wires are ok, unplug it from the MAF and check the terminals are all ok and not corroded and maybe apply some silicon electrical contact grease before you go buying another MAF.

Cheers will check that tonight, bit of a pain as I need to get my car tested and they now fail for any warning lights whether mission critical or not.

That part is just the sender I see is that what I actually need or do I need the sensor itself?

Edited 26 April, 201214 yr by fionny

Sensor/sender same thing.

You should really replace the U-shaped plastic clip and rubber o-ring seal that hold the sensor in place (another few quid from a dealer) but it looks like that ebay one comes with those.

Sensor/sender same thing.

You should really replace the U-shaped plastic clip and rubber o-ring seal that hold the sensor in place (another few quid from a dealer) but it looks like that ebay one comes with those.

Thanks, I have ordered the part now will see do the ECU faults stay cleared when I fit it, otherwise its on to change the MAF (i reckon it probably is fooked as my fuel efficiancy seems bad these days)

A knackered Coolant Temp Sensor can affect your fuel efficiency because if the ECU thinks the engine is cooler than it really is it injects more fuel. Mine was down by about 3-5mpg with a dodgy sensor.

A knackered Coolant Temp Sensor can affect your fuel efficiency because if the ECU thinks the engine is cooler than it really is it injects more fuel. Mine was down by about 3-5mpg with a dodgy sensor.

Here is hoping so Will let ye know how I get on once i get it fitted, thanks for all the replies!

I got the part today, Ive searched the forum for a guide on swopping this out but could only find links to a thread that doesnt exist any more, anyone know of a quick guide?

Thanks,

PS Its AUQ engine (2001 vRS) and im a total noob at this stuff So tools needed etc would be a big help.

Edited 2 May, 201214 yr by fionny

link

you'll want to change it when the engine is cold. the colder the better (hot engines cause coolant loss - stone-cold ones will cause absolutely none)

link

you'll want to change it when the engine is cold. the colder the better (hot engines cause coolant loss - stone-cold ones will cause absolutely none)

Ummm...

You'll want to change it when it's cold, hot engines have hot coolant and it comes out all over your hand, even more so when picking out the stinking old o ring which usually stays stuck in place.

Even when stone cold and unused for days there will still be coolant in the pipes, the header is above this as is the top of the rad, so you are going to lose coolant, well it is and you do on the TDI. If you're lucky you won't lose too much. Check the header tank, probably after running the engine for a minute or so and see where the level is. If it needs topping, use the right stuff, pink not blue, rating I can't recall but someone on here will.

Tom

Edited 2 May, 201214 yr by tomsimmons

Thanks guys, how long should the car be left idle approx for the coolant to be of a safe temperature?

Even when stone cold and unused for days there will still be coolant in the pipes, the header is above this as is the top of the rad, so you are going to lose coolant, well it is and you do on the TDI. If you're lucky you won't lose too much.

coolant is always in the pipes (no air whatsoever). it's pressure that makes the difference (hot -> expanded)

Thanks guys, how long should the car be left idle approx for the coolant to be of a safe temperature?

got mine out twice [once before changing, to verify it's a fake/old one]. on my first attempt the car sat still overnight. no coolant loss here.

on my second one it had the chance to cool for around 2.5 ~ 3 hours. lost one cup of coolant because of it. [that's about the maximum amount you'll lose]

think about the ~90 degrees of the coolant and you'll know why you'll want to let it rest

Edited 2 May, 201214 yr by za_killer

Well sadly the Coolant Sensor didnt make any different (was already replaced it seems as it was green), still getting the same 2 errors. So now its on to the MAF I guess?

Is the MAF in the VRS the same as in the standard Octavia's? Would consider getting one from a breakers if so.

This one has a 12month warranty on Ebay worth the punt for the money?

http://www.ebay.ie/itm/SKODA-1-8T-MASS-AIR-FLOW-METER-06A906461L-06A-906-461L-/300703824707?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item4603583b43#ht_4073wt_1163

Edited 5 May, 201214 yr by fionny

Unplug the maf if it runs the same then its ok, if it runs better then its at fault

Unplug the maf if it runs the same then its ok, if it runs better then its at fault

Will plug it out so and see how i go. Im kinda confident its the MAF alright, given I have the traction control light on aswell and a bit of googling indicated that was related.

ASR light indicates a MAF fault. MAF faults will not trigger coolant system issues

related to the CTS: maybe you had a ebay aftermarket green one (aftermarket ones are crap, always buy genuine ones). have you erased the fault code memory ? if so it's probably a wiring fault (check the multiplug)

I have cleared the codes and it comes back consistently, We cleaned the plug on the coolant sensor when I changed it.

to double check your CTS you could log the coolant temperature in vcds whilst keeping an eye on your temp gauge. the CTS has 2 feeds, one for the dash, one for the ecu. if the sender is brand new (working) the values should be pretty close (you can expect the needle to rise slightly different than the values read in VCDS, but once fixed at 90 the VCDS should read about 90~94). faulty CTS usually feed the ecu with lower (10 degrees or more) values than the dash. ex: my dash would read 90 while my ecu would think it's around 72...

this will point you towards a wiring fault or a bad CTS (if it's not genuine) if that's the case. i've got a pin diagram for the separate feeds of the multiplug on the CTS. if you want to measure the inner resistance of the sender i'll post it.

With vcds you are able to check both ecu and dash temps, not at the same time but it shouldn't change much in the seconds it takes to go between them lol

Okay ye are gone way out of my league, im a total noob when it comes to this stuff... I use an app on my phone called torque to check the faults etc,,, now this can read dash stuff. If the coolant is not related to the MAF in the least then the wiring must be foobarred because i find it hard to believe i had 2 faulty sensors. Im going to change the MAF anyway and see what comes of that but if its wiring then ill prob end up in a garage. Unless its a relativley easy job, got a few friends who love stuff like that.

With the torque app select the engine temp, think it reads from the ecu tho not 100% sure.

Have you enabled the speech function? If you do it on self scan then see when the fault occurs while running?

Will that Raf_

As for the MAF I think the car is nearly running better without it plugged in, I assume this would indicate its most definitely faulty and probably sending bad readings or something?

As for the MAF I think the car is nearly running better without it plugged in, I assume this would indicate its most definitely faulty and probably sending bad readings or something?

Yep that's usually the case.

I don't know if Android Torque will do MAF readings but if it does, post your MAF reading at idle up on here and there are other VRS owners with Torque who should be able to check it against theirs.

I know the MAF reading at wide open throttle on a standard VRS should be about 150g/m2 but I can't remember what it should be at idle (...I thiiiiink it's 30).

If you buy an ebay MAF do get one with a warranty as ebay parts don't have the best track record.

Was thinking of chancing this one:

http://www.ebay.ie/itm/SKODA-1-8T-MASS-AIR-FLOW-METER-06A906461L-06A-906-461L-/300703824707?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item4603583b43#ht_4073wt_1163

It says it has a 12month warranty so worth the punt i think as my funds are EXTREEMLY limited :p

Been looking up the coolant error and it seems the next likely stop is the thermostat which is cheap so gonna pick one up with the MAF:

http://www.ebay.ie/itm/AUDI-A3-A4-A6-TT-THERMOSTAT-TSTAT-O-RING-SEAL-GASKET-050121113C-NEW-/180829559285?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2a1a4819f5#ht_3140wt_1163