Reverend Frog 10 Posted August 21, 2016 My VR6 has been running poorly for ages, so I decided to change the spark plugs today - which did the trick. The worst one was on no. 1 cylinder, and it looked like this (click for bigger image) [ATTACH=CONFIG]84341[/ATTACH] I suspect either worn bore in that cylinder or valve stem seals - what everyone else think? Oil is obviously getting in and fouling the plugs - you can smell burning oil as well. (The car does give a puff of blue smoke when you press the throttle after downhill engine braking) Quote Share this post Link to post Share on other sites
Jim Bowen 1 Posted August 21, 2016 Probably the valve seals Quote Share this post Link to post Share on other sites
Dox 23 Posted August 21, 2016 Isn't number 1 cylinder that suffers with bore wear? Compression test or better still leak down test should reveal worn cylinders. 20+ year old valve stem seals will be rock hard and cracked by now too. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted August 21, 2016 A puff of oil smoke on burn after engine braking does point to bore wear pulling oil past the rings, from what I understand. Quote Share this post Link to post Share on other sites
fendervg 32 Posted August 22, 2016 No.1 will always be somewhat oily on cars this age with a VR engine, unless the head has been rebuilt. Compression test will tell all. Quote Share this post Link to post Share on other sites
Reverend Frog 10 Posted August 22, 2016 (edited) No.1 will always be somewhat oily on cars this age with a VR engine, unless the head has been rebuilt. Compression test will tell all. The head was rebuilt and compression tested before I bought the car, and all was fine at the time, apparently. if a rebore is required, that would involve getting a 2.8 block and getting everything ground out to 2.9, is that right? or would I be better off just getting a new engine? The thing still performs fine, worst case scenario is I just change plugs every so often and keep an eye on the oil level. Edited August 22, 2016 by Reverend Frog Quote Share this post Link to post Share on other sites
fendervg 32 Posted August 22, 2016 You don't even have to change them more often - just clean them occasionally. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted August 22, 2016 Exactly, it'll run for ages like this. Just burns a bit of oil. Quote Share this post Link to post Share on other sites
graham1971 10 Posted April 3, 2017 Just as I thought everything in Corrado world was looking good I've noticed a puff of smoke on startup along with that smell of burning oil. I changed the plugs and leads two weeks ago, do I now need to change my engine too or is this something that can be remedied by a competent VW specialist? Mines only on 119k, seems small mileage compared to lots of others! Quote Share this post Link to post Share on other sites
Dox 23 Posted April 3, 2017 Just as I thought everything in Corrado world was looking good I've noticed a puff of smoke on startup along with that smell of burning oil. I changed the plugs and leads two weeks ago, do I now need to change my engine too or is this something that can be remedied by a competent VW specialist? Mines only on 119k, seems small mileage compared to lots of others! That's typical of worn guides or old hardened stem seals, oil runs down the valve stems and fuel washes it off the valves causing a puff of smoke on start up or when throttling up after decending a steep hill in gear Quote Share this post Link to post Share on other sites
graham1971 10 Posted April 3, 2017 That's typical of worn guides or old hardened stem seals, oil runs down the valve stems and fuel washes it off the valves causing a puff of smoke on start up or when throttling up after decending a steep hill in gear Bottom line, what sort of price would I be looking at to get that done? Just so I have some idea what's normal before my trip to the local tooth suckers for another walletectomy! Quote Share this post Link to post Share on other sites
Jim Bowen 1 Posted April 3, 2017 Think you have to remove the head to change the seals, i was trying to work it out at the weekend. So being a corrado its a good time to do the clutch/chains/tensioners/headgasket/fit a turbo and 6 spd gearbox. Quote Share this post Link to post Share on other sites
graham1971 10 Posted April 3, 2017 Think you have to remove the head to change the seals, i was trying to work it out at the weekend. So being a corrado its a good time to do the clutch/chains/tensioners/headgasket/fit a turbo and 6 spd gearbox. I was thinking more of a walletectomy than going straight to becoming homeless! Quote Share this post Link to post Share on other sites
graham1971 10 Posted April 3, 2017 I've just been reading about some oil additives that can allegedly rejuvenate the rubber seals inside your engine and prevent the above mentioned problem. Has anybody here tried them? Do they work and if so what's the best one? Quote Share this post Link to post Share on other sites
Dox 23 Posted April 3, 2017 I've just been reading about some oil additives that can allegedly rejuvenate the rubber seals inside your engine and prevent the above mentioned problem. Has anybody here tried them? Do they work and if so what's the best one? Not used it, wouldn't bother either, 20 odd years of heat cycles and the seals will be rock hard and cracked by now. The usual method of replacing stem seals is to pass thin rope into the cylinder via the spark plug hole before bringing the piston up to TDC holding the valves against there seats. You then have to fathom a way of compressing the valve springs to remove the collets, caps, springs then remove refit the seal. Quote Share this post Link to post Share on other sites
graham1971 10 Posted April 3, 2017 Not used it, wouldn't bother either, 20 odd years of heat cycles and the seals will be rock hard and cracked by now. The usual method of replacing stem seals is to pass thin rope into the cylinder via the spark plug hole before bringing the piston up to TDC holding the valves against there seats. You then have to fathom a way of compressing the valve springs to remove the collets, caps, springs then remove refit the seal. That's WAY above my pay grade! Sounds as though I'm going to have to bite the bullet, see the local toothsucker and take out another mortgage! Quote Share this post Link to post Share on other sites
Dox 23 Posted April 3, 2017 This type of thing - not watched the whole vid Quote Share this post Link to post Share on other sites
dr_mat 0 Posted April 4, 2017 If only a "small puff of smoke on startup" was the biggest issue on my Corrado repair list. I might choose to live with that until something serious happens! Quote Share this post Link to post Share on other sites
Dox 23 Posted April 4, 2017 That's WAY above my pay grade! Sounds as though I'm going to have to bite the bullet, see the local toothsucker and take out another mortgage! When you say that what's the most complex job you've done so far? There's plenty of help available here if you get stuck and you only need basic hand tools, a bit of rope and a cam locking plate so why not step out of your comfort zone and have a go? http://www.ebay.co.uk/itm/Vr6-Timing-Locking-Plate-Camshaft-Alignment-Tool-/142310560648?hash=item21225ed388:g:n8IAAOSw4CFYvyMz Contains a nice pic of the plate in use Quote Share this post Link to post Share on other sites
graham1971 10 Posted April 4, 2017 When you say that what's the most complex job you've done so far? There's plenty of help available here if you get stuck and you only need basic hand tools, a bit of rope and a cam locking plate so why not step out of your comfort zone and have a go? http://www.ebay.co.uk/itm/Vr6-Timing-Locking-Plate-Camshaft-Alignment-Tool-/142310560648?hash=item21225ed388:g:n8IAAOSw4CFYvyMz Contains a nice pic of the plate in use Most complex job I've tackled by myself to date was dismantling repairing and replacing the now working sunroof! In terms of the oily bits I basically do my own servicing, plugs, leads, filters and fluids etc. At no point yet have I tackled anything like what you've described, I'd be worried about leaving bits in or out and never getting it back on the road again. It's only because of help from the forum members generally that I've been able to do as many of the little jobs I've been able to do myself, the knowledge and attitude of the other members on here is immeasurable. I've spoken to a local VW specialist today who's estimated about £550 in labour and around the same in parts so around £1100 in total. He's said he's done this in the past and said it would be better to replace the chain and tensioners at the same time, as was mentioned by other members, it looks like I'd better start saving! Quote Share this post Link to post Share on other sites
Dox 23 Posted April 4, 2017 Most complex job I've tackled by myself to date was dismantling repairing and replacing the now working sunroof! In terms of the oily bits I basically do my own servicing, plugs, leads, filters and fluids etc. At no point yet have I tackled anything like what you've described, I'd be worried about leaving bits in or out and never getting it back on the road again. It's only because of help from the forum members generally that I've been able to do as many of the little jobs I've been able to do myself, the knowledge and attitude of the other members on here is immeasurable. I've spoken to a local VW specialist today who's estimated about £550 in labour and around the same in parts so around £1100 in total. He's said he's done this in the past and said it would be better to replace the chain and tensioners at the same time, as was mentioned by other members, it looks like I'd better start saving! Ive not done a sunroof, it fills me with dread tbh, I'll cross that bridge one day. You sound more than capable of doing the seals yourself - it may not cure it after all and you may have to go deeper in the engine eventually. There nothing that gives me greater satisfaction than doing a job myself and saving money Good luck with whatever you decide to do Quote Share this post Link to post Share on other sites