Another 1.4TSI misfire

[roadrat]

My 1.4TSI 160 (Aug 2010 build date) has developed a misfire at 26,000 miles. It occurs when the engine is hot, full throttle between 2000 - 2500 rpm. It feels like one hesitation as the car accelerates, and on one occasion has given a flashing amber engine symbol.

The dealer failed to diagnose anything, but it's going back on Friday to have the 'usual' suspects changed, e.g. coil packs and/or injectors.

Anyone else experienced similar?

[RW1]

If the idle is smooth as usual, then more likely a coil pack playing up.

C.

[roadrat]

If the idle is smooth as usual, then more likely a coil pack playing up.

C.

RW1 - Thanks for your input. Sounds like the coil-pack changes being proposed should fix the problem!

[roadrat]

UPDATE

Car went back to the dealer today (for the second time) who once again failed to reproduce the misfire or diagnose the fault. they didn't change the coil-packs as they indicated they would last time because they say they are not allowed to change any parts under warranty without diagnosing the fault. Very frustrating! Especially as the car misfired for a good proportion of my journey home, and once again brought up the flashing amber engine warning for approx 30 seconds.

Any advice for how I can get this fixed, given the dealer's inability to diagnose the specific fault?

[RW1]

That's to be expected. Where are you in the UK?

For one thing, don't drive it in the band where its doing it, that could compund with damage.

Did you put a map on it as last you were looking?

C.

[roadrat]

RW1 - to answer your queries:-

I take your point about avoiding the band where it happens, I don't want to risk any more damage!

I am in Lancashire and the dealer is Lookers Blackpool.

The engine is standard and has never been remapped (the car has been owned by me from new).

Cheers

[RW1]

A shade further than I thought you were located....... Was thinking to give a look over, upto you if East Manchester is not too far.

C.

[roadrat]

Thanksfor that RW1.

I may take you up on the offer if the dealer can't sort it out for me on its next visit, which is at the end of the week.

[RW1]

I find it strange there isn't a logged fault code.

C.

[roadrat]

UPDATE

My car went back to the dealer with this problem for the 3rd time (lucky?). This time they kept it for 2 days.

I picked it up this evening. They managed to reproduce the misfire on test drive and traced it to number 4 cylinder - replaced the spark plug and now all is well!

Fingers crossed it stays that way.

[RW1]

Glad its sorted. Did they say/show you what was wrong with the plug? If one, then the other three

Plugs are normally lifed at 60,000Km (40,000 miles) but under Severe Operating Conditions, spark plugs are changed early.

I've now done the spark plug change and its not the plug gap as that will really change due to the spark plug design with protective tip plates. Its the insulators that give out as I have found. New plugs 3 weeks ago and an entirely different engine to drive. They came out at 17,100 miles due to the short 15 minute trips twice a day regularly done, 95% of the time.

C.

[roadrat]

They didn't show me the old plug but I expect it is a similar issue.
The car will be out of warranty next September and I will change all the plugs at the first sign of a problem after that.

Any recommendations on the best plugs & gaps to use for the 1.4TSI 160 engine?

Cheers

[RW1]

The standard plugs as spares are fine, VW part 03C 905 601A but they may be changing to 03C 905 601B. Both the same plug basically. They can also be bought as NGK PZFR6R8EG

The spark plugs will come pre-gapped to 0.8mm which is OK but I've found it better to run the engine with a gap of 0.70mm. VW workshop recommended operating setting is 0.8mm - 0.9mm which at 0.90mm is too wide as the engine murmurs misfires all the time. Bit of detail here of the early days... 1.4Tsi Revised Spark plugs

If you going to take them out yourself, then this will be useful. The Coil Pack puller has been really useful and worth the purchase for me. Never lever the coil packs out, a cheap solution is to use some fairly large tie-wraps in crossed loops.

C.

[roadrat]

Thanks RW1 - great advice!

[spoony]

I find it strange there isn't a logged fault code.

C.

I've experienced a similar problem recently, although much less frequently, and on the two occasions that it's been in to the dealers they have said there was no fault code logged. I found it particularly strange as on the first occasion I'd had the dash warning light on.

I can't pin it down to a particular range though, sometimes around the 2000rpm mark on accelerating but also at idle on one occasion.

Lookers Preston for me.

[RW1]

I can't pin it down to a particular range though, sometimes around the 2000rpm mark on accelerating but also at idle on one occasion.

Plugs is high on my list for it being the source. How many miles since new and what sort of driving, urban, main road or M/way?

C.

[spoony]

Approx 16500 since March 2010, pretty even split between urban and main road/ dual carriageway. Don't spend much time on the motorways at all.

[RW1]

I changed my plugs out early at 17,000 miles. Not because they were worn but more the insulators were past it. Plus yours will have the problematically wider gapped older type plugs discussed here. Replacing the plugs made a difference after changing at the end of Oct'12.

C.

[spoony]

Thanks for the info

[roadrat]

Hi Spoony,

I found with my misfire that it only occurred with the engine fully warmed up (i.e. after at least 15 mins of moderate to hard driving). Then I could repeat the problem at least 1 in 3 times in a full throttle acceleration from 1600 - 3000 rpm. Also seemed to be more likely when running on V-Power fuel instead of the standard 95 RON.

Since my last post, the car has been back to the dealers for a 4th time when they eventually replaced the fuel injectors on advice from VW technical. No problems since!

Hope this helps.