TDI 6n2 Fuel Gauge Probs Earth/Sender

[Polo*]

Fuel Gauge always shows full or 3/4. what could this be?

many thanks

[alexperkins]

Starter is on the back of the block, and is removed by three bolts. Quite easy to get those out

The hardest part is undoing the B wire on the back of the starter from the battery as access is awful.

As for attempting to fix it, disassembly is not a good idea. Replacement is really your only option as the casing is pressed on. They dont break apart like the picture shows At least not with any ease.

Sometimes a simple remove, grease of the shaft and refit will resolve the issue.

[vw55raz]

hi mate, I had the same problem on my one as well. Changing it was easy. disconnect battery first, and just simple remove and replace. The bolts are pretty long though and u might need deep sockets to take them out.

FYI if u need techinal help for the Engine, get the next model up haynes manual, as they have the same 1.4 TDI AMF engine in those

btw, nice car

[alexperkins]

You wont need deep sockets lol

You can get it out with a normal 13mm socket on an extension or just a 13mm spanner!

[vw55raz]

You wont need deep sockets lol

You can get it out with a normal 13mm socket on an extension or just a 13mm spanner!

oops my bad. i remember i had to use deep sockets for something in the engine bay once.

[alexperkins]

ill forgive you

[Polo*]

excellent thanks guys. i know not much about engines tho. so when you say back of the block. is that over behind the oil cap and down behind?
if i dont have success opening the motor. i will get a replacement. but at least i'll know how to replace it myself hey

also can i access this all from under the hood. or will i need ramps stands etc?

gotta remove the fuel sender tomo too and see why thats not registering properly either. always got a 3/4 to full tank...

cheers mate. i will get the other book too then.

[alexperkins]

Back of the engine IE were you reach your hand down behind towards the inside of the car direction

Also on the topic of attempting to open it - starter motors draw around 300 amps on starting. If you dislodge something or if it doesnt go back together 100% properly, you could end up with a vehicle fire

Youll need to be underneath for best access. To undo the wiring is very difficult from on top

As for 3/4 of a tank all the time, thats due to a grounding problem on your fuel sensor.

[Polo*]

thanks so much for this info. maybe i will leave the starter motor till when i have a spare available. and just swap them. sounds the best bet now. have a vw breakers in angmering im gonna hit up when i get paid.

what would you advise to do with the fuel sender. would the grounding be the wiring coming out of the sender unit? as i noticed it has 4 wires. was thinking retrace the wire make sure it not exposed anywhere. vw quoted me 400+ for the whole unit replacement.....

thanks again mate your help is much appreciated.

regards James.

[alexperkins]

The fuel sensor fault has come up before - id do a search on the forum.

Its often due to the clock grounding, but it can be due to other things. The wiring out the sender unit will probably ground nearby - follow the Brown wire, but id say the fault is more likely to be elsewhere.

[Polo*]

cool i will do some digging on here and web. thanks again for your help.

[alexperkins]

no worries

[Polo*]

Okay from my findings re: fuel gauge. i have come up with.

1. Gearbox grounding strap. (can effect Clocks/Gauges)
Where is this exactly located and what does it look like? screwed to the gearbox front (is that interior or exterior wise?)

2. Negative Battery grounded properly to chassis

3. Gearbox drive sender (seems most likely, but.... my Speedo is working fine so am unsure if this is the cause..)
Where is this exactly located and what does it look like? possibly this in photo?


also noticed for the first time today that after i started the car the gauge sat on empty with the empty symbol on. until i was 5 mins into my journey then it shot up again lol.

again thanks so much for any help. this forum is awesome for ppl like me in similar situations.

[alexperkins]

Gearbox grounding strap. Theres a big black wire thats on the front of the engine underneath the top radiator hose (its relatively obvious to be fair)

Battery to chassis - again, ensure the black wire from the battery is connected properly to the chassis

Gearbox drive sender. this is located on the back of the gearbox. You can access it from underneath. It sends the signals to the clocks for speed and few other things, and yes its that in the photo.

[Polo*]

ok update on this. still got the problem. but now its always stuck on half a tank/or not responding at all and on 0 but with no empty light... i checked the earth-chassis earth and also added a second ground to the chassis. i had problem finding the other ground wire near the engine. to many wires lol. an have not got any ramps to remove under-trays and find the gearbox sender. but im gonna ask vw to have a look on the service this saturday.
i have some O ring terminals coming which i plan to splice the earth wire from the sender and ground it on the sender black over cover screw aswell.

just found this this morning and am gonna give it ago. (Cleaning fuel sender guide)
http://forums.tdiclub.com/showthread.php?t=282173

just an update. and a reference for anyone in a similar situation.

regards James.