IceBlue8 Posted March 21, 2009 Report Share Posted March 21, 2009 Just spent a fortune on my 2002 2.8 A8 QS; service, gearbox oil & filter, new tyres (ouch!), rear spring, brake calitper, CV gaiter.... and now it's developed a misfire! It starts and runs OK from cold but as soon as it starts to warm up (within a mile or so) the misfire starts and the engine management system warning light flashes. Curiously, yesteday, after about 6 miles of gentle driving to get home, it stopped and the light went off. But this morning it's back and sounds pretty bad and runs as rough as hell. Any ideas? And please let it be inexpensive! Link to comment Share on other sites More sharing options...
PsYcHe Posted March 21, 2009 Report Share Posted March 21, 2009 You got VAG-COM? Could be a dodgy coil pack (do they have them on the V6 as well?) or maybe a plug. Link to comment Share on other sites More sharing options...
Ska Posted March 21, 2009 Report Share Posted March 21, 2009 V6's do have a coil packs just in one big cluster at the front of the engine with ignition leads running to the spark plugs. As PsYcHe says VAGcom or VCDS may bring up a code which should be your first point of call for diagnosis. How bad are the symptoms? Is the car bucking/hesitating? If its not missing when cold that may point to a Lamnda sensor which kicks in when warm. But more often than not its proly one of the ignition leads proly on number 3 cylinder or 6 (where the heat builds up). Look at the ends of the ignition leads at the spark plug end to see for any brownish deposites or general wear & tear. Failing that look at the plugs them selves- which ones did you use in your service? And how long after your service did the misfire start? Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 21, 2009 Author Report Share Posted March 21, 2009 Service was a couple of months ago. Don't know what plugs were used, but it was done at A4Audi in Clydebank so should be OK I think. Going for VAGcom on Monday, but I'll check the plug leads after the 6 Nations. Thanks Guys! Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 21, 2009 Author Report Share Posted March 21, 2009 Just checked leads. They all look OK but number 1 was wet, inside and outside the plug connector. Drying out in the sun now. But how did it get wet? Link to comment Share on other sites More sharing options...
Ska Posted March 21, 2009 Report Share Posted March 21, 2009 Wet with Oil? Water? Could mean a new cam cover gasket of its oil; look into the spark plug recess. Spray some WD40 on the wet lead and see if that helps matters. Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 21, 2009 Author Report Share Posted March 21, 2009 How did you get to know all this stuff? I had cam cover gaskets (2?) replaced by A4 Audi and then replaced again just last week because they were leaking still. The 'wet' didn't look oily, but hard to be certain. But I thought the cam cover gaskets were on the right - plug one is on the left - how does oil get there? But you could be on to something. Gaskets were replaced on Wednesday - went to Dundee and back (220 miles) on Thursday - misfire started on Thursday evening on the way to the take away. Does that sound like the problem? And thanks fo taking an interest in this - beers on me next meet! Link to comment Share on other sites More sharing options...
Ska Posted March 21, 2009 Report Share Posted March 21, 2009 Have owned my 2.8 for a few years now and have had the misfire issue too:rolleyes:. Was even quoted for a new gearbox and it turned out to be the ignition lead on no 6 as my dad said! Any way not sure what you mean by gasket being on the right & plug on the left? Here is a pic of my 2.8 (before it was cleaned if any one has a heart attack!), there are two banks (v6) if you like so 2 sets of cam cover gaskets one set to the left of the coil pack cluster and the other to the right. Each set is made up of an outer sealing gasket stopping oil pouring out the side of the engine & the other bit seals the Spark plug recess. There are two 10mm bolts that clamp down a black bracket (for the beauty covers) which also clamp the spark plug recess bit of the gasket; they may have forgoten to tighten them up. With misfires its difficult to diagnose over the internet but getting is VAgcom'ed should help; note that sometimes there may not be a fault code stored in which case I'd defo look at leads, coil pack. Wait until you Vagcom'ed it before you continue. Cleaning up the lead may help look at the metal contacts in the leads are they black? They should be clean & metalic in colour. Hope yo get it sorted soon fella+++ Link to comment Share on other sites More sharing options...
PsYcHe Posted March 21, 2009 Report Share Posted March 21, 2009 Also check that the 'clip' that hold the lead on to the cylinder is tight enough, it may come loose when warmed up, just give it a little squeeze. I'm in the Glasgow area all next week if you want me to whizz my VAG-COM over it, or just pop it in to Andy @ A4 and he'll at least take a look at what it's saying. Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 22, 2009 Author Report Share Posted March 22, 2009 Thanks again guys. Getting it VAGcom'ed locally tomorrow as A4Audi is a bit far when it sounds as bad as it does. The cam cover gasket on the right was the leaking one and, doh, didn't think there would be 2 on a V6 (how dumb is that). But as the cam covers were replaced the day before it started to misfire, it does make me wonder. Going to dry it out, squeeze the clips, spray with WD40 and take her out for a short run to see how it goes. Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 22, 2009 Author Report Share Posted March 22, 2009 This gets odder! Dried it out (I'm pretty sure it was water, not oil) and sprayed everything with WD40. Loads better, but stilla bit of a misfire. VAGcom tomorrow to, hopefully, find out what's up. Link to comment Share on other sites More sharing options...
Ska Posted March 22, 2009 Report Share Posted March 22, 2009 good luck, proly just the dud lead. Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 24, 2009 Author Report Share Posted March 24, 2009 Ever more curious. Nothing on the VAGcom, but loads of water in the chamber around plug number 1. Blown out with compressed air and seems to be running OK again. But where did the water come from????? Link to comment Share on other sites More sharing options...
sloss Posted March 25, 2009 Report Share Posted March 25, 2009 Have you checked for radiator water loss? Does it overheat, even slightly? It's looking like you have a water leak. I don't know that V6 engine at all so it could be a waterpump gasket or at worst a head gasket... Keep us informed. Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 25, 2009 Author Report Share Posted March 25, 2009 No apparent water loss and no overheating. Going in to A4Audi this afternoon for a quick once over. Will post any news on this strange problem tomorrow. Just one thought though - the car did 200 miles without the engine compartment floor in place - possibly water thrown up from the road? Link to comment Share on other sites More sharing options...
Ska Posted March 25, 2009 Report Share Posted March 25, 2009 Highly likely that; I had done the same a while ago and there was water all over the bay. Has it miss fired since you dried it all up? Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 25, 2009 Author Report Share Posted March 25, 2009 When I dried it out a bit myself, it still misfired a bit when it was pulling up hill. But then I had it dried out with an air hose at the local garage and it hasn't misfired since. Took it into A4Audi this afternoon and Andy is baffled! Still a little water down the plug tube, but not much. And nothing on the big facy VAGcom he uses, other than a 'history' record of a misfire. And to add insult to injury, the cam cover gasket is still leaking - which is where I started! Link to comment Share on other sites More sharing options...
Ska Posted March 25, 2009 Report Share Posted March 25, 2009 Can you see any water marks on the cam covers? the nearest water pipe is just to the front of number one leading to the rad. Also check the bulk head seal at the fire wall and the under bonnet sound baffle to see if its wet in the area above number 1. Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 26, 2009 Author Report Share Posted March 26, 2009 Thanks Ska, I'll have a good look over at the weekend Link to comment Share on other sites More sharing options...
harpersimon Posted March 27, 2009 Report Share Posted March 27, 2009 Whose replacing all the Cam covers.. badly!! Surely they shouldn't leak that much when replaced. or so soon anyway. I'd agree with ska, anything 'foreign' down the plug holes tends to make the car run bad - teh plugs overheat. Are they brown where the white ceramic joins the hex/nut part of the plug? good sign they have overheated. I had plug recess's full of oil until replacing the cam cover gaskets - so I know this joy only too well SKA - couldn't resist the old see how clean my covers are shot :-))) Link to comment Share on other sites More sharing options...
IceBlue8 Posted March 31, 2009 Author Report Share Posted March 31, 2009 It's A4Audi replacing the cam cover gaskets. The boys get good press form the A8 folk in Scotland, so I don't think they're screwing up. But no sign of water leaks anywhere. Begining to think there was a 'spill' that worked its wat through to the plug, or an unlucky 'spalsh' whilst the engine floor was missing. Back in agian on Thursday! I could write a book on this saga! And, yeh, I did notice Ska's sparkly cam covers. Hope to see you guys in Lutterworth and buy a few beers in thanks for the help! Link to comment Share on other sites More sharing options...
IceBlue8 Posted April 3, 2009 Author Report Share Posted April 3, 2009 Well, I hope this is a close to this thread. There is no sign anywhere of a water leak, so the key suspects are either a) a spill when it was having the cam covers replaced (but that seems unlikely as I'd done over 200 miles before the misfire started and I would have thought that would have evapourated any water, or b) a very unlucky splash from the road whilst the engine floor was missing. I suppose the latter is possible as the 'beauty covers' aren't a close fit. And as to the cam cover gasket - I'll let you know if it was third tiome lucky after a trip up to Aberdeen next week..... Link to comment Share on other sites More sharing options...
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