JamieH86

There is a sad ending though... Noticed today it was on 250,007 miles. Bloody missed it!

Well... it's back now and running fine. So the moral of the story is... don't use ****ty garages.

For anyone interested!

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.

I had something similar. The bulb warning kept coming on even after checking all bulbs and replacing one, it was just a loose wire/connexion in the end.

If you hadn't said that, I would have! Our boot did this once; you could hear the motor going when you pressed the button and if you looked through the window you could see the "nudge" (whatever it's called) move a bit but not enough to release. Much lubrication later and it was perfect. These things just get stiff. As for the car... ahahahaha. Etc.

Sounds normal to me for when you approach the end of the runway!

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!

Is buying off eBay for that price a thing? Seems very risky.

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.

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?

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!

Mine has had two new starters in 250k miles. Former taxi. One at around 120 and another at 170.

I think it is yes, especially now - an update! Despite telling me on Monday they thought it was the wiring loom and they were going to replace this, and a new loom was even ordered, I found today on picking the car up that they did bloody nothing with it. It was still in plastic in the box as he "didn't think it was the wiring after all" and told me again to just take the car out and rag it round. Well I am down overall only £80, as that is what he charged to change the injector, so I can call it a day at that garage with fair confidence. Driving home the idle at stationary is still very smooth, and driving up to 20mph (lucky I live in Wales!) there was no juddering at all. It was noticeable on inclines though that it lacks its usual power. Getting to 30mph, the shaking starts. Restarting the engine stops this until you get to 30mph again. So it could be a wiring issue, as that turns out to be uninvestigated, or a dodgy second hand injector. Either way I should know on Tuesday. In the meantime I will not be going up and down the M4 to see if the injector fixes itself.

To be fair I am happy to take your word - as you are not offering advice like "drive your malfunctioning car to health"! I am not going to order an injector yet or have any more work done at this garage. I've got it booked at a VW/Skoda specialist down the road in Newport now to fully investigate the whole wiring, injector and fuel system and take it out and see what is happening, for £80.

Cheers, I agree 2 sounds somewhat optimistic. It is slightly starting to get the beginning of irritating now, this issue. I'll put a brief history here to recap this whole issue (which has been across a few different threads, in different stages/symptoms):- April 2024 - slight hesitancy on hill starts, had to push the gas. Gust of black smoke on last such occasion then this never happened again (still hasn't reoccurred). May 2024 - started vibrating and being underpowered randomly after entering a sliproad to the M4 and speeding up. Pulled over, restarted engine, issue went away. June 2024 - no issues. July 2024 - started vibrating and being underpowered randomly again after leaving a roundabout and speeding up. Pulled over, restarted engine, issue went away. Did have fuel injectors cleaned. August 2024 - no issues. September 2024 - no issues. October 2024 - no issues. November 2024 - no issues. December 2024 - issues. Failed MOT on emissions. Had two courses of Forte diesel system cleaner, Italian tune-up and the EGR valve cleaned, but still failed. Did then pass at a different garage on a higher test limit but result still higher than last few years (1.2-). Had a few occasions where it would tremble or hesitate on a drive, often in fifth, then this would clear again. Had it for one week post MOT then the fuel injector 1 seemed to go (according to scan). Very rough idle, engine bucking, underpowered much beyond 10mph. Laid up during Christmas. January 2025 - had fuel injector replaced and according to the garage, coded (I've searched a lot to see if this is necessary and it *seems* like it should be, and another mechanic, who did the service and first found the injector issue, said it would need it as well). This sorted the rough idle but the car was still slightly underpowered and beyond 30mph or so just trembling/shaking again. Bit more power though, it could slowly get up to a higher speed but felt wrong to drive. Wiring loom checked and ok. Options now - keep at mechanic, get a new injector to try. Question over accuracy/quality of job? - take it elsewhere, see what someone else says, but starting from scratch and potentially a lot more costly. - drive it around and hope it gets better. Well, I'll cross that one off! Feeling a bit stuck now, though also not totally despondent - perhaps I did just get unlucky with a crap injector second hand and a new/reconditioned one will sort it. Any other insight based on the long history above, do let me know your thoughts!

Hi all, well good news the injector was coded. However the new error code is still for number 1 injector (the wiring loom has been checked and was fine). The mechanic thinks either: 1 - second hand injector was just no good. It was working differently to the old one, hence slightly different symptoms, but just as badly in its own way. 2 - the new injector is fine and the car just needs driving with a fuel injector cleaner additive. I know the additives can take a few miles to work but I am reluctant to drive the car round when it is not functioning properly in case this causes damage - would others agree? To me the best option seems to be bite the bullet and buy a new injector (and sure there's a lesson there about doing a job properly once, but Christmas and all that etc etc!).

I mean... on the one hand, a non-coded injector could deliver what I'm seeing. On the other... it didn't even occur to me to ask if he'd done it, it's basic. If the scan code is for the same injector tomorrow I might "casually" enquire. "Maybe it needs to be coded again?" Heavy emphasis on "again"!

Yeah that did go through my mind but I'd have thought in my case the trembling would continue at 50mph, say, regardless of being in gear or neutral. Will see what the engine light indicates when I hear from the mechanic. Alas they all seem to rely on codes and scans, though this bloke is fairly old school, but whilst I would replace a boot switch or air filter I am simply not a mechanic at all and I think a DIY engine exploration after watching five minutes of YouTube is not something I want to do!

Hello again, update - new injector is in and I have to say, the idle is now very smooth. Noticeably smooth. No complaints there. If the purpose of a car was to turn on the ignition then leave it running to admire how smoothly it can idle, job done. However, driving it away from the garage (which involves a small incline to the junction), it was immediately obvious to me it was not as powerful as it should be. Drove ok though, until I got to about 30 mph when the trembling/shaking started again. This was only on acceleration; if I put the clutch down it was smooth as the Atlantic was when Titanic sank. Stopped and started again, and it was ok in low speeds again but around 50 this time the trembling, shaking came back. Once it was back, it also applied to low speeds - I couldn't drop down to 20 say to smooth it out. Once it started, it stayed. The engine light then came on again, so back to the garage. Will update of course.

Hello all! Christmas being Christmas there was a) a massive delay in getting work done and b) I was somewhat financially fanciful in getting everything done! Still injector 1 has been replaced... I have not yet picked the car up but as per the mechanic: he says the bucking, rough idle has gone and the car can drive and accelerate as usual (it struggled much above 10mph before). However he thinks there might be the odd misfire possibly still. No engine lights, and he says it might just be the new injector "settling in" and possibly a fuel injector treatment would help.

Mine started doing that, then the motor eventually died (and the cheap blade fell off!). That was five years ago now, I must replace it some day!

Cheers. Good point about the glow plugs, I suspect they're original too. I had a nippy petrol Fiesta many years ago that fired on three cylinders once owing to a spark plug failure so... I am not 100% of the relevance of that but yes, glow plugs sounds sensible.

Looking through the pretty comprehensive history, I can't see the injectors have ever been replaced so assume they're original, and have done 250k miles. Can't really complain.

Yeah I am not buying anything this side of Christmas until it's been double-checked!