glow plug relay

[andwat]

tdi 105 - still having cold start issue, replaced all GPs, temp sensor - anyone know anything about GP relay/control unit? thanks. No codes showing on scan.

[phil miller]

when was your fuel filter last changed and how cold is it at yours atm?

[andwat]

filter done about 5k ago U think it could be to blame?...was 4 degrees this morn...possible weak battery? starter motor not turning over quick enough? glow plug relay?

[phil miller]

i was on the line of thought that if the filter hadnt been changed for a while it could be giving the issue (D5 volvo engines suffer from this in cold weather) but having only done 5k i dont think its that, and TBH 4deg isnt really cold, mine is a slow starter but my starter motor is sluggish (hots starts is a pita and takes ages) have you used a multi-meter to check power to the glow plugs? how old is your car and does the engine sound slow turning when you go to start it?

[andwat]

I'll maybe do the filter anyway, just to rule it out, only a tenner or so! Glow plugs are getting power ok yea, but when I turn ignition on in morn, I can hear relay click on and off (in sync with glow plug light on dash) but...only comes on for one second or less, then clicks off...I'm thinking they should be staying on for longer? People have mentioned 'extended glow period' that is supposed to kick in on colder starts....to best of my knowledge this is controlled by glow plug control unit/relay, priced today at £51...but no idea where it's located. It may also be working fine...Scan didn't identify anything so unsure! Gonna borrow new battery tomorrow night as Varta that in at moment is reading slightly weak...I'll get there eventually!!!!

[vwcabriolet1971]

You could try switching on & off to extend the glow plug relay period , this might reveal some clues.

[phil miller]

my 105bhp mk5 (04 plate) and my OH 57 plate 105 the glow plug light is only on for about 2 seconds, the golf doesnt use the glow plugs to start like older diesels, the glow plugs cut in and out to aid smooth running on warm up and emission control when the engine is cold, mine had all 4 glow plugs faulty for about a month last winter and she started fine each day, one thing you can do is go under the car and have a look at the under side of the start motor, if it looks a little rusty then your fault could be the starter motor (mine is and i do have to replace it) or you could use a camera and film the car being cold started that wayif you post it up on here i can say if its sluggish or not, trust me mine is sluggish and cranks over at about a 1/3 of the speed Rachels does

[andwat]

phil...i'll get it on video for you!