Is this what I need?

Radiator Fan Temperature Switch - £6.50

Bumping for justice-

I had overheating problems with my 6n today....seems to only be the thermostat that I need - but after reading this it seems that changing the temp. sender might be benificial aswell. For the 1.4 Cl 8v AEX engine I'll need:

"17623 THERMOSTAT PO 1.4 60 BHP 7/95" £6.50

I cant seem to find the temperature sensor/sender on GSF, can anyone confirm thats the right 'stat and offer up a part number for the black/blue sensor?

Thanks

edit:

"93494 TEMP.SENSOR-4 PIN BLK/YEL PO" £8.50

This looks like the one but it doesnt look like GSF do the black/blue one (would the one for the 1.6 fit possibly?), is the black/yellow sensor crippled in comparison?

Edited 21 August, 200818 yr by Alexander III

hi everyone I'm new on here just purchased a 1997 p reg mk4 6n 1.6 auto gl polo, was searching the forum and found this topic.

so far on half a tank i have done 120 odd miles which wasnt what i bargained for as i down sized from a fiat stilo (dont ask i know fiats are piece of .......... lol)

the car itself runs fine but the fuel consumption is a worry as its 40 quid for a full tank.

so you guys believe that this temp sensor shall do the trick.

by the way with regards to some saying that the car at times may not run correctly what kind of signs would occur?

thanks appreciate it

^^^

this aint your problem if the car runs fine.

might be a flue sensor or something giving false readings

so with all the starting troubles i have been having figured i would try this. pulled the old sensor out to be greeted with a force of coolant coming at me :( by the time i had the new one near the hole it had drained the lot over the floor :( plus it looks like the new one isnt fitting as when the clips back in it wiggles and there is water leaking from the joint :(

so with all the starting troubles i have been having figured i would try this. pulled the old sensor out to be greeted with a force of coolant coming at me :( by the time i had the new one near the hole it had drained the lot over the floor :( plus it looks like the new one isnt fitting as when the clips back in it wiggles and there is water leaking from the joint :(

did you get this sorted in the end?

so with all the starting troubles i have been having figured i would try this. pulled the old sensor out to be greeted with a force of coolant coming at me :( by the time i had the new one near the hole it had drained the lot over the floor :( plus it looks like the new one isnt fitting as when the clips back in it wiggles and there is water leaking from the joint :(

did you get this sorted in the end?

I just fitted mine, and i got the seal from VW, £34 for both but when taking the old temp sensor out i couldn't see a seal, so i just put the new sensor in, it DOES wiggle about, but i have no water leaking from it, where do you put the seal, or where does it go, is it sat in a recess in the black plastic bit attatched to the engine?

Please someone help me with the wiggling sensor or where the seal goes!!!

Neil

also the old sensor i took out had a yellow colour band on it and the new one is blue?? and the part numbers are different and they both look different..

my new one looked like this...

and the old one looked like this..

please help, have i got and fitted the right one??

Neil

also the old sensor i took out had a yellow colour band on it and the new one is blue?? and the part numbers are different and they both look different..

my new one looked like this...

and the old one looked like this..

please help, have i got and fitted the right one??

Neil

the right is that on second pic

you mean the one i should have got is this one..

357919501A

temperature sender / 20MM / AEA,AEV,ADX,

for coolant temperature gauge / 4 pin / AEE,AGD,AFH,

/ black/yellow / AHS,AER,AEX,

and / AHG,AKU,AKV,

electronic control unit / ALL,ANX,AFK

looks like VW have given me the wrong one, grrrr

Edited 30 July, 201016 yr by Broody

Where is the sender on a 16v? I cant find it.

Just to add to what James initially posted at the start of this thread, he is bang on with this fix

Here's my story on a 1.0 polo 99V

Failed it's MOT on high CO at increased revs, should be less than 300ppm, was at approx 500ppm, all other emissions good

Car had poor fuel consumption

Temperature indication on panel was sub 90 degrees, around the 75 mark and sometimes got to 90 but always fell back to 70/80 degrees at some point

Didn't run too bad, had performance but revs hung at 1200/1500 and didn't want to go to idle speed when throttle released, although would eventually get there

Just didn't run as it should, heater output was hot but not that hot

Was it the ecu, thermostat, lamda, throttle body etc etc?

Did start by changing the throttle body with secondhand one from Seat car, but no change

Did a bit of reading on the web on how the ecu works and read James's thread, and it all makes sense

On start up the ecu works on an open loop control, it basically gives fuel and air in a ratio of 9 to 1 very rich, just like having the choke out on older cars, and makes the car run Ok when it's cold but the rich charge cools the engine as things warm up

As the car warms up, the ecu eventually sees a signal from the ECU temperature sensor that its at some figure, say 70 degrees and at that point the control system goes into closed loop control as the lamda kicks in and monitors the O2 in exhaust and trims the air flow back at throttle valve to give stoiciametric mixture of 14.7 to1 and achieves the requisite emissions of less than 300ppm CO.

So I changed the temperature sensor, it being the yellow 4 pin one (taking out the original VW yellow sensor) and fitted a new locally obtained part from Motor factors

Started the car and let it warm up, took it out for a run and bingo, temp indication is bang on 90 degrees and holds no matter if heater full on. This is because the car is now running leaner mixture and that means engine generates more heat. The heater output is very hot on full, you cannot hold your hand in front of vents for long

After reving or dipping clutch etc the revs immediatly drop to 800 ish, no hanging about or fluctuations

If you have any of the above symptoms, have a good think on whats happening before spending money on new parts

In this case the ECU side of the Temperature sender was at fault, the ECU not receiving the signal to switch to closed loop control, cost £16 to fix

Is there a way to check the readings from this sensor? Is it a case of using a multimeter on the terminals or will something like VAGCOM give this info ? It would be nice to prove it is this item that has faield before replacing it.

James,

Big thank you for posting the pics, couldn't remember how the clip went on, so that pic helped a great deal, job done :)

so with all the starting troubles i have been having figured i would try this. pulled the old sensor out to be greeted with a force of coolant coming at me :( by the time i had the new one near the hole it had drained the lot over the floor :( plus it looks like the new one isnt fitting as when the clips back in it wiggles and there is water leaking from the joint :(

did you get this sorted in the end?

I to just changed mine and was greeted with coolant pissing all over me, just be careful people when changing as any coolant stored will come out.

Mine does drip and is a little loose... so will need to get new seals, It's a lot harder to get to on the 16v!

Is there a way to check the readings from this sensor? Is it a case of using a multimeter on the terminals or will something like VAGCOM give this info ? It would be nice to prove it is this item that has faield before replacing it.

6N ECT Testing by nige8021, on Flickr

Edited 14 January, 201214 yr by nige8021

Thanks for that I will have to give it a go as my car doesnt even get warm after 100 miles yet my wifes 6N is like a furnace in less than a mile :-D

Just to note that in the first description with the pic, after unclipping the metal clip and plug, you need to lever out the black plastic curved clip that he is pointing at in the pic (not rubber, as that got me confused), get a small screwdriver and put it under the little gap (where it curves the most) and lever the plastic clip up. Like said, the coolant will pour out and not really possible to plug it enough with you thumb/finger and also when fitting the new one in place. Might be an idea to put a plastic jug or bowl underneath to catch most of it. You'll certainly need to top some up anyway.

One question, does the sensor need to be fitted in any particular position? As, as the end of it is round, there seems to be no locating bit. I just positioned it to what seemed to match where the connecting plug seemed to go.

Just hope this sorts out my cutting out and erratic rev counter!

Edited 3 July, 201214 yr by Aquablue

I did the same, just matched it to my wiring plug. Do make sure you have topped your coolant up afterwards. Then check again in a couple of days as it may have dropped due to any air that got in whilst you were fitting the new one.

as so many of us mk4 lot are suffering from, high idoling, engine cutting out and shite mpg. i thought id try to help.

Now i no theres a thread around which says clean the throllte body and reset the ecu.(i did this, and nothing happened ) so personally id say dont waste time and just get you are self down vw as for a temp sensor for a mk4 polo, they will no exactly what you want. its 29 quid and well worth it.

i havnt actually got pics of me doing it as I'm only writing this cos 2 of my mates have asked about it but i can show you where it is and how to do it

this is where it is

now all you have to do is, un clip the electrical clip. then pull out the rubber seal thing which my weird looking fingers are pointing at lol.

now pull the sensor out ( pull down)

and quickly plug it with your finger as some coolent will come out but not enough to worrie about.

then its a reverse process, put the new sensor in, slide seal back in, and clip the electrical clip back on.

job done. it will start first time and idol at 900 rpm

p.s

the new sensor will look nothing like the old one. i figure its because vw replaced it with a better one.

and also remember if something goes wrong, its not my falt this is just a simple guide of what i did.

Hi James,

Thanks for the fitting advice, just replaced the 4 pin temp sensor on my daughters 1.6 Polo M reg, easy job thanks to your help.

Unfortunately the cold starting problem hasn't been cured, any other ideas ? I have replaced plugs, leads, distributor cap and rotor arm. It runs fine when hot but refuses to start when cold except when garaged overnight then starts normally.

PS Battery is fine

Thanks

Rog

Could anyone tell me if this is the likely cause of low revs / engine cut-outs on my 2005 1.2 Twist (9N, 12v, code BME)?

Sometimes, after starting the engine, the revs will drop suddenly after a few seconds idling - sometimes the engine cuts out, sometimes it kicks back into life. It seems to happen only after I've used the car already that day. I've also had a problem with engine cut-outs when the car's warmed up but I'm travelling at low speeds (clutch down round a mini-roundabout; reverse parking).

Any help or advice would be much appreciated. Thanks.