MK5 Golf GTI
All Things Mk5 => How to Guides / Troubleshooting => Topic started by: AJP on August 18, 2016, 10:53:43 am
-
Recently I've been getting heavy misfires under load. Engine light flashed, then stayed on. I knew the coils were old so yesterday I replaced all 4 with new R8 coils sourced from AKS. I got the car scanned and cleared the fault codes:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160818%2F2fcf8dcd1f304c5141e4a218c9f02841.jpg&hash=24892c8f3eab379e75aa16a665f0988d14043677)
Took it for a good blast and it all seemed fine. Yet today, the misfire is back. Under load, coming onto boost, and it bucks and splutters with big pops out of the exhaust.
Now I'm thinking it can't be plugs, as these were new 2k ago, fitted at Statller.
One thing I have noticed recently is a slight metallic 'rattle' or 'tinkling' with a cold engine coming onto boost - obviously on very light throttle and changing up at 2200rpm or so. I'm very careful to treat it sympathetically when it's warming up. I don't hear this noise when it's up to temp.
Reading up on this led me to the theory of a loose wastegate. So, is there a chance I have a dodgy N75, considering it shudders and misfires just as boost is building? The misfire specifically on cyl 2 tells me it's not, but I'm not ruling anything out.
Steve's working on his race engines this month so I doubt I'll be able to get it in to him any time soon.
Any ideas?
-
Have you tried swapping cyl 2 sparkplug with another?
Worth checking before splashing any cash
-
Not yet, no. Although looking again at the fault codes, the top one is 'multiple cylinders'. This is concerning me.
I'd have thought it'd only flag up multiple cylinders if multiple coils/plugs were failing simultaneously (unlikely?) or something other than coils/plugs causing misfires indiscriminately of the cylinder. I might be wrong though?
What should plugs be torqued to by the way, is it 25nm?
-
I'd look at the injectors next, well known to cause problems and you've looked at the other two already. Are any of the plugs fowled?
I had faulty injector on cylinder 3, when i pulled the plug it was soaking wet from fuel, certainly not a comprehensive test but might help.
@AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926)
-
I'd look at the injectors next, well known to cause problems and you've looked at the other two already. Are any of the plugs fowled?
I had faulty injector on cylinder 3, when i pulled the plug it was soaking wet from fuel, certainly not a comprehensive test but might help.
@AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926)
Incidentally it had an injector replaced on cylinder 4 a few weeks ago - this was to cure a bad idle with frequent misfires at idle. At that point in time, it behaved very well under load, apart from some fuel cuts from a greedy Stage 2 map that we cured with a Loba pump.
I haven't pulled any of the plugs yet. I've got the weekend off so I think I'll have a closer look at things. One thing I did notice when I was doing the coil packs yesterday was a little bit of oil on the cam cover:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160818%2Ff34e2ecfcf681a0aecc0573f6c67f4fc.jpg&hash=7acb71694bc2bb0e90235713fe2aca3d2338d118)
Is this a concern, and could this be causing an ignition problem?
And has anyone with misfires caused by a plug or coil had the "Random/multiple cylinder misfire" fault? I keep thinking it's significant.
-
I suppose the injectors can suffer different symptoms when failing , my faulty injector was perfect on idle and toddling around it only raised it's head when under heavy load, causing really bad misfiring, obviously it was flooding the cylinder with fuel.
-
I suppose the injectors can suffer different symptoms when failing , my faulty injector was perfect on idle and toddling around it only raised it's head when under heavy load, causing really bad misfiring, obviously it was flooding the cylinder with fuel.
Yeah, if I was loaded I'd have replaced all 4 injectors with new, but instead I replaced the faulty one with a used one.
It's a tricky one to second guess. Fuel and spark demand are theoretically highest under most load, right where it's misfiring. So it could be either.
But like you say, a bad injector on 2 could well be the culprit. If one failed on 4, maybe it's logical that the others weren't far behind, albeit exhibiting different symptoms. I'd be really surprised if a 3 month old plug had failed.
It had a good check over when it had the injector replaced. Compression is good, no vac leaks etc.
I hope it's a bad plug, but deep down I just know that's far too optimistic, and unlikely. Unless something has prematurely killed the plug.
-
Stranger things have happened mate, hope for you it is just a plug :happy2:
-
Cheers mate! Fingers crossed ey.
-
check the injectors are flowing correctly?. stupid auto correct :doh:
-
check the injectors are glowing correctly?.
Glowing..? You mean flowing?? It's starting to look like an injector. I'll pull the plugs at the weekend and see how they look, and take it from there.
I honestly thought I had things running properly after the new pump went in. And would have bet my arse on this being a coilpack. Oh well, at least they're ticked off the list.
-
check the injectors are glowing correctly?.
Glowing..? You mean flowing?? It's starting to look like an injector. I'll pull the plugs at the weekend and see how they look, and take it from there.
I honestly thought I had things running properly after the new pump went in. And would have bet my arse on this being a coilpack. Oh well, at least they're ticked off the list.
Yeah flowing stupid auto correct again. I have to keep editing the posts as I forget to proof read what I've typed :signLOL:
Shame you've spent loads and still in the same boat but can't be asked to get yourself a vagcom lead :doh:
-
To be fair I did look into it and I couldn't get my head round either genuine/snide lead, cost etc. I think in all honesty it's an injector I need to be budgeting for right now! I will sort it one day though, I promise :)
I've spent 80odd quid for the coil packs. The existing ones were old anyway so in theory it's a preventative measure even though they turned out not to be the cure.
The fuel cuts are fixed. The bad idle (injector 4) is fixed. So I do feel like I'm making some sort of progress. Two steps forward one step back!!!
-
My brother's got an OBDII tool, which I'm sure is capable of reading misfires on individual cylinders, so..
Plan is to scan (expecting cyl 2 again), clear codes, pull and inspect plugs, swap plugs 2 & 3, drive to misfire, scan, pray to god it comes up with cyl 3. If not, well I'll be a bit bloody gutted.
-
I'll sell you some s3 injectors @AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926) :love:
-
I'll sell you some s3 injectors @AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926) :love:
Haha, I bet you will!!
-
I'll sell you some s3 injectors @AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926) :love:
Haha, I bet you will!!
Course I would you're my best ie on here bro :drinking: :signLOL:
-
I'd probably have had these off you if I was anywhere near doing the k04 conversion. Seems a long way off at the minute though :(
-
I'd look at the injectors next, well known to cause problems and you've looked at the other two already. Are any of the plugs fowled?
I had faulty injector on cylinder 3, when i pulled the plug it was soaking wet from fuel, certainly not a comprehensive test but might help.
@AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926)
Incidentally it had an injector replaced on cylinder 4 a few weeks ago - this was to cure a bad idle with frequent misfires at idle. At that point in time, it behaved very well under load, apart from some fuel cuts from a greedy Stage 2 map that we cured with a Loba pump.
I haven't pulled any of the plugs yet. I've got the weekend off so I think I'll have a closer look at things. One thing I did notice when I was doing the coil packs yesterday was a little bit of oil on the cam cover:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160818%2Ff34e2ecfcf681a0aecc0573f6c67f4fc.jpg&hash=7acb71694bc2bb0e90235713fe2aca3d2338d118)
Is this a concern, and could this be causing an ignition problem?
And has anyone with misfires caused by a plug or coil had the "Random/multiple cylinder misfire" fault? I keep thinking it's significant.
I should have asked you or told you that the centre bolt is quite wet?. Where's the most wet part or are those bolts loose?.
-
I'd probably have had these off you if I was anywhere near doing the k04 conversion. Seems a long way off at the minute though :(
I nearly bought that K04 in the sale section last week but had a change of mind. it's too much power for a front wheel powered car.
-
I'd probably have had these off you if I was anywhere near doing the k04 conversion. Seems a long way off at the minute though :(
I nearly bought that K04 in the sale section last week but had a change of mind. it's too much power for a front wheel powered car.
I nearly linked the thread to you!
You know what, at the minute I'm starting to get used to the idea of staying k03. It just seems to be one thing after another and as much as I can afford to fix things, I can't put money away for k04 stuff at the same time :(
I dunno, we'll see. I'm just getting a bit disheartened with it all because I had the mod path all planned out, but I can't even think about upgrades right now when it's costing me money all the time just to get it running properly.
It's very much love/hate at the minute. Reminds me of my ex girlfriend.
-
I'd probably have had these off you if I was anywhere near doing the k04 conversion. Seems a long way off at the minute though :(
I nearly bought that K04 in the sale section last week but had a change of mind. it's too much power for a front wheel powered car.
I nearly linked the thread to you!
You know what, at the minute I'm starting to get used to the idea of staying k03. It just seems to be one thing after another and as much as I can afford to fix things, I can't put money away for k04 stuff at the same time :(
I dunno, we'll see. I'm just getting a bit disheartened with it all because I had the mod path all planned out, but I can't even think about upgrades right now when it's costing me money all the time just to get it running properly.
It's very much love/hate at the minute. Reminds me of my ex girlfriend.
I totally agree with your last statement :signLOL:
Tbh with you AJP, these cars are a pain in the arse and tend to get faults quick arse compared toy baby MK1 TT :signLOL: I seen to be spend img like a mad man here and the car may also be sold :thinking: madness I tell yah. he's going to come view tomorrow so who knows what will happen or maybe just a random time waster or even a hatter :notworthy:
-
I'd probably have had these off you if I was anywhere near doing the k04 conversion. Seems a long way off at the minute though :(
I nearly bought that K04 in the sale section last week but had a change of mind. it's too much power for a front wheel powered car.
I nearly linked the thread to you!
You know what, at the minute I'm starting to get used to the idea of staying k03. It just seems to be one thing after another and as much as I can afford to fix things, I can't put money away for k04 stuff at the same time :(
I dunno, we'll see. I'm just getting a bit disheartened with it all because I had the mod path all planned out, but I can't even think about upgrades right now when it's costing me money all the time just to get it running properly.
It's very much love/hate at the minute. Reminds me of my ex girlfriend.
I totally agree with your last statement :signLOL:
Tbh with you AJP, these cars are a pain in the arse and tend to get faults quick arse compared toy baby MK1 TT :signLOL: I seen to be spend img like a mad man here and the car may also be sold :thinking: madness I tell yah. he's going to come view tomorrow so who knows what will happen or maybe just a random time waster or even a hatter :notworthy:
Yeah I saw that on your build thread. I guess if you've got a plan after you sell and you don't lose too much... you've already invested a fair bit into the car with the exhaust etc though. Who knows what your plan is!!
I do plan to keep mine for a while. I remember with the old mk4 it had a new turbo and box early on in my ownership, but the last few years with it were reliable and enjoyable. I only sold it because I got the itch for another Audi Coupe, which in turn was a dog, and led me to this mk5. Which aint a dog at all, but it's certainly throwing more bills at me than I'd expect. Pertinently or not, all this hassle came after going Stage 2. But anyway, if it means that the first couple of years with it are spent ironing out problems, and the next 5+ are fun and reliable, then so be it. I'm not giving up yet!
-
I'd look at the injectors next, well known to cause problems and you've looked at the other two already. Are any of the plugs fowled?
I had faulty injector on cylinder 3, when i pulled the plug it was soaking wet from fuel, certainly not a comprehensive test but might help.
@AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926)
Incidentally it had an injector replaced on cylinder 4 a few weeks ago - this was to cure a bad idle with frequent misfires at idle. At that point in time, it behaved very well under load, apart from some fuel cuts from a greedy Stage 2 map that we cured with a Loba pump.
I haven't pulled any of the plugs yet. I've got the weekend off so I think I'll have a closer look at things. One thing I did notice when I was doing the coil packs yesterday was a little bit of oil on the cam cover:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160818%2Ff34e2ecfcf681a0aecc0573f6c67f4fc.jpg&hash=7acb71694bc2bb0e90235713fe2aca3d2338d118)
Is this a concern, and could this be causing an ignition problem?
And has anyone with misfires caused by a plug or coil had the "Random/multiple cylinder misfire" fault? I keep thinking it's significant.
I should have asked you or told you that the centre bolt is quite wet?. Where's the most wet part or are those bolts loose?.
I missed that reply mate, sorry.
Yeah that's why I put the photo up, I took it before I took the coils out, half expecting 2 or 3 to be covered in oil, but they weren't, just a little spot on each of the 4. Although, it might make sense that plug 2 is fouled if there's enough oil getting down there.
If I pull the plugs and 2 is wet with just fuel I'm still thinking injector. But... if it's oil and it's simply fouled from above, then maybe a new cam cover is in order. I'd take that over injector.
I didn't try the bolt. Not sure I've got a torx bit to fit that. Do you know what size it is?
-
I'd probably have had these off you if I was anywhere near doing the k04 conversion. Seems a long way off at the minute though :(
I nearly bought that K04 in the sale section last week but had a change of mind. it's too much power for a front wheel powered car.
I nearly linked the thread to you!
You know what, at the minute I'm starting to get used to the idea of staying k03. It just seems to be one thing after another and as much as I can afford to fix things, I can't put money away for k04 stuff at the same time :(
I dunno, we'll see. I'm just getting a bit disheartened with it all because I had the mod path all planned out, but I can't even think about upgrades right now when it's costing me money all the time just to get it running properly.
It's very much love/hate at the minute. Reminds me of my ex girlfriend.
I totally agree with your last statement :signLOL:
Tbh with you AJP, these cars are a pain in the arse and tend to get faults quick arse compared toy baby MK1 TT :signLOL: I seen to be spend img like a mad man here and the car may also be sold :thinking: madness I tell yah. he's going to come view tomorrow so who knows what will happen or maybe just a random time waster or even a hatter :notworthy:
Yeah I saw that on your build thread. I guess if you've got a plan after you sell and you don't lose too much... you've already invested a fair bit into the car with the exhaust etc though. Who knows what your plan is!!
I do plan to keep mine for a while. I remember with the old mk4 it had a new turbo and box early on in my ownership, but the last few years with it were reliable and enjoyable. I only sold it because I got the itch for another Audi Coupe, which in turn was a dog, and led me to this mk5. Which aint a dog at all, but it's certainly throwing more bills at me than I'd expect. Pertinently or not, all this hassle came after going Stage 2. But anyway, if it means that the first couple of years with it are spent ironing out problems, and the next 5+ are fun and reliable, then so be it. I'm not giving up yet!
I'll be losing a lot as I paid £6850 last year and now new alloys new exhaust and youve seen the rest in my build thread. what to do as the guy has just called now and seems desperate :thinking: he said he's just sold an R32 57 plate for 9500 so he needs a car urgent.
I hate a love hate relationship with with car atm but reading how people are having issues with thier cars and the value is sh*** I'm thinking get rid now whilst I can?. Once you start moding is when the problems start arising and faults get the better of you. my tt :signLOL: never had these issues even after the map and mods :grin: sold it for peanuts though. :sad1:
-
I'd look at the injectors next, well known to cause problems and you've looked at the other two already. Are any of the plugs fowled?
I had faulty injector on cylinder 3, when i pulled the plug it was soaking wet from fuel, certainly not a comprehensive test but might help.
@AJP (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11926)
Incidentally it had an injector replaced on cylinder 4 a few weeks ago - this was to cure a bad idle with frequent misfires at idle. At that point in time, it behaved very well under load, apart from some fuel cuts from a greedy Stage 2 map that we cured with a Loba pump.
I haven't pulled any of the plugs yet. I've got the weekend off so I think I'll have a closer look at things. One thing I did notice when I was doing the coil packs yesterday was a little bit of oil on the cam cover:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160818%2Ff34e2ecfcf681a0aecc0573f6c67f4fc.jpg&hash=7acb71694bc2bb0e90235713fe2aca3d2338d118)
Is this a concern, and could this be causing an ignition problem?
And has anyone with misfires caused by a plug or coil had the "Random/multiple cylinder misfire" fault? I keep thinking it's significant.
I should have asked you or told you that the centre bolt is quite wet?. Where's the most wet part or are those bolts loose?.
I missed that reply mate, sorry.
Yeah that's why I put the photo up, I took it before I took the coils out, half expecting 2 or 3 to be covered in oil, but they weren't, just a little spot on each of the 4. Although, it might make sense that plug 2 is fouled if there's enough oil getting down there.
If I pull the plugs and 2 is wet with just fuel I'm still thinking injector. But... if it's oil and it's simply fouled from above, then maybe a new cam cover is in order. I'd take that over injector.
I didn't try the bolt. Not sure I've got a torx bit to fit that. Do you know what size it is?
no need to be sorry as I sometimes miss a post in a thread.
If the oil in in the chamber that shouldn't and wouldn't cause the misfire unless it's drowned as ive seen some really bad cam cover leaks on my time working on cars.
You won't find fuel in the chamber where plug can be seen after removing the coil pack. Seriously man you need vagcom rather than guessing what if as this will eliminate injectors or point toward the failed one. loba but no vagcom?. :thinking: £40 if that for a copy of vag and he'll be your best friend for life oe the ownership of your motor.
I'm sorry but I don't know although it looks like a torx 35 from the picture but I could be wrong. torx set ebay less than a tenner my friend. most enthusiasts have a basic tool kit so I think you should also keep this in mind and maybe invest in a few bits if you're planning on dyi :happy2:
I wonder if the injector seal is leaking as my tt did that on number 2 cylinder and once replaced it stopped hissing at me lol £4 from Audi per O ring although the tfsi is different.