Misfire just on gear change

[redscout]

Get Bluetooth dongle and carista app to check for codes. Will show up most things. Ive been very impressed with it. Bluetooth obd reader and carista app can be had for about £20

 

 

Good tip. Carista is worth its weight in gold. So much you can do with it

Sent from my Galaxy S5

 

Cheers fellas, just ordered a reader which seems to offer real time monitoring - it'll be interesting to see how that works and it'll keep me busy over Christmas!

[Almal]

You say the vehicle had/has a miss fire which was the original problem? If the timing was out for whatever reason and possible valve to piston contact occurred then any slight damage could cause a miss fire more so just under load. Does the engine timing chain sound slightly noisy for any reason? Sorry all the questions, what was the original repair carried out?

[redscout]

You say the vehicle had/has a miss fire which was the original problem? If the timing was out for whatever reason and possible valve to piston contact occurred then any slight damage could cause a miss fire more so just under load. Does the engine timing chain sound slightly noisy for any reason? Sorry all the questions, what was the original repair carried out?

Hi Almal

 

The original repair was stage 2 rebuild. This included new pistons, rings, con. rods, timing chain, tensioner, and camshaft I think - these were the cause of the original problem which was massive oil consumption. Skoda carried out these repairs but when I got it back it sounded to be running noisily so I took it back. Skoda scanned it and said all was well. The car broke down within a week and went back to them - they replaced camshaft adjuster valve. Since this time it has been misfiring. It's been back twice since- the first time they took it apart and found a broken mesh of some sort on the variable valve timing which they repaired and assured me that the timing was within spec (but only marginally). The car started running better but still misfiring (only after gear changes still). It went back again, Skoda had it for 3 weeks, plugged it into diagnostics, tried donor plugs and coils, took the inlet manifold off to inspect valves (after consulting 'technical') and then recommend head/valve clean but offer no guarantee that this will fix it. The cars since been to an indy who tried VAGCOM and VCDS only to report that it wasn't an electrical problem - however these tests were performed stationary so I'm not sure whether I've gained any insight. I think what I really need is the car plugged in whilst driving and gear changing to see if the issue can be pinpointed.

 

So, the critical moment in these events seems to be the camshaft adjuster valve failure, although the car wasn't right before then. I'm not clear what the camshaft adjustor valve does and whether the break down could have damaged valves etc.