TimDoc 0 Posted June 23, 2011 VR6 running on 5 cylinders, went and purchased new leads and plugs, not sorted, so new coil pack, worked for around 5 minutes and then killed it! Now back on 5 cylinders and lumpy again, 20 mins later suddenly picked up again and full power for around 20s, then died again and back on 5 cylinders. Got it home. What kills coil packs or could cause it to run on 5 only with new plugs and leads and coil pack? Faulty wiring?? Bad connection?? Tim Quote Share this post Link to post Share on other sites
davidwort 0 Posted June 23, 2011 most coil packs or individual (on top of plug) coils seem to crack their insulation/resin through the continuous cycle of heat and cold on an engine, and then with the insulation broken down, moisture gets in, they short and die. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 23, 2011 (edited) I don't reckon your coilpack is the problem here. Take your plugs out and check for oil fouling. The one which is wet will be the cause of the misfire. If all 6 plugs are dry, suspect a dodgy lead as you say. VR6 coilpacks are just 3 coils in reality. 1 & 6 fire at the same time, as do 5 & 2 and 3 & 4. So if one of the coils goes down, it's paired cylinder will also misfire. I've never had a VR6 coilpack die on me. Replaced them a few times over the years due to misdiagnosis, but they are far more reliable than they're given credit for. As David says, it's just age and use that eventually gets them, as with most things car related. Edited June 23, 2011 by Kevin Bacon Quote Share this post Link to post Share on other sites
VR6Pete 0 Posted June 23, 2011 yep, I mirror what kev says, i had a slight misfire after rebuilding my engine, all new plugs, leads etc.... noticed a few big cracks in the coilpack, got a beru and now silky smooth again, but i wouldnt expect that to result in yours only running on 5. As kev says, check plug / lead :) Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 if there is oil fouling what does that mean? gasket gone?? Tim ---------- Post added at 10:08 AM ---------- Previous post was at 10:03 AM ---------- plugs and leads are all new! Hoping theres no issues there, when i removed the ht's one at a time whilst the engine was running, the only one that didnt cause the engine to stutter more than it was already was lead 2, but the old plug in lead two was the cleanest when removed. It was 5 and 6 that had oil covered plugs. Tim ---------- Post added at 10:09 AM ---------- Previous post was at 10:08 AM ---------- no cracks in the old bosch coil either Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 23, 2011 5 and 6 are on different coils and it's unlikely both of those were down. Oil fouled plugs means bore wear I'm afraid. 1 and 6 are common for it. 5, less so. It's a gradual process as oil gets into the combustion chamber and gradually fouls up the electrode. You can usually get a temporary cure by revving the crap out of the engine and the heat burns the deposits off, but get back to short journeys again and it will foul up again cause of the cooler cylinder temps. A nice long journey can also have the same effect. VR6s don't especially like being pootled around. They need heat and revs :D Anyway, check your plugs first and we'll go from there...... Quote Share this post Link to post Share on other sites
Critical_Mass 10 Posted June 23, 2011 Had similar issue with my VRs old engine. Plugs were fouled with oil causing misfire. Oil fouling is generally one of 2 things, either piston rings or steam seals. Any particular plug thats fouled? Do you get blue smoke from exhaust at all? Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 no blue smoke, will post a picture of the plugs removed the other day t ---------- Post added at 11:09 AM ---------- Previous post was at 10:40 AM ---------- right - heres the pics cylinders numbered 1 2 3 4 5 6 Any suggestions Tim Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 23, 2011 Photobucket. I'll have to have a look at them at home later. Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 cheers dude - progression though - had issues with the new coil pack as it wouldnt release the leads - they were literally stuck onto it, snapped one trying to get them off, unbolted the pack with leads attached and took the whole lot to GSF, spoke to the manager who amazingly replaced the leads for me for free (and gave me more expensive ones at no extra charge!) and fully refunded the coil pack, no longer out of pocket with broken equipment! Guessing photobucket doesnt work for you FishWick at work, thanks for looking anyway mate. Tim Quote Share this post Link to post Share on other sites
VR6Pete 0 Posted June 23, 2011 Those plugs have seen better days! :) Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 funnily enough - they are only around 9 months old! now replaced though! thinking the root cause needs sorting, which might be engine internals?! T Quote Share this post Link to post Share on other sites
dannyboy 0 Posted June 23, 2011 6 looks covered in oil and deposits-bad 2 and 5 are good Rest is covered in deposits,maybe from burnt oil or coolant. Valve guides worn maybe? Them plugs deffo need to be replaced,deposits are whats probably causing the misfire.You need to find out whats causing the deposits,more likely to be oil or coolant Ive never seen a spark plug gap that big before... maybe just my imagation Quote Share this post Link to post Share on other sites
Critical_Mass 10 Posted June 23, 2011 See my post. Its burning oil by the look of it, that is exactly how my plugs looked. Stem valve steals or piston rings. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 23, 2011 Yep, just seen the pics and as said already, start saving for an engine rebuild! Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 how much are we talking re re-build, guessing this would be new chains and guides, new gaskets - new seals and piston rings - how much is a ball park figure if i do it all myself?? And how much if i give it to someone else? Tim ---------- Post added at 06:37 PM ---------- Previous post was at 06:37 PM ---------- could this just be a gasket? Quote Share this post Link to post Share on other sites
Critical_Mass 10 Posted June 23, 2011 (edited) Suppose Kev could correct me if im wrong but if its stem seals then a rebuild would sort it, if oil is getting passed the piston rings then its more likely that the bores have oval'd (VRs are prone to it) and a new head will be needed. Chains and guide wouldnt NEED doing necessarily, but seen as its all out you may as well. Not sure how much for parts and labour etc. Another option would be an engine conversion. Or a refurbed VR engine from Vege - which was a shade under £2k, when i got mine done in 2008 and thats just for the engine - you'd have to transfer the ancillaries etc over to new engine. Thats also on a exhchange basis and also only available when Vege actually have a VR engine. Edited June 23, 2011 by Critical_Mass Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 any way to test between stem seals or piston rings as the source before taking engine apart - compression testing? Tim Quote Share this post Link to post Share on other sites
carrots 1 Posted June 23, 2011 mate had same prob with his vr6 .engine was f--ked Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 thanks for the constructive comment! Gonna have a look and see inside me thinks! Tim Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 23, 2011 A 'leakdown test' is the only way to pinpoint the wear without stripping the engine down. Basically you put each piston onto TDC in turn and blast compressed air into that cylinder's plug hole. If you hear / feel hissing noises at the top of the engine and not the bottom, it's valve guides. If you hear the air escaping at the bottom of the engine, it's worn bores. And if you're really unlucky you'll hear air escaping at both ends! Cylinder head overhaul will set you back around £400+VAT at a specialist Bottom end overhaul = considerably more. Just the pistons/rings themselves are £600 ish and there's often a month's wait from Mahle for them. About £2300 last time I looked, so you're looking at around £3K for a top and bottom rebuild at a specialist, or £2K from an engine supermarket like Vege as Critical mass said. Looking at your plugs I'm fairly confident the motor is past it, sorry. Maybe consider a 24V conversion? Or obviously you could hunt down a good s/hand 12V and drop that in. Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 23, 2011 Might be the end of my corrado - somber day this is indeed! If only i had sold it a month ago as planned! Time to make plans, either invest in it and do necessary rebuild myself with boring by a professional, or break it and make as much as possible on the parts. Realistically - that seems to be the way i'm headded. Thanks for all the advice guys. Tim Quote Share this post Link to post Share on other sites
Critical_Mass 10 Posted June 23, 2011 Sorry for tge bad news mate. hope you can get it sorted by means of a new engine or rebuild. hate to see corrados being broken. but know its not an option for everyone, its a lot of money after all Quote Share this post Link to post Share on other sites
fla 9 Posted June 23, 2011 might be cheaper to get a 2.8 AAA engine and get it rebored to 2.9 and use your existing pistons? Quote Share this post Link to post Share on other sites
TimDoc 0 Posted June 24, 2011 would the pistons and rods all be sound?? Is it just the piston rings that damage the bore?? Tim Quote Share this post Link to post Share on other sites
