rickdonald 10 Posted October 24, 2011 Hi, Just after a little advice, about a fortnight ago my VR started to what feels like a misfire, at around 4200rpm when accelerating. It doesnt happen every time but seems to be more so in higher gears, eg 3rd, 4th or 5th. Its most noticable "on my private road" in 5th, it really struggles to get past 4200rpm, just really stutters and judders/misses, then its fine when you take your foot off. In lower gears there is a slight judder as it misfires around 4200rpm, then seems fine higher up the rev range. I have had a look on VAG-COM but there is nothing recorded (kept the engine running after it happend, as to keep the codes in memory). I'm just after abit of advice on what it could be? or if anyone has had similar, I have had a search and found other posts but nothing I can really relate to or which gives a solution/ideas etc. The plugs have been changed about 9 months ago, and the ones I took out where fine, (no or very little oil on them) also at the same time I replaced the fuel filter. Not to sure on the leads and coilpack, am I right in thinking I can just check the resistance of the leads to see if any of those are faulty? If so what values am I looking for? I know its not a massive problem, and most of the time isn't noticable becasue its not driven that hard. Its just when the urge does take you, and you press on, its abit worrying and dis-heartening! Cheers for any help Rick Quote Share this post Link to post Share on other sites
Supercharged 2 Posted October 24, 2011 Have the chains ever been done? Quote Share this post Link to post Share on other sites
rickdonald 10 Posted October 24, 2011 Have the chains ever been done? Ha, nooo dont say the "C" word! I dont think they have mate, or at least there is no history of it. Which I know is bad because its getting on for 160,000 now. It is on my list of things to do (along with everything else), but its going to be a while before I can get the time to take it off the road for that long to do them, and im psyching myself up to do it myself. Dont have the money really to take it to a garage. Why do you say chains anyway? they arent noisy and dont rattle, which I know doesnt mean that nothing is wrong. Do you think it could be related? Quote Share this post Link to post Share on other sites
Supercharged 2 Posted October 24, 2011 Just wondered if the timings slipped - just seems strange that a code isn't logged... Quote Share this post Link to post Share on other sites
Simon vr6 10 Posted October 24, 2011 Hi Rick I had exactly the same problem! Changed all the spark plugs and HT leads and still had the problem. Took it to VW and all they did was clean the air box, didn't help at all! So I decided to change the coil pack and found a slight crack in it, replaced and had no problems since. Hope this helps Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 24, 2011 He means if the chains are so badly borked to have caused one or both of the cams to slip round a tooth, that would explain the power loss / misfiring. I doubt it personally but you should really budget for their replacement. If nothing has come up on VAG-COM, I'm afraid you will have to systematically check / replace things, such as the MAF, coilpack, HT leads etc. Quote Share this post Link to post Share on other sites
Roger Blassberg 0 Posted October 24, 2011 What plugs are you using? I had a set of Bosch something-or-others, straight out of the box they were truly dreadful and misfired exactly as you describe, despite being the ones recommended by Bosch. I replaced them with the standard NGK items BKR5EKU from Sparkplugs.co.uk and the difference was like night and day. As has been said many times, even though your chains are apparently quiet, after 160 000 miles the top tensioner will be worn and it's quite likely that at least one of the chain guides will be damaged too. Best wishes RB Quote Share this post Link to post Share on other sites
rickdonald 10 Posted October 24, 2011 Yer I have read quite alot into the chain replacement and realise it is no excuse that it isnt noisy, it's just purely as "fishwick" says a need to budget for their replacement. Also my Plugs are the BKR5EKU, again from a recommendation from "fishwick". I would have thought if the timing had slipped at all though it wouldn't run so smoothly throughout the rest of the rev range. I will have a look at the ht leads and coilpack and and look for any service history on them, and then have a look see how much it's going to cost to do the chains and whether I would feel confident enough to do them myself! Thanks for the help guys Quote Share this post Link to post Share on other sites
rickdonald 10 Posted October 25, 2011 Ok so you have got me worrying now, how badly would it run if the cams had slipped? I would have thought it would run badly all the time, if at all? Im going to have a look at the leads and coilpack when I get time, then I guess time to bite the bullet and take the rocker cover off to inspect what sort of state the tensioners are in. Would you recomend me to tackle the chains myself? If I budget myself a weekend + monday & tuesday using the guides on here and VWVortex? considering I have never really done anything that in depth before, haven't got a garage to work in so it will have to be done on the drive, but like to think I'm not a complete muppet with a spanner. I know its a ridiculously open question, but just looking for advice from people who know. Cheers for the help Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 25, 2011 You'd be surprised. The first time I fitted cams to my VR6 I managed to get one them a tooth out (easily done!). It drove fine everywhere except 4000rpm onwards funnily enough. I didn't misfire but it was completely gutless. Start with the simple things first like the leads and coilpack etc and we can go from there! Quote Share this post Link to post Share on other sites
rickdonald 10 Posted October 31, 2011 Had a look at the coil-pack and leads at weekend, and from the looks of it the coilpack has gone, seems to be a common issue looking round on the forum the last few days, with the weather deteriorating. [ATTACH=CONFIG]49907[/ATTACH] Had a couple of nice cracks around the side, and from doing a bit of reading around it seems a bit too far gone to try and fill with epoxy to repair. So will have to get on looking for another. Although just taking it off, giving it a clean and filling the gaps with a bit of WD-40 and then covering in Vaseline, it seems to be running a lot smoother. Cheers for the help guys Quote Share this post Link to post Share on other sites
Supercharged 2 Posted October 31, 2011 Jesus - yeah I think you've found the fault! Usually you have to look hard to see any hairline cracks but never seen one that bad before... Quote Share this post Link to post Share on other sites
rickdonald 10 Posted November 3, 2011 Fitted another coil-pack today, second hand although in good condition, or looks it anyway (no cracks). But I have put it on and taken it for a drive and its still no better, in-fact a little worse. It seems to be really struggling when I put my foot down on the motorway. Just seems to start higher up the rev range when your at full throttle. Taken off the leads and checked the resistances, all seem ok ranging from about 5.6 kOhm to about 6.3. although lead 4 with is 6.3kOhm seems to have a bit of a bad contact at the plug end. The leads seem quite "stiff" like they have been well and truly baked in the engine bay for a while, so I'm guessing they are fairly old., so not sure what to do, as in look at getting some "blue igniters" leads, or whether to check anything else. Any suggestions? Quote Share this post Link to post Share on other sites
