I apologise for the lengthy post in advance, but here goes,

I've just spent the last three hours trolling through endless posts about rough starting on cold days, and the possible causes, but nothing seems to match my symptoms 100%.

I've had my Furby for nearly three years now, and starting was always perfect up until about November last year, then it started to have really rough starts, (and by really rough I mean it feels like the engine is trying to escape the chassis!), accompanied by huge amounts of thick blue smoke. This has gradually got worse to the point that it does it perhaps 4 out of every 5 starts.

I've tried all the usuals, changed the fuel filter, changed all four glowplugs, checked the supply to the plug harness, removed and decoked the EGR valve, checked the condition of all the small pipes on the vacuum control module and recently out of desperation bunged a bottle of Redex injector cleaner in it, I've even replaced the apparently healthy battery in case it wasn't turning over fast enough, but it still starts like a bag of sh1t3!

I have noticed that if it has been run within the last few hours, a majority of the time it will start cleanly, but at other times it'll start crappy when the engine is still warm!

It only runs rough for maybe 5 seconds, but its really annoying, and looks appaling with its very own smokescreen drifting down the street! A slight press of the throttle to just lift the revs to 1000rpm and it clears.

I've read quite alot of posts that have mentioned a 'relay 109', and I assume this is the relay you can hear click under the dash when the glowplug supply goes off? Could this still be the problem bearing in mind the loom is getting full battery power?

There are no warning lights of any kind, and once the rough idling stops theres no lack of power, and shes quite capable of leaving a big number '11' on the tarmac even with traction control on! Fuel economy is bang on at 53mpg on a motorway run holding 70mph so there doesn't appear to be a fuelling issue.

I suppose it only bothers me cos it doesnt sound or feel very healthy for the engine or its mountings in the long term! :|

Any other thoughts would be greatfully received!

Edited 18 February, 201016 yr by lostsoul82

Have you ran a diagnostics check on it? Maybe found someone local with Vagcom?

How does it drive generally when warm? Steady acceleration? Tickover ok? MPG normal? There's a few sensors that could cause bad running - cam & crank position sensors, mass airflow sensor. Hopefully a fault is logged to say what it is.

I haven't noticed any difference in the way it drives generally, just the rough starts. Acceleration is nice and smooth, MPG is pretty much bang on what Skoda quote for a standard engine (48 combined, 53 motorway), and the tickover once it has settled down is as smooth as can be expected from a diesel, even with one of those poly bushes from Awesome in the dogbone.

I dont know of anybody around here with VAG-COM, apart from the stealers, but I would be very interested to see if anything is logged. I have one of the little hand-held readers that plugs in the diagnostic port, suppose it wouldn't do any harm to try it!

The mass airflow sensor has been mentioned a few times in other posts, but that would affect tick-over and acceleration wouldn't it? :|

why didn't you get Awesome to do a diagnostic when you had the bush fitted ?

your handheld tester should work, my MAC tools one does,

another thought is, due to the blue smoke you mention, there could be oil running down a valve stem onto the piston crown, as to whether this would cause your misfire, not to sure

I fitted the bush myself, but then thats always an option as they're only 5 mins down the road, I'd forgot they have diagnostic stuff

I gave the code reader a shot, as far as its concerned there are no fault codes at all, so back to the mechanical stuff.

Just been out for a lap of the M60 to try and work that redex through a bit more, gave it a few WOTs from 60 to 70 just to open things up a bit. Its definitely burning it, cos theres a weird smell from the exhaust, kind of a weak aniseed odour!

It shuddered a little bit when I started it this time, just one misfire by the sound of it then it settled down.

The blue smoke is most likely oil thats getting past the piston that isn't doing anything during the misfire, I would hope its not wear related, its only just done 45K on a 54 plate!

I was wondering if I have a faulty injector, but then surely that would be playing up at all revs, not just starting?

I did alot of short journeys over the course of last year, and I dont generally drive it hard, maybe just the occasional WOT up a slip road to lose a beemer or something, maybe its clogged up from gentle driving?

If you feel up to it, take off the rocker cover and inspect the state of the cam/tappets if you can.

Faulty injector is a possibility.

my mate from work has a vag-com diagnosic program. i could get his number for u if you like. he would charge you but not to sure on how much wudnt be anywhere near the dealers prices and we work in withington manchester so not to far away from you. as for the oil sounds like stem seals as previously mentioned. how long have you had the car, has it been re-mapped and does it get driven hard from cold?????

Hmmm, nothing obvious jumps out at me and you seem to have checked/considered/changed the main items...

I'm fairly close and could run a VCDS scan if you like, see if anything comes up. Drop me a PM if you want to sort something out; might be able to arrange something for one night next week.

Steve

ste372, I dont drive it hard at all really, and even when I give it some its usually less than about 5 seconds, just to get up a sliproad or in a gap for a junction etc. No it isn't remapped, infact the only thing on the engine side that has been changed is the front mounted intercooler, in anticipation of said remap! I've never driven her hard from cold. Visually it doesn't use any oil at all either, which I'd have though would be noticeable after 6 months. Though like I've said I'm willing to consider anything now, if I run out of ideas completely I'll start looking at the more involving stuff!

Wardy, yeah, thats the thing, I've spent ages on her over the last few months trying everything that even mentions rough starting, the only thing I haven't tried is changing the relay for the glowplugs, on account that I cant actually get to it without destroying the dash I dont think, but I've even tested this and it appears to be supplying the plugs with full battery power as its supposed to.

Just a thought, is it possible the relay breaks down electrically when its under load, i.e. connected to the plugs? I've heard they can have dry joints in them, which would cause issues under load from increased resistance if my electronics memory serves me correctly? Cos I've only tried it with the tester stuck in the sockets. Hmmm................

I may well take you up on the VAC COM if I dont get it sorted this weekend, cheers.

The blue smoke on start up is usually associated with oil getting into combustion chamber, fire the engine up, a healthy blip of the throttle and the smokes gone. Valve Stem Oil seals are 90% of the culprits. Used to be very common on the 1st. Ford OH cam engines and was a yearly ritual to change the valve stem seals.

It's nothing to worry about and you can get them changed when you have other servicing work done, however it may mean the head will have to come, I not sure if the seals can be changed insitu, some engines it can be done and some not.

Strange that this the first time I've heard of a more modern VW diesel engine suffering from leaking/worn seals, lets hope it is just a one off and the materials used were not up to par when the engine was built.

As for an electrical or glow plug problem, no I can't see that this would have the same blue smoke effect. you would have other problems like difficulty in starting and black smoke, poor running generally.

If Vag.com is not showing faults then you would have to expect all is as it should be. There will not be a VAG.com fault codes for leaking Valve oil seals.

Just one other thing may be causing this, silly to ask the obvious, but are you using the correct oil.

Edited 19 February, 201016 yr by Soot1e

Hi,

My Vrs suffers from these same symptoms, blue smoke and rough startup for the first 5secs when its been started for the first time - its ok for the rest of the day though. One thing that I've noticed is that when the car is parked on the drive over night the startup is really lumpy and I get a cloud of blue smoke compared to when its left over night in the garage where its barely noticeable. Our drive is has an upwards gradient, so the nose of the car is much higher when parked on the drive compared to the level ground of the garage. Could this difference in gradient be causing more oil to weep into the combustion chambers?

Cheers,

Mike.

Edited 20 February, 201016 yr by mikehume

Hi,

My Vrs suffers from these same symptoms, blue smoke and rough startup for the first 5secs when its been started for the first time - its ok for the rest of the day though. One thing that I've noticed is that when the car is parked on the drive over night the startup is really lumpy and I get a cloud of blue smoke compared to when its left over night in the garage where its barely noticeable. Our drive is has an upwards gradient, so the nose of the car is much higher when parked on the drive compared to the level ground of the garage. Could this difference in gradient be causing more oil to weep into the combustion chambers?

Cheers,

Mike.

Oh thank god, its not just me!

Maybe its temperature related? How warm is your garage? 'Cos during warm(er) weather mine doesnt do it!

I've just come on to give an update actually after trying out a few things suggested on here.

Ok. so since about half ten this morning (when it did its usual and started quite badly, but not as much misfiring or smoke as usual), I've had the cam cover off to examine the state of the injector rocker rollers, cams etc, everything in view has a lovely clean sheen to it, plenty of oil (Castrol Edge by the way!) no scores or signs of broken crome plating, which was a relief. I've had the MAF sensor out (I know this usually makes it smoke under power and makes it gutless but just thought I'd rule it out), I've silicone sprayed the MAF connector, the water temp sensor connector, (which I believe has a direct effect on whether or not the glowplugs even come on) the fuel temperature sensor connector, and the connector on the 'little black box' that controls things like the flap valve on the EGR.

Now when I came to get to the water temp sensor down the side of the block, I realised that the connector was on back to front, so you couldnt unclip it, so I took out the securing clip and managed to turn it round without taking it out. In the attempt to access it, I took off the airbox lid to give more room, and the thin black hose which eventually feeds back to the 'little black box' more or less fell off! I dont know if this is of much concern as it only goes into the airbox, which is more or less atmospheric pressure anyway I'd guess unless your filter is badly blocked, and I suppose you wonder where all this is leading...........

It'd been sat there for about three hours, so more than enough time to go cold etc, and after rebuilding I gave it a start.

Result? Perfect start, just a wisp of blue/grey smoke and no misfiring!

So I gave it an hour to go completely cold again to check it wasnt a fluke, started again, wisp of blue grey smoke, no misfiring!

I can only conclude that after all this it had something to do with a connector, or possibly that one pipe! :wonder:

I'm going to keep an eye (and ear) out for crap starting and report back after a few days so its had a few chances to show itself again if its going to.............

Give as many connectors as you can find a squirt of silicone Mike, see if it works for you too!

Hi All, have you had the injection loom checked. it seem the right amount of miles for it to go.

i think they are about 50 quid to replace, but the tdi unit, doesnt matter if its a 1.4 or 1.9tdi, it makes the car shudder, but not really any difference in performance.

what happens is the wiring is in the cylinder head and oil gets on the wires, when you take the rocker cover off you will see what i mean, but this may be the problem. i had it on mine where it had rough idle and once i changed that iw was like new.

worth a try??

Could this difference in gradient be causing more oil to weep into the combustion chambers?

no deffo not..would have to be worn valve stem seals or piston ring problem.

Hi All, have you had the injection loom checked. it seem the right amount of miles for it to go.

i think they are about 50 quid to replace, but the tdi unit, doesnt matter if its a 1.4 or 1.9tdi, it makes the car shudder, but not really any difference in performance.

what happens is the wiring is in the cylinder head and oil gets on the wires, when you take the rocker cover off you will see what i mean, but this may be the problem. i had it on mine where it had rough idle and once i changed that iw was like new.

worth a try??

I did notice that when I had the cover off, I thought it was a wierd arrangment, having the wires somewhere they could get covered in red hot oil!

It has been much better lately, though how much this is affected by the really warm weather we've had recently I wouldnt like to guess.

I have however put a few tanks of top end fuel (V-Power/Ultimate etc) through it recently, plus had it remapped and it seems much better, even though I'm only using it on average once a week at the moment!

Once it gets cold again I may well look into the injector loom idea if it starts to struggle again, thanks for that.