Crankshaft sensor removal

[pc759]

90 bhp tdi..
horrible startng problems just cant rely on it going after i've left it at moment, but it will bump off.I took it to a bosch agent last weekend and he said change the crank sensor.
Got one and have removed some ancillaries but it looks like i'll have to take off the oil filter housing to get at it.
To make matters worse the sensor is attached with what looks like a jagged edged nut somewhere in between . It certainly does not have flat edges and a 10 mm socket wont fit well enough, 9 mm too small. I have a good german socket set with torx sockets but they wont fit either im at a loss to say what i need to get it off can anyone help? i attach picture it is the small brown nut and you can just make out the edges im on about
anyone suggest special tools etc to fdo this one sorry about pic quality pretty tight in there

 

[Skipton01]

OK Paul,

It's listed as an M7 x 18mm bolt, with a 12-point (bi-hex) head. So, a normal hexagonal socket won't do the trick, you'll need a bi-hex socket. However, what size an M7 thread equates to head-wise, I can only guess as 9 or 10mm.

Cheers,

Mike

PS Why not get a new bolt from Audi and use it to find the correct socket? The part number is N 101 045 01 and it'll cost the grand sum of 29p!!

 

[pc759]

great i actually have one of those from an old set give it a go tonight