Could be that the injector lash has not been set correctly or the cam lobe is excessively worn?

Hello everyone!   

 

A small update - I was unable to get to the VW specialist last week as owing to where it is, I'd have needed a lift home.  I love walking and 10 miles or below I probably would just walk but this would have been three hours to get home.  Anyway our friend couldn't do the lift last minute.

 

So I took it to a terribly-well reviewed new local garage (66 reviews, all 5/5 on Google) and they found that beyond around 30mph, the ECU is sensing an issue and shutting down injector 1.  This is when the shaking starts as it goes down to three cylinders.  Restarting cures this.   Either way though at all times it is slightly underpowered.

 

HILARIOUSLY (this is how I choose to see it!) they didn't check the wiring loom as they thought the previous garage had.  I said no they were going, they bought a new loom, and then just stopped.  He couldn't believe that.

 

So it could be...

 

1. Wiring loom (possibly damaged when the injector was replaced)

2. ECU/electrical/wiring fault elsewhere. 

3. He did say three out of four glowplugs had fault codes.  No problems starting, it is instant (no exaggeration) but can bad plugs cause issues even after starting?

 

Anyway it is going to the VW specialist in a few days now finally.

 

On 249,981 miles...I will make it!

2 hours ago, JamieH86 said:

Hello everyone!   

 

A small update - I was unable to get to the VW specialist last week as owing to where it is, I'd have needed a lift home.  I love walking and 10 miles or below I probably would just walk but this would have been three hours to get home.  Anyway our friend couldn't do the lift last minute.

 

So I took it to a terribly-well reviewed new local garage (66 reviews, all 5/5 on Google) and they found that beyond around 30mph, the ECU is sensing an issue and shutting down injector 1.  This is when the shaking starts as it goes down to three cylinders.  Restarting cures this.   Either way though at all times it is slightly underpowered.

 

HILARIOUSLY (this is how I choose to see it!) they didn't check the wiring loom as they thought the previous garage had.  I said no they were going, they bought a new loom, and then just stopped.  He couldn't believe that.

 

So it could be...

 

1. Wiring loom (possibly damaged when the injector was replaced)

2. ECU/electrical/wiring fault elsewhere. 

3. He did say three out of four glowplugs had fault codes.  No problems starting, it is instant (no exaggeration) but can bad plugs cause issues even after starting?

 

Anyway it is going to the VW specialist in a few days now finally.

 

On 249,981 miles...I will make it!

 

I'm a bit rusty re pd knowledge but the injector wiring loom is a known failure point as the wires sit in hot oil and eventually perish ,  and eventually fail especially if disturbed.

Easy , cheap fix though. 

Edited 1 February, 20251 yr by bigjohn

25 minutes ago, bigjohn said:

 

I'm a bit rusty re pd knowledge but the injector wiring loom is a known failure point as the wires sit in hot oil and eventually perish ,  and eventually fail especially if disturbed.

Easy , cheap fix though. 

Yeah hope so.   Two garages down and not checked yet... couldn't make it up!

 

Would a faulty wiring loom allow four-cylinder action (albeit at slightly reduced power) and then cause 1 injector to be shut down under a certain load?

11 minutes ago, JamieH86 said:

Yeah hope so.   Two garages down and not checked yet... couldn't make it up!

 

Would a faulty wiring loom allow four-cylinder action (albeit at slightly reduced power) and then cause 1 injector to be shut down under a certain load?

It might if the wiring is broken or a bad connection/insulation somewhere that loses continuity when heating up when under more current. 

8 hours ago, JamieH86 said:

Yeah hope so.   Two garages down and not checked yet... couldn't make it up!

 

Would a faulty wiring loom allow four-cylinder action (albeit at slightly reduced power) and then cause 1 injector to be shut down under a certain load?

 

Possibly - it can be a bit random. Heat and vibration changes things up...

 

It's a common issue with the pd especially re advancing age/miles and a relatively cheap simple fix - worth doing anyway.

 

 

 

Edited 1 February, 20251 yr by bigjohn

22 hours ago, bigjohn said:

 

Possibly - it can be a bit random. Heat and vibration changes things up...

 

It's a common issue with the pd especially re advancing age/miles and a relatively cheap simple fix - worth doing anyway.

 

 

 

Cheers.

 

To be honest the more I read (especially around fault codes relating to a specific injector being symptomatic of a wiring issue) the more it seems - or am I hoping? - that the wiring loom is at fault.

 

Especially as my symptoms can be traced back six months or so at a low level before going in December.   The new fuel injector smoothing the idle may be a red herring, as the loom will have been disrupted/moved.

 

Anyway will update after the specialist inspection.

Update - specialist diagnostic is no action from cylinder one.

 

The engine is three cylinders at all time, but a bit smoother with the new injector which made me think it was starting with four.

 

Electrical signals indicating a wiring issue were not found, so they are going to test by moving the injectors round etc to see if the issue follows injector one.

 

If so, good ... will replace it.

 

If not he said it might be more "terminal", something about rods and bottom ends.

 

Will update once the injector test is done!

Well... what an anti-climax.

 

The injector 1 was at fault, nothing more serious.  Switching it with 2 and cylinder 2 had the issue and so on.

 

But when putting them back in the right place, everything is fine.

 

The loss of power, the juddering... stopped.  

 

The range of the injectors is something like 1.0, -0.5, -0.6, 0.8 or something.  

 

They think the previous garage, he of "drive it better" fame, may just have bungled the installation of the new injector.

 

Now 'pulling like a train' I hear.  They want to test it from cold before releasing it.  If it does intermittently misfire in future though he said it'll be injector 1 not anything more serious.

For anyone interested!

Well... it's back now and running fine.

 

So the moral of the story is... don't use ****ty garages.

Glad to read that you're back on the road. 🙂

10 hours ago, Breezy_Pete said:

Glad to read that you're back on the road. 🙂

There is a sad ending though...

 

Noticed today it was on 250,007 miles.   Bloody missed it!

12 minutes ago, JamieH86 said:

There is a sad ending though...

 

Noticed today it was on 250,007 miles.   Bloody missed it!

 

7 Miles in reverse? Its not that far.

On 20/02/2025 at 20:08, JamieH86 said:

Well... what an anti-climax.

 

The injector 1 was at fault, nothing more serious.  Switching it with 2 and cylinder 2 had the issue and so on.

 

But when putting them back in the right place, everything is fine.

 

The loss of power, the juddering... stopped.  

 

The range of the injectors is something like 1.0, -0.5, -0.6, 0.8 or something.  

 

They think the previous garage, he of "drive it better" fame, may just have bungled the installation of the new injector.

 

Now 'pulling like a train' I hear.  They want to test it from cold before releasing it.  If it does intermittently misfire in future though he said it'll be injector 1 not anything more serious.

Well it did intermittently misfire again as that injector 1 was not the best (as the fact the fault followed it to cylinder 2 demonstrates).

However, here's an update...

I had a chap out this morning to fit the new injector who has worked on the car before and had quoted for the job in advance, but he found that the injectors were under the rocker cover and not outside.

He then advised I'd need a new gasket for this as it would no doubt be damaged on removal to fit the injector.

I was thinking, "I've just had an Audi specialist* in and out of this cover like nobody's business to run their tests and they never once worried about this".

I took it as a lack of confidence in the job, and certainly it dented mine in this mechanic, so I'll be going elsewhere, but has anyone ever heard of this concern before?!

*Said specialist are very good but a touch out of my price range for this job, especially as they insist on sourcing their own, brand-new injectors. C'est la vie.

Most mechanics on an unknown vehicle would want to fit a new gasket, they save nothing by not doing so and risk an oil leak, an unhappy customer and having to do the job a second time for free.

The exception would be if they had recently removed and replaced the cover with a new gasket and not used sealant.

I was helping a friend today whose 2.0 DCi transits timing gears and wet belts had lunched themselves, we pulled the cam ladder frame assembly off to see if the valves were bent, he asked me if he should replace the gasket, I said no as it was thick plastic and had seperated without damage, had he asked me before we stripped the engine I would have said yes, he will probably buy one with the other parts anyway.

VAG would insist on the gasket being replaced every time.

15 minutes ago, J.R. said:

Most mechanics on an unknown vehicle would want to fit a new gasket, they save nothing by not doing so and risk an oil leak, an unhappy customer and having to do the job a second time for free.

The exception would be if they had recently removed and replaced the cover with a new gasket and not used sealant.

I was helping a friend today whose 2.0 DCi transits timing gears and wet belts had lunched themselves, we pulled the cam ladder frame assembly off to see if the valves were bent, he asked me if he should replace the gasket, I said no as it was thick plastic and had seperated without damage, had he asked me before we stripped the engine I would have said yes, he will probably buy one with the other parts anyway.

VAG would insist on the gasket being replaced every time.

Cheers! Fair enough then. Well they're £20 so hardly a deal breaker.

If somebody quotes to replace an injector on a PD engine and they are surprised that the injector is inside the rocker cover......

FOR THE LOVE OF GOD RUN FAR AWAY FROM THIS MAN

Edited 10 March, 20251 yr by SuperbTWM

13 hours ago, SuperbTWM said:

If somebody quotes to replace an injector on a PD engine and they are surprised that the injector is inside the rocker cover......

FOR THE LOVE OF GOD RUN FAR AWAY FROM THIS MAN

That was my concern but I didn't know if I was being harsh.

Not harsh at all. Its your car and your money. How someone can give a fixed quote without looking/checking or knowing the engine would worry me in the first place. Once got a quote to replace timing belt on a Toyota lucida people carrier. Seemed very fair price until the garage realised that it involved removing front seats and floor pan plus front Aux shaft just to get to timing cover. They had no clue the work that was involved. When I took it in they made up some excuse and said they couldn't do it after all as they thought it was the petrol version even when I had told them it was a 2.2 3cte turbo diesel. Probably just as well they didn't get the job.

My local garage(retired now) used to always inspect cars before giving a price unless they had worked on the car before.

Alasdair

1 hour ago, Alasdair1 said:

Not harsh at all. Its your car and your money. How someone can give a fixed quote without looking/checking or knowing the engine would worry me in the first place. Once got a quote to replace timing belt on a Toyota lucida people carrier. Seemed very fair price until the garage realised that it involved removing front seats and floor pan plus front Aux shaft just to get to timing cover. They had no clue the work that was involved. When I took it in they made up some excuse and said they couldn't do it after all as they thought it was the petrol version even when I had told them it was a 2.2 3cte turbo diesel. Probably just as well they didn't get the job.

My local garage(retired now) used to always inspect cars before giving a price unless they had worked on the car before.

Alasdair

Yeah that's fair enough. Well it's booked in at a reputable garage now for the job and I found a new gasket for £9 anyway.

Well... All done!

New injector (reconditioned Bosch, not an eBay job), new rocker gasket, 3 x new glow plugs (plug 2 stuck) oh and a new coolant resevoir, as mine developed a split. £275 in all for parts and labour.

Despite the testing in February being done at a reputable VW specialist, this week's garage said the specialist had not tightened all the rocker cover bolts and had also not replaced a single-use bolt that keeps the injectors in place (if that sounds right).

Anyway I have forgotten what "normal" in this car is now. Runs fine, starts fine (what I might call a "throb" feeling on the first kick of the engine then normal) I think I'm dulled to the whole saga now though!

A Long run this weekend as a treat for it.

23 hours ago, JamieH86 said:

Despite the testing in February being done at a reputable VW specialist, this week's garage said the specialist had not tightened all the rocker cover bolts and had also not replaced a single-use bolt that keeps the injectors in place (if that sounds right).

This is a common occurance, even at the main dealers and when one inevitably snaps off in the head and needs drilling out it is the customer that pays the price!

Well well well... it was with a sense of wearing expectation that I saw the engine management light come on on Sunday.

However rather than another injector going or the new one failing, it was the wiring of the fuel temperature sensor that had broken (and new sensor added anyway).

This must have been playing up for a bit anyway, perhaps intermittently working, as the "throb" I mentioned last week and the general feeling things were around 97% sorted but not quite 100% (if you know your car, you know) has gone and it really is now back to ... well, not new, but pretty good for its age.

ALL FINGERS CROSSED that's it now.

Edited 9 April, 20251 yr by JamieH86