Hello helpful Octavia folk! My 2017 plate 1.4 TSI DSG (97k miles, regular servicing at trusted independent garage) has been diagnosed with a faulty Crankcase Ventilation Valve by a company called “Scantec” in Hailsham, Sussex.

It’s had an issue that’s been coming and going for a while now where once it was warmed up and usually after long drives it would have auto stop/start error followed by flashing EML when stopped, but would go away when moving off, and didn’t feel much like a loss of power or heavy fuel use (still getting 50+ mpg). Multiple engine misfire codes detected, concentrated on cylinder no.3. Spark and coil packs were replaced a few months ago and seemed fine but the problem had returned, and my local garage sent it to Scantec where they’ve diagnosed this PCV fault.

Yesterday was a bit sad because the usual car part suppliers don’t sell these valves as standalones, and VW group said that the whole of the top of the engine would need replacing, so I was quoted nearly £2,000 after labour by my local garage. For a car that’s worth about £6-7k I can’t really justify that expense, gutted though as I think it’s still got loads of life.

This morning however I have come across these parts on eBay! If it is just the PCV valve that’s faulty, please could you kindly tell me if these are the correct parts (not sure what the difference is between the cylindrical valve and the the longer hose section?) if so that‘ll be an enormous relief - £30-40 plus a bit of labour is a bit more positive than £2k!

https://www.ebay.co.uk/sch/i.html?_nkw=crnkcase+ventilation+valve+skoda+octavia+2017+1.4+tsi+mk+iii

Thank you kindly in advance for your expertise!

Kind regards

Ed

Edited 18 December, 202518 Dec by EdHilton

I suggest that you go look at somewhere like Autodoc for the separate PCV valve. They do exist still; it's just Škoda being tight.

Thanks varaderoguy. Do you know if those parts on eBay are what the valve is supposed to look like? I’m not sure what I’m looking for to be honest. The diagnostic company advise against stripping the camshaft down to replace the valve but there must be a cheaper way!

Can you get us the original part number for the existing PCV valve please on the engine?

Have had a conversation with a technician at Skoda who said the part number for that engine block breather valve is 04E103175.

However he thinks the PCV valve actually sits on the side of the crankcase and which degrading of the valve is a common issue. These seem to also be called oil trap / crankcase breathers…

https://www.autodoc.co.uk/bogap/18571281

The part numbers he quoted for those were 04E103464AM for the breather/oil separator and 04E103729 for the cover.

@EdHilton how did you get on with this in the end? What part or parts (e.g. is the cover required) did you need to successfully replace your PCV valve?

Hi @netman82 thanks for your interest. Incidentally I’ve just got back from my local garage for a scan and happy to report it’s all fixed! The parts required were the crankcase breather/oil separator and its cover (04E103464AM & 04E103729, pictures attached). Got them both from Skoda direct for about £70 in total. The other part I listed that was on autodoc (https://www.autodoc.co.uk/bogap/18571281) turned out to not be for my car.

As a complete non-mechanic I’m struggling to understand how two new bits of plastic have fixed the issues as the garage said there was no visible signs of damage on the old parts, but hey ho!

Kind regards

Ed

I'm with you @EdHilton , I'm completely clueless when it comes to such mystical mechanical shenanigans, much to my embarrassment, so I'm very grateful for all the contributors on here helping the likes of us out, and that's you included now, thank you :) I have the part numbers I need now! May I ask how much the work cost to carry out please? The part seems to be in a tricky location.

You’re welcome! Are you also getting multiple misfires with no real sign of deceased performance or fuel consumption?

My local garage fitted it in a little over an hour I think. Apparently it’s at the front end tucked under the radiator (near the water pump?) so they lifted the car but said it wasn’t too bad to access. I’ve included a diagram sent by a very helpful Skoda mechanic - the second picture highlights those parts in red. Cost was about £150 for the labour (sadly everything leading up to finding the cause of the multiple misfires was £480!! including a trip to a specialist VAG who diagnosed it, but initially said the whole camshaft would need replacing!)

Make sure they clear any fault codes. Then I took it in a couple of long drives to allow everything to warm up (the misfires seemed to happen when everything was hot). Took it back to garage to plug in again to make sure no more codes came up.

Hope that helps! Good luck

1066_001.pdf

I'm surprised they did not change the pvc valve too on top of the valve cover as the parts you mentioned is just an oil separator, that filters oil from the fumes so the oil drains back into the engine.

@wiilydog is that the breather valve (as mentioned further up the chain) you're referring to?

Hi @wiilydog , yeh that was actually changed before the separator as it was a cheaper part than the others, and also seemed to also be positioned slightly out of alignment in its housing. However after a long run the misfire codes were still cropping up…

2 hours ago, EdHilton said:

Hi @wiilydog , yeh that was actually changed before the separator as it was a cheaper part than the others, and also seemed to also be positioned slightly out of alignment in its housing. However after a long run the misfire codes were still cropping up…

Yes was referring to breather valve. Glad it is all sorted now as sounds like the old parts were gummed up.

On 03/02/2026 at 21:40, EdHilton said:

You’re welcome! Are you also getting multiple misfires with no real sign of deceased performance or fuel consumption?

My local garage fitted it in a little over an hour I think. Apparently it’s at the front end tucked under the radiator (near the water pump?) so they lifted the car but said it wasn’t too bad to access. I’ve included a diagram sent by a very helpful Skoda mechanic - the second picture highlights those parts in red. Cost was about £150 for the labour (sadly everything leading up to finding the cause of the multiple misfires was £480!! including a trip to a specialist VAG who diagnosed it, but initially said the whole camshaft would need replacing!)

Make sure they clear any fault codes. Then I took it in a couple of long drives to allow everything to warm up (the misfires seemed to happen when everything was hot). Took it back to garage to plug in again to make sure no more codes came up.

Hope that helps! Good luck

1066_001.pdf

Thanks Ed; apologies for the delay. No such issues for me as yet, but this topic (PCV valve replacement) has been talked about elsewhere as preventative measure on cars of a certain age, so my interest was piqued when I realised you had the same engine (not all PCV valves are made equal, it would seem!). Thank you for the diagram, I was sent a similar one from my local Skoda parts department when making enquires. And also for the additional information and details. I do wonder whether I should bother with the preventative maintenance right now, given the cost could be £200+ all-in. Good work on getting it all sorted in the end, in spite of the cost. It sounds like the saga I had with trying to get my steering wheel straight (a long story about how these wheel alignment machines don't have the correct specs for my particular vehicle, but insist that they do!).

Here is a DIY guide for the oil separator replacement

Volkswagen Golf Service & Repair Manual - Removing and installing oil separator - Crankcase breather