160 misfire and rough idle

[josheades]

My car has been rough idling and slight misfiring for a while now however I was unable to find any codes, I took it to the local specialist and he couldn't find anything, I started with the obvious to see if I could fix it, I started with spark plugs, this seemed to work for a few days then it came back, after a few weeks of being very careful with it the Mel light eventually flashed for a few second then went off, I then plugged it back into the computer and discover I now had a fault code, the code was P0106 which is manifold absolute pressure, I have googled the symptoms of a faulty map sensor and they seem to match what my car is doing,
Has anyone else experienced this and can help me in the right direction as it could be leaks faulty sensor etc....
Many thanks
Josh

[TheRustySheriff]

Read my thread titled 'Rough Running' and see if your symptoms match mine.

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[greg7728]

Sorry to re awaken this, today mine (tsi 160) decided it had enough. Epc and engine management light flashing then engine management light stops flashing and epc remains. Has felt a bit rough for a while - VW said its looking like a mis firing. Absolutely shocked. 24k miles and engine issue. Had the dsg clutch pack replaced when I bought her at 15k miles, think I have have to fix her up and get rid had such a poor experience 2010 1.4 tsi most of the threads on here are saying new pistons and most of the engine replaced. Deeply saddened that my girl having issues so early in her life. Guess I'll need to contact the warranty people and prepare for battle.


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[greg7728]

https://vimeo.com/148119745


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[greg7728]

Problem is intermittent anyone got any ideas why it would do it with all lights then lights all go and running fine?


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[blower]

Misfires are the bane of this engine in one way or another...

I have the same engine and even though i've not had misfires since i bought it with 30k miles, i did some preventative maintenance - buying latest revisions sparks and gapping them to 0.7mm.

This is the order i would do things when this engine misfires:

Spark plugs

Make sure plugs fitted are the latest revision 03C905601B
The original plugs in this engine were gapped too big, and were platinum. The latest revisions are 0.7 to 0.8mm and iridium (smaller tip = better spark, iridium also longer lasting)
As plugs age the gap increases, these engines will misfire if the gap increases much beyond 0.8mm - it is recommended to regap even new sparks to 0.7mm (or check if they at 0.7mm)

Coil packs

It is somewhat common for TSI engines (1.4 and 2.0) for the coil packs to start to randomly fail. There were also some weeks of manufacturer that had faulty coil packs.
To check them you really need access to VCDS or a scantool to see which cylinder the misfire is being detected on. If its always the same cylinder you can play a game of swapping coil packs around and see if the misfire moves to a different cylinder - you then know which is fault and which to replace. Alternatively if you suspect coil packs just replace the lot (expensive)

Compression

If sparks and coils fine, then next step would be to check compression of each cylinder - you will need a compression tester for this....although if you do find low compression on one of the cylinders then it's almost certainly going to be a cracked piston, which as you know is a disaster (new engine or rebore and new pistons)

Injectors

It's hard to directly test if an injector is blocked or not spraying correctly whilst its in the engine.....basically if you have ruled out all the above then it's probably an injector that's failing / blocked. Again VCDS/Scan tool will indicate which cylinder the misfire is on and hence which injector to suspect. Before paying out for a new injector and the large amount of labour to replace it, if you have got this far then its worth running a load of injector cleaner through the tank.


Other possible causes are timing chain stretch - although again VCDS would indicate this.

[blower]

Problem is intermittent anyone got any ideas why it would do it with all lights then lights all go and running fine?

Thats how misfires are detected and operate on VW cars....the ecu is always on the lookout for misfires - it counts misfires over a small time frame, when it exceeds a certain threshold it will throw a code, put the engine management light on and cut power drastically. If after 30 seconds or so the misfires have dropped off it will put the EML light off again and resets its threshold counter...the cycle will then continue with it putting it back on if a load of misfires happen.

[greg7728]

Any idea what may have caused this and would u say it's safe to drive to a garage I thought if it was timing chain tensioner related like the misfires on this engine is commonly known for it would be all the time. Would a normal diagnostic show the reason for mis Fire I.e coil or am I looking at engine parts being removed to see what's going on? I thought if it was the timing chain issue the engine would be permanently running poor. But was fine when headed back home


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[greg7728]

Thanks for all your advice blower, I'll get on to a garage tomorrow and see what they say. Warranty company are going to be difficult I'm sure of it. Hope it's something simple like a coil or spark - I wasn't in the car when it went wrong it scared the hell out of my wife though.


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[blower]

Any idea what may have caused this and would u say it's safe to drive to a garage I thought if it was timing chain tensioner related like the misfires on this engine is commonly known for it would be all the time. Would a normal diagnostic show the reason for mis Fire I.e coil or am I looking at engine parts being removed to see what's going on? I thought if it was the timing chain issue the engine would be permanently running poor. But was fine when headed back home

Yeah its unlikely a timing chain issue - as you say it would be running poor all the time. It's last on the list of potential causes.

To hazard an educated guess - i would say its probably something as simple as the spark plugs.
Your spark plugs when new were probably on the edge of operation and gapped just over 0.8mm, over time this gap has increased and the misfires have increased to the point they now putting the EML on.

Without knowing the history of the car this is a guess - do you know when the sparks were last changed? and if they were changed by VW or a 3rd party? (reason being is its common for 3rd party to put in wrong gap sparks as they take out the old factory ones which were wrong from the factory and put in the same...or look up the part and put in equivalent which again is probably wrong gap size)

[greg7728]

The car has 24k miles and was services by VW every 4-5k (1 year) book says sparks were done at 15k but not sure if they really were as VW tick box seems just be tick random things on the page . I'm going to ring my garage and see if they can run a diagnostic and see what the code said, and go from there I guess. Thanks for your advice, sparks will be a good place to start, I just don't want to get turned over by VW like I did with the clutch pack, went a 14k and they offered a token goodwill but not on labour (125 an hour was the bulk of the bill) - wish me luck!


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[blower]

Yeah they rip you off - and they should do all DSG boxes for free as the damn thing has serious design flaws.

For reference mines a dsg too, i'm at 52k miles - in that time this car has had 2 replacement clutch packs (so i'm on my 3rd if you include the factory), also a new mechatronics. It's going well on its 3rd, new revisied clutch pack and mechatronics but time will tell if it starts to judder in 2nd gear again.

I do love my car though, but these engines and dsg combo's are not for the faint hearted. Mines recently been remapped with APR Stage 1 - goes like a rocket now
Knowing that these engines would blow even on stock i have done a lot of upgrades (new revision coil packs, full set of new revision injectors, new revision HP fuel pump, sparks) and upgraded the intercooler.....all this for a stage 1 map, just so it don't blow up.

It may blow up anyway - but if it does it would have done so anyway - map or no map. My thinking is if its going to go, might as well go in style!

Good luck with yours - as i say check the sparks part number...if its not 03C905601B then either replace with 03C905601B or NGK SIZFR6B8EG

[moulin12]

As has been noted, there are a number of theories/possibilities on the cause of the dreaded misfire.

My 160, with 30K on the clock, had always been a bit lumpy at idle since the time of buying it. Having failed it's emissions at MOT, the dealer went through weeks of checks and (under the direction of VW) replaced plugs, coils and injectors, in that order, before finally diagnosing the emissions failure as an issue with the secondary lambda sensor. However, during the process the technician did note that the lumpy idle/misfire issue had been cured by the change in injectors (not plugs or coils)

I'd also had the DSG clutch replacement experience, so felt it was time to let the car go.

Not sure which warranty you have but all of my work was carried out at no cost under VW extended warranty (along with a replaced suspension spring!). Interesting that you had to contribute to the DSG replacement - mine was fully covered by goodwill/extended warranty.

[greg7728]

I bought the car from non VW garage came with VGS warranty - only pay 45 an hour labour and don't cover diagnostic. VW labour charge is 125 an hour so I'd be reluctant to take it there. It's going in to my usual garage which I trust much more than VW for diagnostics - software to clear codes and see which cylinder is mis firing then go from there I guess but they don't deal with warranty so I'd be paying and getting reimbursed, hoping it's a plug or coil - not sure any garage has a 45 an hour labour rate any more. Could end up getting expensive.


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[greg7728]

Just back from the garage and was mis Fire in cylinder 4, garage advised strange hasn't done it since - cleared the code and advised if does it again Coke back and will start taking plugs/coils etc off however didn't want to replace parts unnecessarily. Least I know what cylinder it was so where to start. They said unlikely to be timing chain issue as would be mis firing all the time as once chain is stretched its stretched. Thinking of replacing the plugs as a precautionary measure as above, and fingers crossed I don't need to do anything else.


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[greg7728]

I'm thinking of replacing the Sparks and coils as a matter of course not as cheap as I thought it would be though but hey ho. Hopefully it won't have any more misfires once I've changed that out. If it does at least I'll know it's not something I can sort and will need to go via warranty for injector or compression or something worse. Anyone know the coil part number - the plugs are £16 each!


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[blower]

That seems a bit steep on the price.

Get these, they are exactly the same NGK part number as the VW 03C905601B

http://www.ebay.co.uk/itm/161786155017" onclick="window.open(this.href);return false;

The latest revision coil pack part number is 036905715G

They are fairly expensive - VW will want £40+ each

[blower]

Try the sparks first - if you want to test coil packs, i actually have a couple of 036905715F ,they were the coil packs used up until about 2011/2012 and probably the part number you have in there at the moment. The newer revision G have a slightly stronger spark generation but it's not necessary unless you plan to remap.

They have about 10k miles on them and work perfectly - i swapped them out of my engine as i been doing various upgrades for a remap. They're on ebay, you can have em for £10 each.

But do the sparks first as more than likely that's the cause of the problems.

[greg7728]

Cheers I'll change out the plugs before doing anything else. Hasn't had any issues since last time so not sure if to just leave it after I've done plugs and if it happens again then attack the coils


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[greg7728]

Compression test done today and stated no issues, slightly lower compression on one but mechanic said its neglegable and not indicative of any issues and nothing to worry about. He said its most probably a degrading coil - so, new VW sparks and coils (cheaper from VW parts guy after a little haggling than eBay or TPS ) - so I'll fit these in the week and hopefully that's the end of it. As for the slightly lumpy idle, I guess that's just how this engine is, may have to just live with it.


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