Engine judder when idle?

[TeamKHK]

Evening all,

I've had my GT TDI (BKD) for a couple of months now and even though all is well, I've noticed that when the engine is idling away there is a 1 second but minor judder. It happens when the engine is both hot or cold, but more noticeable when hot and will occur every 10 seconds or so.

It's been pondering me for sometime and something else I've noticed too is that the engine itself appears to start way too fast, I don't think I've ever heard it crank over - literally a flick of the key after glow plug light out and it fires into life hot or cold... However as soon as it fires up, a very noticeable engine jolt / shake occurs which can be felt throughout the car - and it's noticeable from the look of the engine with the bonnet open too.

After some heavy research and after finally digging out my old ELM327 lead - I managed to hook it up to the laptop & VCDS lite. Thankfully no codes are present what so ever but taking a look at the live measurements and in particular block 4 - I see the idle stabilization is displaying -2.9 CF (torsion value / KW if viewed on VCDS non lite), which means it's slightly out from what I've discovered (should be dead on 0 apparently?). Block 15 - fuel consumption is bang on at 0.60 l/h.

Now I reckon my two minor niggles are linked, but have any other diesel owners out there experienced this before or came across this?

Many thanks - Liam.

[ZigzGTI]

had the same issue on my Leon TDI- it was the mass air flow sensor fuse (luckily just the fuse) and also a build up on soot (i usually did local city drives)

[TeamKHK]

had the same issue on my Leon TDI- it was the mass air flow sensor fuse (luckily just the fuse) and also a build up on soot (i usually did local city drives)

Thanks for the heads up. Did the car throw up any error codes in your case? As on mine - nothing at all, not even anything previously stored. However I will look into this as well.

I've got a torque wrench on the way as I'm going to tackle the front cam adjustment myself and see how I get on.

Liam.

[Christiank]

I've had the same issue with mine 140PD BKD engine.
Tried all sorts of stuff without any help - and came to the conclusion that I just had to rebuild a lower milage 2.0tdi pd140 from 2008 with the revision "C" head.

My current engine started with symptoms like yours but just got worse and worse. Now I've got an error on cylinder 4, and I can see by vcds measurements that the injector on cylinder 2 also has some problems.

Talked to a 2.0tdi 140pd guru and he says that the cylinder or nozzle heads slams so hard down in the blok that it eats the metal which eventually will make the injectors not function problerly.. He says it can be fixed if you injector hasn't suffered any damage by putting new injector seals and some oversized O-rings.

But this is just on problem amongs many others that will shop up when these engines lay down some milage every year :)
Mine has driven 365.000KM so far without any big problems.. Well until now 

My engine to rebuild should hopefully show up last next week :D

[ZigzGTI]

For some reason it would trigger off a fault code for glow plugs which i changed but then mechanic had me change things from the cheapest upwards and luckily the £2 fuse did the job. im guessing the MAF sensor has some correlation with the glow plugs.

had the same issue on my Leon TDI- it was the mass air flow sensor fuse (luckily just the fuse) and also a build up on soot (i usually did local city drives)

Thanks for the heads up. Did the car throw up any error codes in your case? As on mine - nothing at all, not even anything previously stored. However I will look into this as well.

I've got a torque wrench on the way as I'm going to tackle the front cam adjustment myself and see how I get on.

Liam.

[TeamKHK]

For some reason it would trigger off a fault code for glow plugs which i changed but then mechanic had me change things from the cheapest upwards and luckily the £2 fuse did the job. im guessing the MAF sensor has some correlation with the glow plugs.

had the same issue on my Leon TDI- it was the mass air flow sensor fuse (luckily just the fuse) and also a build up on soot (i usually did local city drives)

Thanks for the heads up. Did the car throw up any error codes in your case? As on mine - nothing at all, not even anything previously stored. However I will look into this as well.

I've got a torque wrench on the way as I'm going to tackle the front cam adjustment myself and see how I get on.

Liam.

Yeah I've heard of that before with the glow plug fault code. Well I think my MAF readings look normal according to VCDS and the car still pulls through the revs & boosts fine so I'm ironing that out for now.

Liam.

[jason_rmh]

I have the same issue, for a few year. It's not really got any worse I don't think.
I adjusted the torsion value and it made no difference to the judder.

In vcds I can see one of the injectors is noticeably different from the others when I do a logging graph.

My next step was to get the injectors tested / refurbished as they're probably due anyway due to mileage increasing.

If it's not injectors, could be worn cam lobes (from what I've read).

However, the car does run fine so it's never been an issue, I'm now on 180,000 (got the car at 80,000).

I change oil and filters, including fuel filter every 12,000 miles and always run a can of neat diesel purge before hand.

Despite this, the judder prevails, making me think it may not be totally down to injectors.

Jas

[TeamKHK]

I have the same issue, for a few year. It's not really got any worse I don't think.
I adjusted the torsion value and it made no difference to the judder.

In vcds I can see one of the injectors is noticeably different from the others when I do a logging graph.

My next step was to get the injectors tested / refurbished.

If it's not injectors, could be worn cam lobes (from what I've read).

However, the car does run fine so it's never been an issue, I'm now on 180,000 (got the car at 80,000).

Jas

Thanks for your input mate.

Yeah I've read elsewhere online that others who have also adjusted the torsion value have not been successful, some are but I'll see with mine in s couple of days when I do it.

What are your injector readings by any chance? I'm not too familiar with what is considered normal but two of mine are around the 0.20 mark and the other two sit at around -0.40, it all depends on how warm the engine is but that's how mine are when up to temp.

Saying that and like you say, overall running and performance isn't hindered - oh and nice mileage too, hopefully mine lasts for that long  (currently on 109K).

Liam.

[jason_rmh]

I think you should always get the engine upto temperature before taking accurate readings.

I'll check my injector readings again and post back for comparison.

Jas

[TeamKHK]

I think you should always get the engine upto temperature before taking accurate readings.

I'll check my injector readings again and post back for comparison.

Jas

Sorry yeah I was meant to say that injector readings can seem higher if the engine isn't up to temp, the ones I posted above were after a good 20 mile run. Ok nice one.

Liam.

[TeamKHK]

Finally managed to give the torsion value adjustment a go earlier on today. Marked up the cam with the centre bolt & the first attempt proved that I must of gone too far advanced (despite literally only moving the bolt 3mm or so clockwise), engine fired right up but sounded lumpy when revved to 1500rpm and VCDS reported that the torsion value was exactly 0.0 CF / KW - which is also the common sign that the torsion value is way too out.

Second attempt, notched the centre bolt counter clockwise by about 2mm and tried again - engine sounded better this time but the value was now showing still advanced but this time at 2.5 CF/KW.

Third and final attempt for today and had to stop here due to being out of time at work - notched it back counter clockwise again and it very nearly lined up with the original line that I marked on the cam (I actually thought that I went far too back). However upon firing up the engine again I noticed instantly that it sounded and felt better than ever before, and VCDS now reports it as -1.0 CF / KW but does occasionally flick to -1.5 CF/ KW when at peak temperature.

I noticed when driving home that the car feels a bit more smooth when setting off, going through the revs, changing gear & when making use of the turbo's full potential and also noticed how quieter it is when idle too. The occasional judder is still there when idling away but it's barely noticeable and probably will improve more if I get the chance to make further adjustments to get it bang on 0.5 CF / KW tomorrow. It really is madness to see how much of a difference a slight notch can make to the overall running of it.

Liam.

[jason_rmh]

Its been a while but I was replacing my cambelt at the weekend and had to revisit the torsion value.
So, for the past couple of years, my tdi has had a lumpy idle, although it seems intermittent. More noticeable after a long run and then coming to a stop at traffic lights.

I had already attempted to adjust my torsion value and it didnt make much difference.
I got my torsion value to 0.5 before I gave up.

After replacing the cambelt, tensioners, rollers etc warming up the engine, my torsion value was at 2.9, lumpy idle still present.
I Adjusted the torsion value by adjusting the front (inlet) cam sprocket and go it to bang on 0, however, the lumpy idle was still there.

I then turned my attention to the fuel consumption (block 15). At idle, this was fluttering between 0.4l/h and 06.l/h. It should be 0.6.
So I adjusted the fuel consumption by making adjustment to the rear (exhaust) cam sprocket.
I got it to 0, and the lumpy idle has disappeared.

It may be in my head, but the car feels a little smoother to drive and certain not juddring when sat at traffic lights!

So, in summary:
You need to check BOTH blocks 004 and 015 (once the engine is up to temperature):

• Torsion value (measuring block 004) is at 0.0 KW
• Fuel consumption value (measuring block 015) is at 0.60 l/h

Hope this helps someone.

Jas
 

[abz132]

I was having the same issue. I was feeling a rough judder on idle which was even shaking the seats. Replaced the clutch and flywheel and it sorted the issue.