glow plug warning light came on flashing

**glennjarrett** · 19-07-2015,04:40 PM

I have a mk5 2.0l tdi ( BKD engine number ) a few days ago I nearly ran out of fuel ( but didn't ) put £30 diesel in and a few days later I was driving and the glow plug warning light came on flashing and the dash display said something like engine fault workshop so I pulled over the car was still running but tick over was a bit erratic so I switched the engine off and re started the car and everything was back to normal .
it has done the same a few times since but the last time it took quite a bit of cranking to get it to start up !
my code reader says the glow plugs and engine speed sensor G28 are showing faults
now I thought the glow plugs will only work when the temp falls below 6 degrees no need for them in summer but the engine management system probably runs a resistance check on the glow plugs at start up so possible wiring fault on either the plugs or speed sensor?

action taken so far

replaced the fuel filter and found the o seals that fit into the top of the filter was missing so I have been driving round without an effective filter !!!
changed the foot break switch

cant seem to find the engine speed (crank) sensor any ideas ?

**glennjarrett** · 19-07-2015,06:22 PM

just got back from a drive
and now it cut out on me completely whilst driving along, needed to start the car back up ?

**itavaltalainen** · 19-07-2015,06:53 PM

Where in the country are you?
I could have a look with VCDS.

**glennjarrett** · 19-07-2015,09:37 PM

Lancashire
just sent for a Bluetooth odb II module off ebay and will use with torque to see if I can find anything out but I still think its fuel related
will try some diesel injector cleaner also

**itavaltalainen** · 19-07-2015,10:57 PM

Lancs is a bit far from me, might be up there for work but only in a few weeks.

OBD2 is not very powerful, better to scan with VW specific tools.

**DMitch16** · 19-07-2015,10:57 PM

Possibly a wiring fault - check wiring looms on engine bay especially those close to hot surfaces, turbo heat shields etc, or a fuel tank lift pump issue maybe or one of a large number of other issues. A VCDS (VagCom) scan would be much, much better. ODB scanners often won't scan the areas of the ECU that would help you better solve your problem. You don't want to be changing the G28 just yet unless you are sure as it is below and to the right of your oil filter housing in a recess on the engine just before the gearbox bell housing and covered in pipes. The recess goes behind your flywheel and the sensor which is bolted deep inside with one bolt magnetically reads the spinning toothed "phase" ring.

**glennjarrett** · 20-07-2015,05:38 PM

done all 4 glow plugs this afternoon and checked the wires from plugs to round connector on side of engine and speed sensor all ok
not getting glow plug codes now
but still getting glow plug light coming on flashing with a chime from the dash and (engine workshop message on dash) still getting 16706 code
when the light comes on you get a chime from the dash and a message comes on the display the car doesn't loose any power but at idle it runs a bit rough turn the engine off wait a few seconds and on again and it seems to reset it
the light goes out
until it does it again each time it logs a 16706 g28 fault

**itavaltalainen** · 20-07-2015,07:19 PM

This is where VCDS would be useful - you can look at measuring blocks with that and see what might be causing the G28 fault.

**DMitch16** · 20-07-2015,09:01 PM

Also check any wiring for any exhaust / turbo sensors at the back of the engine as the turbo which is mounted upside down on the BKD (imo) below the manifold kicks out a lot of heat and it only takes a touch to melt wires.

Could be the G28 but it's not a dead cheap job unless you're doing it yourself.