Hey all,

 

The car concerned is a 1.4 TSI with the caxa lump. It has recently (within last year) had new timing chain, new coilpacks, new spark plugs, throttle body/valve cleaned and a couple of oil changes. Since the timing chain and associated gubbins were replaced, it's started like a trooper and unless it's doing the irritatingly noisy I'm at X temp heat/crossover timing thing, is very very quiet when running.  I haven't really driven the car much as it isn't mine, but after using it a couple of times I became aware of a lumpy idle which prompted me to take it to a friends some distance away for a dose of VCDS. You can hear the engine not firing correctly at idle at the tail end of the car where there is a slight hiccup every so often. 

 

VCDS picked up P0300 ( Random / Multiple Cylinder Misfire) and also had P0304 which I believe relates to Cylinder 4 experiencing a/multiple misfire(s).  Whilst I only have Carista and Torque available to myself here, I did log the fuel rail post engine shutdown from just above idle rpm, which I hoped would rule out any injector being stuck / leaking but the results suggest otherwise. I'm not sure where this graph will attach but please see image showing pressure drop.  The car in the morning will report what I believe to be low pressure pump pressure which is around 7 Bar. This increases to 50Bar at idle and somewhere up near three figures with WOT. My question to you guys though is this - would you lean towards changing the fuel injector on Cylinder 4 based on the misfires and the rail pressure drop? This rail drop doesn't happen all the time, but when it starts to up the misfire counter for cylinder 4 (which sometimes goes up at the rate of 1 a second) you can hear it at the tail end of the car. Shutting the car down when it's doing this also results in you being able to see the fuel rail pressure dropping, rather than increasing with heat soak as expected (at least, according to a video I watched on youtube created by VCDS).

 

If anyone has any ideas I'd really appreciate your thoughts - I'm happy to replace the injector... I guess with a new rather than used one as it at least comes with the seals and some sort of guarantee then? I had considered a carbon clean for the valves also, but the local guys weren't keen as they believe that you can't remove the intake runner plate (sorry no idea on correct term) things making it more difficult. They quoted £500 for the work, if they were able to gain access. 

 

Thanks all.

 

PS - Where's the best place to get VCDS in the UK? (Genuine please only). I think it's time I invested in my own. 

 

 

I recently did a carbon clean and injector replacement on mine and completely understand the price tag! (It was a ccza, but fairly similar in amount of work required I think).

 

It's quite involved and takes a fair amount of time as well as needing the right tools.

 

If you don't have the right tools/bits then you're going to struggle.

On 02/11/2021 at 09:55, bspman said:

I recently did a carbon clean and injector replacement on mine and completely understand the price tag! (It was a ccza, but fairly similar in amount of work required I think).

 

It's quite involved and takes a fair amount of time as well as needing the right tools.

 

If you don't have the right tools/bits then you're going to struggle.

The inlet manifold is on the backside of this engine so the job probably comes with free tractor back......  Finding a genuine injector (read not necessarily vag stamped - but a magnetti marelli unit isn't easy!).  Injector price from dealer is £250 odd, the magnetti marelli is £150 and I believe is the OEM unit. If anyone can advise whether any other suffix units can be fitted I'd appreciate it. Currently going on 03c 906 036 F, though I see some parts sites that suggest the M and F suffix to fit the same cars.

On 08/11/2021 at 00:22, -mike- said:

The inlet manifold is on the backside of this engine so the job probably comes with free tractor back......  Finding a genuine injector (read not necessarily vag stamped - but a magnetti marelli unit isn't easy!).  Injector price from dealer is £250 odd, the magnetti marelli is £150 and I believe is the OEM unit. If anyone can advise whether any other suffix units can be fitted I'd appreciate it. Currently going on 03c 906 036 F, though I see some parts sites that suggest the M and F suffix to fit the same cars.

Have you checked to see if opie oils has any injectors?

 

Edit: VCDS probably from gendan or ilexa. 

Edited 10 November, 20214 yr by bspman

On 10/11/2021 at 10:53, bspman said:

Have you checked to see if opie oils has any injectors?

 

Edit: VCDS probably from gendan or ilexa. 

I did give them a call and they don’t have injectors at all for it. The idle is getting progressively worse now so whatever the issue it needs to be found!  The fuel economy is absolutely terrible at this point too 😔

Out of curiosity what do the spark plugs look like now with E10?

I had rough idle on 280 and it was camshaft magnet.

Also had misfires on idle, but without faults, just saw them in vcds.

Check with vcds if you have camshaft adjustment intake and/or exhaust, actual and specified values. They should be pretty much the same.

 

Is it happening when engine is cold or when it warms up a little bit?

Edited 16 November, 20214 yr by Bingodalton

1 hour ago, MicMac said:

Out of curiosity what do the spark plugs look like now with E10?

it gets fed super unleaded so I can’t answer that question unfortunately! They were sooty when I changed them though! 

1 hour ago, Bingodalton said:

I had rough idle on 280 and it was camshaft magnet.

Also had misfires on idle, but without faults, just saw them in vcds.

Check with vcds if you have camshaft adjustment intake and/or exhaust, actual and specified values. They should be pretty much the same.

 

Is it happening when engine is cold or when it warms up a little bit?

It has camshaft measurement for intake iirc, I think specified at idle was 19.5 and actual was between 18.5 and 19.5 . Not sure how far these can be out? It from my limited time driving it does it more when it’s warm. Cold it sounds like a diesel while it does it’s car warmup then quietens down. 

re plugs

 

Maybe worth a look/clean.

7 hours ago, -mike- said:

it gets fed super unleaded so I can’t answer that question unfortunately! They were sooty when I changed them though! 

It has camshaft measurement for intake iirc, I think specified at idle was 19.5 and actual was between 18.5 and 19.5 . Not sure how far these can be out? It from my limited time driving it does it more when it’s warm. Cold it sounds like a diesel while it does it’s car warmup then quietens down. 

Then this is ok, +/- 1 sound good. Mine was fluctuating +/- 13 without dtc.

As other asked, when did you replaced your spark plugs.

First thing to do is regular service, oild, filter, spark plugs if it is not done recently.

You can change the places of coild plugs. So, move from 4 cylinder to some other, for example 2. See if misfire moves to 2. Cylinder.

For fuel pressure, you jave actual and specified, follow this on idle if they are the same within some percentage margin and look if it sudenly drops when it misfires.

You can check Short term and Long term fuel trims and see if Long has gone up or down. 

You can check misfire counter for all cylinders, maybe just 4 is having more misfires, and all other have misfires too, but as it is random, then it is common problem for all 4.

Vacuum leak, fuel pump, spark plugs, very dirty air filter,...

Thank you both for the replies above, I’ll report back on these at the weekend when I have enough daylight to see! 
 

does anyone have a part number for the o-ring that the vvt /n205 solenoid uses? The dealership I rang couldn’t see it as a separate part 😞

Pop into your local German supermarket or cheap DIY outlet, you can buy a big box of assorted o-rings for less than a fiver, or nip to an indie garage for one from their box for pennies.

Edited 18 November, 20214 yr by MicMac

I did not see it either. There is rubber seal around it as separate part, but not O-ring.
Maybe it is 21, but position of O-ring looks strange on the picture.

At least you can see dimension and try to find it. 

6 hours ago, MicMac said:

Pop into your local German supermarket or cheap DIY outlet, you can buy a big box of assorted o-rings for less than a fiver, or nip to an indie garage for one from their box for pennies.

Thank you for taking the time to reply. Will any o ring be ok? Not sure how hot this area gets but assume oil temperature? I have fitted one from a box of Lidl specials after cleaning the valve. I worked the valve many times whilst spraying with cleaner - then submerged only the valve part (not the solenoid head) in cleaner and worked it again (12v 2amp adapter). I noticed when doing this the valve doesn’t open completely, not sure if it should but definitely moves better now! Car seems to run much better than it did before with a lot less recorded misfires though still the odd few at idle!

6 hours ago, Bingodalton said:

I did not see it either. There is rubber seal around it as separate part, but not O-ring.
Maybe it is 21, but position of O-ring looks strange on the picture.

At least you can see dimension and try to find it. 

Thanks so much for the effort to get the above, it’s definitely not 5x mm so I suspect the one that they found at Skoda which is 17mmx2mm to be close to if not, the right one. It’s almost six quid for that o ring though 😂

As long as the o-rings are made from NBR, silicone isn't suited long term if there's contact with fuel/oil but will do temporarily.

 

Leave the valve soaking in a penetrant/lubricant and operate it electrically, beware of keeping it powered for more than a second or two to operate it otherwise you may damage the solenoid.

 

I am unfamiliar with the part or its operation so this is just general advice.

Edited 19 November, 20214 yr by MicMac

7 hours ago, -mike- said:

Thanks so much for the effort to get the above, it’s definitely not 5x mm so I suspect the one that they found at Skoda which is 17mmx2mm to be close to if not, the right one. It’s almost six quid for that o ring though 😂

Solenoid is bigger. You maybe think about valve itself, but it does not have O-ring.

I have measured my old one, it is 52 in fact. Dissregard measuring tape, its not perfect tool, you need to look at the middle of tape.

Thanks both for your replies and for taking the time to get the trusty tape measure out! The part pictures is not the one I need one for, to give some idea of the part it's this number for a vw 03C 906 455 A. If you take this ebay link - you can see the o-ring I need to get on the listing image : NEW CAMSHAFT OIL CONTROL VALVE FITS VW SKODA SEAT AUDI 03C906455A 1.4 1.6 TSI | eBay . Hopefully the link works, I don't know what permissions I have here!