55 minutes ago, Warrior193 said:

What did the old plugs look like when you 'recently' changed them? (as you wrote last month)

Changed them approx 3 months ago, car was running fine then , didn't notice anything wrong them , they were just dye a change

1 hour ago, Warrior193 said:

That would definitely be an indication of something wrong with number 1 cylinder - if the 'oiling' on the plug is simply due to the plug not firing correctly, your engine will effectively be single cylinder in COD mode and would run very badly.

Runs ok except when it goes into eco mode

1 hour ago, Brian15 said:

Changed them approx 3 months ago, car was running fine then , didn't notice anything wrong them , they were just dye a change

If the original plugs were all approximately the same colour when they were changed 3 months ago, something has definitely changed since then. Does it definitely look like burnt oil on number one plug?

Not completely impossible for a new plug to be faulty.

Can you post a picture of the present plugs?

45 minutes ago, Warrior193 said:

If the original plugs were all approximately the same colour when they were changed 3 months ago, something has definitely changed since then. Does it definitely look like burnt oil on number one plug?

Not completely impossible for a new plug to be faulty.

Oil wasn't burnt , looked fresh

In which case, you need to have a compression test done, then find the reason for no spark on number one cylinder.

15 hours ago, Warrior193 said:

Can you post a picture of the present plugs?

Put them all back in now , they looked fine other than oil on plug 1

15 minutes ago, Brian15 said:

Put them all back in now , they looked fine other than oil on plug 1

Oil on the plug is not OK - it means either that plug isn't firing, or there is a significant problem with the cylinder.

Suggest a compression test on all the cylinders - especially on Cylinder 1.

It could also be a leaking valve stem seal. Think you need to do a leak down test to check but that may not pick up a bad stem seal as the valves are closed. From memory blue smoke only at start up from cold after sitting for a good while may point to a failed stem seal. Blue smoke while driving after warm up is usually worn piston rings.

Alasdair

1 hour ago, Alasdair1 said:

It could also be a leaking valve stem seal. Think you need to do a leak down test to check but that may not pick up a bad stem seal as the valves are closed. From memory blue smoke only at start up from cold after sitting for a good while may point to a failed stem seal. Blue smoke while driving after warm up is usually worn piston rings.

Alasdair

It's booked in with 'vw specislist' on wednesday

What kind of price range ish would you think I'd be looking at for either of the 2 possibilities you've mentioned ?

Sorry no idea what it would cost. I do all my own mechanics so a bit out of touch re costs but if its a valve stem seal then I assume labour charge will be more than parts. If its a bad piston ring then thats another ballgame. Probably cheaper sourcing a second hand low mileage engine as original would have to be removed and stripped down and rebuilt.

Had a broken valve spring years ago and my local goto garage managed to repair it without head removal. If its the stem seals then hopefully they have a special tool that can compress valves in situ and repair. In my casemy local mechanic friend fed soft string through spark plug hole then turned engine over by hand to carefully jam valves so he could compress spring and remove broken one.

Good luck and hopefully its something cheap and simple. It might be worth getting them to try and diagnose the problem first. Tell them if its going to cost a fortune to call you first before going ahead with repair.

Better to wait for compression test/diagnosis of fault, it could simply be one of the new plugs is duff - or a coil pack is failing.

Faulty piston rings would require a full engine rebuild, which could well be uneconomic.

Even a straightforward head rebuild could be more than £1500.

Engine management light came on today, plugged my cheap code reader in and got P040 which is linked to a faulty EGR, would a fault on EGR valve result in the car spluttering in 2 cylinder mode ?

If the egr is stuck open then it may be letting too much exhaust in and causing very lean mix which if the coil pack/plugs are poor could in theory cause a misfire/splutter. I would remove EGR and clean/check its actually working. P040 seems too short as so far I have come accross 4 digit fault codes and longer.

Alasdair

57 minutes ago, Alasdair1 said:

If the egr is stuck open then it may be letting too much exhaust in and causing very lean mix which if the coil pack/plugs are poor could in theory cause a misfire/splutter. I would remove EGR and clean/check its actually working. P040 seems too short as so far I have come accross 4 digit fault codes and longer.

Alasdair

I've missed the F off the end its P040F

Quick Google came up with :

Edited 13 November, 202513 Nov by Brian15
X

Just discovered 'topping off' never heard the term before but something I'm guilty of and no idea it could cause an issue.

Cars used for private hire so always filled it past the click without any idea it could cause issues

Might be worth getting it scanned with VCDS to see if it gives a more accurate reading of fault codes or pings anything else up. The purge valve on my sons mk1 fabia failed with similar fault codes. I replaced valve and seems to have cured problem. From memory I think it was around £20 off amazon and that was a Bosch one. On his its just two pipes and a connector so easy to swap.

His was on the left of engine looking from front of car.

Alasdair

Is that it ?

Yep I think so but cant quite read part number. Google part number on it and see what comes up. Check that there are no splits in the pipes first before replacing.

Alasdair

I’m getting oil on the threads of the spark plug in cylinder 2. I’ve always had a slight misfire in third gear and I’ve kinda just ignored it for about 70k miles. The car is used for private hire and is now on 155k. Excessive revving triggers a EML and limp mode but doesn’t come on under normal driving. Is this what you’re experiencing?

No have no oil showing on plugs. Sons car went into limp mode with EML on due to failed purge valve but he also had a vaccum leak at pipes to brake servo which was causing eratic idle etc. Its been fine since I taped up servo hoses and replaced purge valve. If there is oil on plugs then maybe a compression test/leak down test to check piston rings/stem seals are ok.

Did have a problem with my old 1.9tdi when it was revved high would go into limp mode and EML light on. It was overboosting due to sticking turbo actuator. I oiled it and manually operated it for ages till it moved smoothly. Have you had it checked for codes etc.

5 hours ago, Alasdair1 said:

Yep I think so but cant quite read part number. Google part number on it and see what comes up. Check that there are no splits in the pipes first before replacing.

Alasdair

Part number is 05E 906 517 A

But I can't for the life of me find the part anywhere

I cant find any either . Are you sure its 05E not 06E?

Alasdair

31 minutes ago, Alasdair1 said:

I cant find any either . Are you sure its 05E not 06E?

Alasdair

Don't think it matters, EML has just gone off !