Shuddering & Engine Light Displayed - Not a Coil Pack Issue - Opinions please.

[drgti]

Currently having issues with my 2006 Golf GTI DSG, originally experienced intermittent shuddering when accelerating (most noticeable uphill), during the shudder the engine light would flash.

Took the car to a mechanic, he took it for a test drive it didn’t occur & when the computer was scanned it didn’t show an issue or that a fault had occurred.

Drove it to work no issues, on the way home it happened again the worst I had experienced at this point & the engine light was now permanently displayed, returned it to the mechanic, he scanned it & it now showed the coil packs required replacement, he replaced them & I drove it home with no issues.

Next day it mildly occurred (once it starts it progressively gets worse) that afternoon it shuddered greatly (feels as if it is about to stall) & the engine light was permanently displayed once again, wasn't able to go over 10km without serious shuddering to occur, continued to get worse as I crawled home & it began to shake even at a standstill at the lights.

I called a tow truck & he arrived the next morning to drop it to the mechanic, the mechanic has pulled it off the truck, taken it for a test drive & the car is fine! No shuddering, no engine light, nothing..
He is a currently going over the car trying to find light on an issue but is yet to do so (it's been 2 x days),
I know the solution may be to just take it to a VW dealer but the original mechanic was happy to check it back over at no charge (due to the recent costs of an attempted repair) so thought i'd start there & check to see if anyone here has had a similar issue or any clue as to what this could be?

(I’ve read a few posts on similar instances yet majority have found the coil packs to be the issue yet mine have already been replaced & this has not solved the problem)

[Jmac]

It needs to be driven till its doing it, then the live data needs to be read. Misfire counter can then be checked, by the way it doesn't need to be an ign misfire to trigger the counter, injector, air leak , anything really that causes incorrect poor combustion. Unusual not to log a code or a pending code if its been illuminated for any extended period of time. Just rewinding a bit, you have new coil packs, there must have been a prompt for them to be replaced and my guess is it was a misfiore or he had pinpointed a certain cylinder?? Just piecing it up from your description. That's my take online, can be hard to diagnose but can easy to advise. Hope that makes sense and you guy can nail it.
Cheers
Jmac

[grtuned]

Shuddering & Engine Light Displayed - Not a Coil Pack Issue - Opinions please.

If the engine light came most probably an DTC was stored. Check your faults.

[vdubmotorworx]

sounds like he just saw a misfire and changed the coils instead of working it out...more than likely a injector going poop....if it logs cylinder 1 misfire then he should have swopped plug and coil to another cylinder...when the fault returned it would indicate if they were ok or not...if its still cylinder 1 then more than likely injector after a compression test....VDUB...

[Jmac]

sounds like he just saw a misfire and changed the coils instead of working it out...more than likely a injector going poop....if it logs cylinder 1 misfire then he should have swopped plug and coil to another cylinder...when the fault returned it would indicate if they were ok or not...if its still cylinder 1 then more than likely injector after a compression test....VDUB...

Yep, move it and watch the fault move, like I say it doesn't have to be an ign misfire to trigger a counter. Actually some ecus will switch off the injector when it logs a trigger with an air leak or the likes, that trips some up when diagnosing. Injector turned of by ECU. Its a good one that. Anyway hope it gets sorted.
cheers
Jmac

[Umai Naa!!]

Yeah, R36s do it, I've found.

I'm putting my money on an injector. You'll ideally need the install/removal tool kit to do the job. Probably worth buying new seal kits for the other 3 injectors, pulling them out, and cleaning all the carbon out.

[Jmac]

Yeah, R36s do it, I've found.

I'm putting my money on an injector. You'll ideally need the install/removal tool kit to do the job. Probably worth buying new seal kits for the other 3 injectors, pulling them out, and cleaning all the carbon out.

Yeah its cool hey. Many manufacturers do it. Yeah agree using the tool is way better as it is with most jobs. OP hasn't reposted so who knows
Cheers
Jmac

[drgti]

Cheers, appreciate the replies.

Update: Mechanic had said he was still unable to come across any issues whilst driving the car (it wouldn't play up for him) no faults were showing up on the scan up until yesterday when it was driven, no issues on the initial drive but once he returned to the shed & carried out another scan it has come back stating a fault with the air flow meter & that it requires replacement, which will happen today.

Re: injector, he said this is his next check.

[vdubmotorworx]

Airmass meter for a misfire issue....really.....i think not....

[Jmac]

If he had an Air mass fault be interesting to see what one, there is numerous Air mass faults and don't always relate to the unit itself. I don't think on a Mk5 ive ever had to change one they are pretty robust I find well thus far.
Interested to see what the final result is.
Jmac

[drgti]

I ran over the list of suggestions with him & he said all were definitely checked,
(he had it for 12 days total & assured me he thoroughly went over everything to find the possible causes for the fault)

He received the air flow meter from VW & replaced it approx 2 days ago, tested the car over the next 2 days & said there were no further issues/fault readings, I picked up the car yesterday & even though it's early days so far so good (also forgot to mention in my previous post the car would take 2 or so goes to start at any point during the day - this is also no longer an issue) I'm to monitor it over the next 2 weeks & report back to him, if there is any more issues within this time off to VW I go.

[drgti]

Double Post

[drgti]

Not much of an update seeing as nothing has changed, got the car back.. shuddering mildly occurred the day after.
Is still very intermittent, only driving it short distances so am only noticing the one shudder during the drive, spoke with the mechanic & got a run down on what has been done so far, in term of parts replaced they were:

- New coil packs x 4
- New plugs
- New fuel filter
- New airflow meter

Apparently it had showed up a different fault nearly each time it was scanned, these parts were the ones that were recorded (not including the fuel filter) hence why they were replaced, he said it may be beneficial to put it into VW as there is a small possibility that it has been throwing up incorrect fault codes & didn't want to continue to replace numerous parts if they weren't needed..