rider Posted March 13, 2018 Share Posted March 13, 2018 Just to share some hope for anyone suffering the puff of smoke at startup that invariably points to hardened valve seals needing replacement. My 22 year old Supra was giving out the cloud of smoke on startup if left stood for a period of time spanning more than a few days. I changed the spark plugs a couple of months ago and found the plug on cylinder 6 pooled in about 15ml of oil which I wiped out before withdrawing the plug. The plug had oil seep down the full length of the thread. I'm delighted that since changing the plugs there is no longer any sign of smoke on startup. So my valve seal issue has transpired to be a much simpler valve cover gasket issue. Anyone with the tell tale puff of smoke should whip off the plug cover to see if its just a failed gasket feeding a fair amount of oil into the centre plug area before sending their car off for an expensive stem seal job. I have obtained new valve cover gaskets ready to change those to correct the oil leak, just awaiting replacement coil lead loom clips (Japan 6 weeks order) to replace those that shattered when I unclipped the leads as part of the plug change. I've also bought in some new coil connectors and a set of OE coil packs so will change those out as well while I'm tinkering in that area. Its going to be a Spring/Summer job, when the weather is warmer. I'm certain the car will need the valve seals done one day so I have stockpiled all the OE seals and gaskets ready for that day, but that day isn't going to be in 2018. Its going to get a front suspension and frame overhaul with all new OE parts instead. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 13, 2018 Share Posted March 13, 2018 The oil won't have seeped down the full length of the thread mate, it cant otherwise you'd have combustion gasses coming out the other way The oil would have run down the thread as you pulled the plug out Quote Link to comment Share on other sites More sharing options...
rider Posted March 13, 2018 Author Share Posted March 13, 2018 I wiped out the plug recess thoroughly before removing the plug. Capillary action is a strange phenomena when liquids can flow with or against gravity where pressurised gas pulses will not. Any guide on how to remove a seized plug has spraying with a penetrating oil as the first step. The smoke would only ever occur if it was stood for a good length of time of over a week. All I know now is its been started 4 times in the last 2 months and not a puff, so I'm relieved its a simple fix. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 13, 2018 Share Posted March 13, 2018 I don't believe it personally. Quote Link to comment Share on other sites More sharing options...
Tyson Posted April 14, 2018 Share Posted April 14, 2018 I don't believe it personally. Interesting, still no smoke ? Quote Link to comment Share on other sites More sharing options...
blythmrk Posted April 14, 2018 Share Posted April 14, 2018 Interesting! I know the car should stand over night but should we be letting the car stand for a few days then starting up to check for blue smoke on start up for the valve stem seals? Although it’s a when not if job also could somebody post up a link on the rope and airline method to do this? Quote Link to comment Share on other sites More sharing options...
rider Posted April 14, 2018 Author Share Posted April 14, 2018 (edited) I only occasionally got a puff of smoke if the car is stood for a long time, 1 week +. Since wiping out the oil pool from the spark plug well no smoke. I've been persuaded by my mechanic matey that I may as well just change the stem seals seeing I'm taking the covers off and that's half way there so he is going to give me a hand with the job. I've bought in a compression tester that I can use the hose from to do the airline method which is supposed to be a lot quicker than stuffing the cylinder with rope. I'll near TDC each cylinder just in case refitting the spring collets breaks the pressure seal on the valve seat. Reading around various forums you have guide pressures of 20psi to 100psi so I'll start off at a regulated 50psi and see how it goes from there. My bits of kit, the collet collector and air line are coming from the USA. Typically, what costs $35 over there costs £65 here. They should be here in a week or so so I'm panning on tackling the job right after the end of month MOT. If you have time, feel free to come by and observe. I'd hope we could manage it all over a normal day or two short days. I'll be changing the 4 remaining original coil clips for new ones at the same time and all of the valve cover hoses as well. The very detailed guide that I'll be following is here. . Though you do need to add in having the cylinder bunged with rope or pressurised. And while you are at it, you may as well . If you do the work you'll probably find the loom number 7 clips disintegrate, these carry the loom to the coil clip attached onto onto the coil plate. I bought a set in from Japan that took 10 weeks to arrive. You can use generic clips but if you need one or two OE clips I bought in a few spares as the same clips are also used in the wider engine bay as loom clips. Edited April 14, 2018 by rider (see edit history) Quote Link to comment Share on other sites More sharing options...
Dnk Posted April 14, 2018 Share Posted April 14, 2018 Taking the covers off isn't half way there trust me Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted April 14, 2018 Share Posted April 14, 2018 It was never, ever, 110% going to be capillary action drawing oil into the chamber. Any technically minded person would poo poo that straight away Quote Link to comment Share on other sites More sharing options...
rider Posted April 15, 2018 Author Share Posted April 15, 2018 It was never, ever, 110% going to be capillary action drawing oil into the chamber. Any technically minded person would poo poo that straight away I hope you have never waste time and money applying penetrating fluids as they would never work, requiring capillary action to be drawn into torqued threads. In the same way as boundary lubrication is also impossible because that, similar to capillary action, requires an affinity between the liquid (through polarity or chemical interaction) and in the case of cars metal surfaces that is greater than the interaction within the liquid. I'm not about to throw my post grad qualification in a highly technical subject away simply because I just don't see the poo. Quote Link to comment Share on other sites More sharing options...
rider Posted April 15, 2018 Author Share Posted April 15, 2018 Taking the covers off isn't half way there trust me Noted, I'll leave the cans of beer stowed in favour of flasks of tea while we are doing the seal changes. If it does take a bit longer than hoped for its no real problem as the car is not a daily driver so I could do it over several weekends if needed. Quote Link to comment Share on other sites More sharing options...
Dnk Posted April 15, 2018 Share Posted April 15, 2018 Noted, I'll leave the cans of beer stowed in favour of flasks of tea while we are doing the seal changes. If it does take a bit longer than hoped for its no real problem as the car is not a daily driver so I could do it over several weekends if needed. You'll be doing well if you get the job done from start to finish in under 8 hrs Quote Link to comment Share on other sites More sharing options...
supraGZaerotop Posted April 15, 2018 Share Posted April 15, 2018 I hardly use my supra at the moment,. Parked up for weeks on end. Took it out yesterday roof off nice day. Smoked like a tropper on start up. Clears in seconds. It's just that first fire up after been parked up. If i use the car often ie every week it don't do it at all. They are old cars now in they are Bound to puff a bit, don't bother me Quote Link to comment Share on other sites More sharing options...
rider Posted April 15, 2018 Author Share Posted April 15, 2018 They are old cars now in they are Bound to puff a bit, don't bother me If it was only a puff of smoke after weeks of standing it likely wouldn't bother me but, a leaking valve cover gasket deep pooling oil into the number 6 spark plug recess does. Having a mechanic matey offering up free time to assist in changing out the stem seals (which really means I'll be assisting him) is an offer I find very difficult to resit. If it was just me, doubtless I'd replace the cover gasket and be more than happy to stop there. Quote Link to comment Share on other sites More sharing options...
Dnk Posted April 16, 2018 Share Posted April 16, 2018 I hardly use my supra at the moment,. Parked up for weeks on end. Took it out yesterday roof off nice day. Smoked like a tropper on start up. Clears in seconds. It's just that first fire up after been parked up. If i use the car often ie every week it don't do it at all. They are old cars now in they are Bound to puff a bit, don't bother me If it smokes like that your seals are shot, they will be letting oil past all the time you just dont notice it when your driving Quote Link to comment Share on other sites More sharing options...
Ric Posted April 16, 2018 Share Posted April 16, 2018 I followed this thread on my first supra - http://www.mkivsupra.net/vbb/showthread.php?49859-How-To-Valve-Stem-Seal-Replacement Im pretty much a novice at mechanical stuff but i found it quite simple, took my time over 2 days or so. Quote Link to comment Share on other sites More sharing options...
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