Havard Posted May 30, 2009 Share Posted May 30, 2009 Looks like I have found the source of my misfire..!! Took everything to bits this afternoon and found a large amount of oil on two of my plugs. The car hasn't been smoking or using a lot of oil but it looks like the thought of a TT conversion is now a reality as my hand is forced. It also looks like the Supra - Le Mans trip is dead for me. It's a Mazda 6 Sport instead..!! To say that I am upset is a slight understatement. Unless someone tells me it's not a lost cause?? H. Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted May 30, 2009 Share Posted May 30, 2009 i have seen oil residue in spark plugs before - stuck new ones in and when checked 100 miles later nothing there.. Quote Link to comment Share on other sites More sharing options...
Todd Posted May 30, 2009 Share Posted May 30, 2009 Leaky rocker cover? Not sure if this is an issue on the Supras but I've seen the same issue on MR2s and MX5s, both cured by a new rocker cover. Hope it's as cheap a fix as that for you mate Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted May 30, 2009 Share Posted May 30, 2009 (edited) Might be rings, have you had a compression test done? Edited May 30, 2009 by Swampy442 (see edit history) Quote Link to comment Share on other sites More sharing options...
JustGav Posted May 30, 2009 Share Posted May 30, 2009 Was there any oil on the cermaics of the plug, I know my rocker gaskets went a while back resulting in oil down the plug bores, in much the same way the water would go when jetwashing the engine bay. Quote Link to comment Share on other sites More sharing options...
dan4 Posted May 30, 2009 Share Posted May 30, 2009 Leaky rocker cover? +1 I doubt there would be a large amount of oil on a plug electrode, it wouldnt stay there under combustion;) Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted May 30, 2009 Share Posted May 30, 2009 Yup, if the oil is on the lead side of the plug then its defo rocker gaskets. Quote Link to comment Share on other sites More sharing options...
Havard Posted May 30, 2009 Author Share Posted May 30, 2009 The oil is on the plug side (mainly). There was a tiny amount sat in the plug well on cylinder 4. I am going to have to get my hands on a compression tester and see if it's that. On the plug in cylinder 3 (3rd on e from the front of the car) there was no oil in the plug hole but there was a fair bit on the spark end. I was going to put it all back together and see if ran any better now I have cleaned all the plugs. I paid £107.00 for a set of new plug leads this morning and I don't want to use them if the engine is FUBAR but it may still be a problem with the original leads...?? There was a lot of oil on one of the plugs especially!! I think from where I am now, compression test, then replace leads and plugs and see that happens from there. The TT conversion is always an option or Mrs H and I have considered breaking the car for parts and starting a fresh?? H. Quote Link to comment Share on other sites More sharing options...
hadyn Posted May 30, 2009 Share Posted May 30, 2009 Leaky rocker cover gasket is a common 'problem' on older Supras... Quote Link to comment Share on other sites More sharing options...
Mrs H Posted May 31, 2009 Share Posted May 31, 2009 Good News! Compression test passed that engine is sweet as a nut, to quote the mechanic :D:D:D Vicki x Quote Link to comment Share on other sites More sharing options...
Todd Posted May 31, 2009 Share Posted May 31, 2009 woo hoo, take it that it isn't misfiring anymore? Quote Link to comment Share on other sites More sharing options...
Havard Posted May 31, 2009 Author Share Posted May 31, 2009 woo hoo, take it that it isn't misfiring anymore? We have had it out for a 60 mile run or so and no misfire yet. All the original parts are there so I will be surprised if it doesn't return. It looks like the oil was actually of the outside of the plug and it's covered the spark end when I have removed it. It is now looking like a leaky rocker cover but I don't know how long it is taking before it affects the spark plug. Will it get me to Le Mans and back?? That's anyones guess.... I am still a bit concerned that it's using a lot of fuel but I have been driving it hard trying to get it to play up again. Does anyone have any pictures of new v's used 02 sensors. I think I will invest in some new ones this week or perhaps just do the lemon juice thing. If the 02 sensors are Fubar, do they show up as a fault code?? H. Quote Link to comment Share on other sites More sharing options...
Scooter Posted May 31, 2009 Share Posted May 31, 2009 It is now looking like a leaky rocker cover but I don't know how long it is taking before it affects the spark plug. if you haven't done so already it is worth nipping up all the 10mm(?) bolts on the cam covers go steady mind as they only need a light torquing...... Quote Link to comment Share on other sites More sharing options...
Havard Posted May 31, 2009 Author Share Posted May 31, 2009 if you haven't done so already it is worth nipping up all the 10mm(?) bolts on the cam covers go steady mind as they only need a light torquing...... I actually haven't done that yet. Good shout..!! H. Quote Link to comment Share on other sites More sharing options...
Kirk Posted May 31, 2009 Share Posted May 31, 2009 might be worth while takin off the rocker covers, cleaning it all up then putting them back on Quote Link to comment Share on other sites More sharing options...
DaveR Posted May 31, 2009 Share Posted May 31, 2009 I had this on cylinders 5 and 6 a while back. I worried quite a lot when I looked it up online (the double-edged sword of the interpipe!), but it turned out to be just the cam cover seals. About £20 on parts and a bit of labour and all was well in the world again! Quote Link to comment Share on other sites More sharing options...
Kirk Posted May 31, 2009 Share Posted May 31, 2009 forget labour! cheaper doing it yourself... isnt exactly rocket science is it. Take two covers off, clean up, put new seals on, covers back on and away the lads! Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted May 31, 2009 Share Posted May 31, 2009 just make sure you dont over tighten them Glad to see its running ok again Paul Quote Link to comment Share on other sites More sharing options...
Havard Posted June 1, 2009 Author Share Posted June 1, 2009 forget labour! cheaper doing it yourself... isnt exactly rocket science is it. Take two covers off, clean up, put new seals on, covers back on and away the lads! I'll have a look at this after the Le Mans trip. I am thinking of just fitting the new plug leads now as I am not convinced that the oil was the source of the problem. There was only a couple of mm in the plug recess so I would be surprised if this was affecting the plugs..!! H. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 1, 2009 Share Posted June 1, 2009 Dont forget the rubber seals that go on the bolts, the seal is built into the washer and will also need changing, youll find the cam cover seals will have gone very brittle and hard so tightening them down will only be a short term fix if any at all. Just done mine and took a couple of hrs with the hardest part being getting the cam covers free, youll need a rubber mallet and some gentle encouragement if there stuck on like mine were. Quote Link to comment Share on other sites More sharing options...
Havard Posted June 1, 2009 Author Share Posted June 1, 2009 Dont forget the rubber seals that go on the bolts, the seal is built into the washer and will also need changing, youll find the cam cover seals will have gone very brittle and hard so tightening them down will only be a short term fix if any at all. Just done mine and took a couple of hrs with the hardest part being getting the cam covers free, youll need a rubber mallet and some gentle encouragement if there stuck on like mine were. Thanks Dunk, I'll leave this till I get back from Le Mans. The car is going to road tested every night this week (50 mile or so) in order to see if the problem returns. One night this week I'll fit the new leads and hope for the best. It's either the rocker cover or the old leads breaking down, as long as I keep an eye on it then we should be ok..!! H. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 1, 2009 Share Posted June 1, 2009 Thanks Dunk, I'll leave this till I get back from Le Mans. The car is going to road tested every night this week (50 mile or so) in order to see if the problem returns. One night this week I'll fit the new leads and hope for the best. It's either the rocker cover or the old leads breaking down, as long as I keep an eye on it then we should be ok..!! H. Have a nice trip and fingers crossed you have a trouble free run to Le Mans and back Dont forget to check your oil level before you go, mine didnt leak down to the plugs but to the back of the block and it was losing quite a bit. Quote Link to comment Share on other sites More sharing options...
DannoSupra Posted June 1, 2009 Share Posted June 1, 2009 Happy Days buddy! Sorry i couldn't come down yesterday, but glad you got it sorted! Could you possibly make a road test trip down here and have a Pancake? Quote Link to comment Share on other sites More sharing options...
Havard Posted June 1, 2009 Author Share Posted June 1, 2009 Have a nice trip and fingers crossed you have a trouble free run to Le Mans and back Dont forget to check your oil level before you go, mine didnt leak down to the plugs but to the back of the block and it was losing quite a bit. The oil seems fine. I'm going to strip it all down one night this week again and see if there is any oil in the plug recesses. Fingers crossed..!! Could you possibly make a road test trip down here and have a Pancake? Next weekend may be a possibility. It's having a full run every night this week but I will give it a proper 200 miler at the weekend. It's going to do 1200 miles during the Le Mans trip so I'm going to be worried all the time no matter what happens this week..!! Could be worse I suppose..!! H. Quote Link to comment Share on other sites More sharing options...
Todd Posted June 1, 2009 Share Posted June 1, 2009 It's going to do 1200 miles during the Le Mans trip so I'm going to be worried all the time no matter what happens this week..!! Could be worse I suppose..!! H. My, aren't we the cheerie chappy these days Quote Link to comment Share on other sites More sharing options...
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