Engine speed sensor fault (16706)

[TimGti]

Our 6N2 1.4 Match threw up the engine check light & EPC light yesterday.

VAGCOM says 16706 engine speed sensor may need checking. Its thrown it on 3 or 4 times now over the last few months, goes away after a bit of driving each time.

Anyone know what this sensor does, where it is located, cost of replacing it, the importance of it etc etc.

Many thanks
Tim

[alexperkins]

http://wiki.ross-tech.com/wiki/index.ph ... 322/000802

Its the crank sensor - located on top of the rocker cover to the right hand side (under the plastic engine cover on top). Its about £18 for a new one, and tbf, they often fail.

[TimGti]

Thanks Alex, will take a look at this tommorow now I know where it is!

[emma_88]

Alex I thought the sensor on the rocker cover was the cam sensor?

I'm sure the crank sensor is to the back of the engine? I'm probably wrong though lol

[alexperkins]

I think it can be related to that sensor, though you may be right emma (im no where near home atm, so I couldnt check the service manual lol)

[TimGti]

Did you manage to check in your service manual which sensor my fault relates to Alex? Would be much appreciated as I dont want to buy the wrong one!

[D4v3o]

Hi Tim,

Did you manage to sort this problem, i know when i had a problem in the past with this fault code it turned out to be the Impulse Speed Sender located near the transmission housing. i'd have all sorts of problems related to this speed sensor where the car would judder and cut down to a limp home speed the EPC and Engine Managent Fault light would pop on.

I can't remember the exact part number but it cost about £80, i have the paperwork somewhere so can find out...

[TimGti]

Hi Tim,

Did you manage to sort this problem, i know when i had a problem in the past with this fault code it turned out to be the Impulse Speed Sender located near the transmission housing. i'd have all sorts of problems related to this speed sensor where the car would judder and cut down to a limp home speed the EPC and Engine Managent Fault light would pop on.

I can't remember the exact part number but it cost about £80, i have the paperwork somewhere so can find out...

The fault hasn't reared its head for a couple of weeks, but when it does its those exact symptoms. Power dies momentarily (not quite a stall but judder & cut in power), EPC & check engine light come on then youre restricted to 2k revs or below until you stop, turn off the engine and restart it.

I was told its the sensor under the engine cover on the right hand side that monitors engine speed. Cost about £28. I'll check the exact name of the sensor when I get home as I cant remember now.

Any info you have though would be great as it sounds like you may have found it to be a different fault than VW suggested to me ?!

[emma_88]

The camshaft sensor is located on top of the rocker cover to the right hand side (under the plastic engine cover on top) - As Alex said. The price for this is around £25

The crank sensor is located to the back of the engine, below the inlet manifold and starter motor (These need removed for the sensor to be removed / fitted!). The price for this sensor is around £50-£80.

I've bought both of these sensors so I know what you guys are going through.

[TimGti]

Just to confirm now Im home, the fault relates to the engine speed sensor G28, VW call this sensor the Camshaft position Sensor, fitted to the right of the rocker cover.

The fault has not reoccured in 2--3 weeks now so I have held out on buying the new sensor for the mo.

[D4v3o]

Yeah sure hold out, but if it does happen again i'd replace the camshaft position sensor (cheaper) before heading towards the £80 option, that may fix it.

[TimGti]

Just thought Id drag this up to conclude the thread for others who may read it. The symptoms have got far more frequent the last month or so to the extent that every time I drive it occurs. So today I have replaced the G28 sensor to the top right of the block just under the engine cover, (£28) and the engine check light has dissapeared immediately. Not been for a long drive, but it looks like this was the problem.

[TimGti]

Well, after replacing the sensor to the right hand side of the rocker cover, the fault disappeared for a year or so. Annoyingly the same symptoms have now returned with the same/similar fault codes.

16706 - Engine Speed Sensor (G28): No Signal
16705 – Engine Speed Sensor (G28): Implausible Signal

TBH I am still not sure which sensor the above (G28) actually relates to. VW told me the it was to the right of the rocker cover and I was happy that my fault went away for a while, but a lot of what I read on other engines says the 'speed sensor' is actually round the back of the engine, as Emma suggests above.

Does anyone know which of the two is actually the G28 on a 1.4 8v 2001 Polo?

Emma perhaps you could shed some more light on your experiences?

Tim

[alexperkins]

G28 I think youll find is the sensor on the back of the crankshaft below the starter motor

Its about £85 for a new one from VW these days.

[TimGti]

Thanks Alex. That's a lot of wedge for a sensor

The crank sensor is located to the back of the engine, below the inlet manifold and starter motor (These need removed for the sensor to be removed / fitted!). The price for this sensor is around £50-£80.

Emma/Alex - is this a DIY job? From under the car? Is it possible to get to it without removing the above? Sounds like a right pain

Seriously long shot. but I guess neither of you have any photos, or could take one to help me locate it please?