Issue With 2.0 TDI VRS Skoda Octavia - Judder On Acceleration

[bloodiedathame]

Do you have any links to what you mean??

Sure. The OBD port is used for diagnostics, but you can buy your own and pay as little as £5 to God knows what. I think I paid £7 for one and it packed up after a year. All the OBD reader does is get plugged into your car, and feed data to the apps.

First app I use is: https://play.google.com/store/apps/details?id=org.prowl.torque&hl=en_GB which is great for diagnostics and live data. It can even keep a log of readings and speed etc so you can pinpoint exactly where you were seeing problems (ie throttle position full on, and no change in acceleration).

The second is the VAG DPF app, which will, if your car is supported, give you information about the state of the DPF: https://play.google.com/store/apps/details?id=com.applagapp.vagdpf&hl=en_GB

It's worth noting that DPFs are a complete PITA, what's happened to you happened to my Bother in laws C-MAX, and he ended up doing what another poster did, flogging it to WBAC when it was warm and the error messages were clear.

 

[Tee Hee Johnson]

Sure. The OBD port is used for diagnostics, but you can buy your own and pay as little as £5 to God knows what. I think I paid £7 for one and it packed up after a year. All the OBD reader does is get plugged into your car, and feed data to the apps.

First app I use is: https://play.google.com/store/apps/details?id=org.prowl.torque&hl=en_GB which is great for diagnostics and live data. It can even keep a log of readings and speed etc so you can pinpoint exactly where you were seeing problems (ie throttle position full on, and no change in acceleration).

The second is the VAG DPF app, which will, if your car is supported, give you information about the state of the DPF: https://play.google.com/store/apps/details?id=com.applagapp.vagdpf&hl=en_GB

It's worth noting that DPFs are a complete PITA, what's happened to you happened to my Bother in laws C-MAX, and he ended up doing what another poster did, flogging it to WBAC when it was warm and the error messages were clear.

I really like my odb2 reader and torque (actually forscan when I had the Fiesta).

BUT if the garage has already hooked it up to a proper odb2 scanner an diagnosed all this, I dont think my £4 reader would be up to much more than the proper tools were.

 

[hominid]

It's a fueling issue, most likely an injector fault as it's a matter of when, not if, these go. Given that I'm very surprised that the garage hasn't found it as you can tell with vag-com by measuring a few blocks at idle if there is something wrong or not.

If you can, get someone to measure blocks 04, 13 and 14 and post it up here - that will tell you if something is not right with the injectors(the readings should be as close to zero but also balanced(almost the same)) - if not you may have an issue. These are not cheap, if it's the ones I'm thinking, as they are upwards of £400 a piece and it's recommended that you get the set done as it's only a matter of time until the others go.



//edit, Also I think there was some sort of warrantee replacement on these, but you may be out of luck due to age..

 

[bloodiedathame]

I really like my odb2 reader and torque (actually forscan when I had the Fiesta).

BUT if the garage has already hooked it up to a proper odb2 scanner an diagnosed all this, I dont think my £4 reader would be up to much more than the proper tools were.

True, I used it more for monitoring and logging than checking error codes.

One thing I did think while on lunch was that I remember reading the MAF sensor can cause DPF issues. I don't think you mentioned checking this.

 

[Mercenary Keyboard Warrior]

Off topic

Whats the result of a bad compression test on a diesel, would that result in unburnt/poorly burned fuel? (Not saying this is the OP issue, just came to mind)

 

[hominid]

Off topic

Whats the result of a bad compression test on a diesel, would that result in unburnt/poorly burned fuel? (Not saying this is the OP issue, just came to mind)

That would normally mean a hardware issue, mainly catastrophic stuff(holes in pistons, broken rings, bent/broken valves, head-gasket). Saying that it's normally fueling because the engine combustion chamber is sealed and the only thing added it the fuel(at the right time). There is no spark timing to worry about and as long as the valve timing hasn't skipped a tooth or two on the timing belt then it's always, mostly, fueling issues - what's causing the fueling issues is what need a PROPER mechanic to take a look at the thing.

The guy that the OP took it to is not a proper mechanic, he's a technician, there's a difference. He can read the on-board computer and it tells him what's wrong, he changes it, rinse repeat until problem gone. The OP need to take it back and demand that a master-tech takes a look at the thing, considering he's already spent over £1k and it's not fixed - it's the least they can do!

 

[Scania]

Faulty injector is that a big job as in head gasket be removed? Or what ??

Shouldn't be anything as involved as that,depends on the particular application though.

True, reading back i didn't really describe what I mean, I mean the sorts of circuit testing thats going on now, so something up with that whole circuit which triggers a fault and hence a reaction from the ECU, which indirectly causes a bad burn, via incorrect fueling (could be timing, misreading temp sensor etc)

Fair point, one of the few downsides to ECUs in vehicles is they can throw up some baffling behaviour when something goes awry.

I was wondering if you were confusing a glow with a spark plug tbh.

 

[Dangerous Dave]

On some diesels the glow plugs are used during a DPF regen if they are faulty it can prevent the regen from running. I don’t think that is the case for the OP as it wouldn’t cause a new DPF to fill up in 8 miles.

 

[FTM]

have you posted on Briskoda.net

a whole lot of knowledge on there