ksbkrew Posted August 12, 2010 Share Posted August 12, 2010 hello one year ago, my supra's engine has broken, i 'd never open the block to check why because somebody buy the car to me with the engine broken. Today, i'm asking myself why had I this problem. In fact, my engine's running good just before i take the compression i do like this: - remove coil packs -remove all the spark plugs -remove the ecu and start with foot on the accel pedal with the apparel on each plug hole after that, i put back all this stuff and when i start the car again, clac-clac-clac I see two possibilities -something fall into the spark plug hole but there were no tool missing or anything else (but maybe something that was against the spark plug that i don't see) -the ecu removal is an error from me and it would be better to remove only the injector fuse? sorry for my english i'm french and i'm a little confused to ask this to you as i certainly made a beginner mistake but i need to find why to prevent made it again. Thanks for all Tom Quote Link to comment Share on other sites More sharing options...
nevins Posted August 12, 2010 Share Posted August 12, 2010 sounds like a nut or something got into the cylinder mate. Quote Link to comment Share on other sites More sharing options...
Dnk Posted August 12, 2010 Share Posted August 12, 2010 (edited) Check the valve in the compression tester hasn't come out and fallen into a cylinder ! Get a Boroscope and have a look Edited August 12, 2010 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
TLicense Posted August 12, 2010 Share Posted August 12, 2010 I think he's saying he hasn't got the car anymore, but was wondering if he did anything wrong so he doesn't make the same mistake in the future. Quote Link to comment Share on other sites More sharing options...
TLicense Posted August 12, 2010 Share Posted August 12, 2010 I see two possibilities -something fall into the spark plug hole but there were no tool missing or anything else (but maybe something that was against the spark plug that i don't see) -the ecu removal is an error from me and it would be better to remove only the injector fuse? Hi Tom, Something could well have fallen in. The area where the sparkplugs are can collect a lot of debris. The ecu removal shouldn't have made a difference. Quote Link to comment Share on other sites More sharing options...
David Reid Posted August 12, 2010 Share Posted August 12, 2010 I think something fell in or you missed tightening one spark plug leaving no compression on one cylinder. Quote Link to comment Share on other sites More sharing options...
absz Posted August 12, 2010 Share Posted August 12, 2010 sounds like a flat battery to me Quote Link to comment Share on other sites More sharing options...
Terminator Posted August 12, 2010 Share Posted August 12, 2010 Hi Tom, Your English is much better than many on the forum. Was the engine turning over when you tried to start it? Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 12, 2010 Author Share Posted August 12, 2010 Check the valve in the compression tester hasn't come out and fallen into a cylinder ! Get a Boroscope and have a look we 'd checked this and the tester is still ok and working perfect today Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 12, 2010 Author Share Posted August 12, 2010 I think something fell in or you missed tightening one spark plug leaving no compression on one cylinder. missed tightening one spark plug ? you mean that i made an error when i 'd changed a spark plug before and tightened to loose it? One thing that happens during the compression test is that the tester jumps off the hole because i think i won't have tighten it as it has to. could it cause the broke? Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 12, 2010 Author Share Posted August 12, 2010 Hi Tom, Your English is much better than many on the forum. Was the engine turning over when you tried to start it? thanks for my english , i try to do my best. what du you mean by turning over? thanks for all your help Quote Link to comment Share on other sites More sharing options...
Supranature Posted August 12, 2010 Share Posted August 12, 2010 thanks for my english , i try to do my best. what du you mean by turning over? thanks for all your help Il y a un malentendu avec votre description de la fracas quand vous avez tante de retourner l'engine. L'arbre de manivelle, tournait-il? Excusez mon francais;) Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 12, 2010 Author Share Posted August 12, 2010 ok i think i understand when i do the compression test, i heard that the crank turns, because on the cylinder 1-2-3-4 i've got a score of 10 i compression and the last two cylinders give me a score of 8 and 4 after have done it, i put back the coilpacks, plugs, and ecu , started the car, the engine runs for 5 seconds and after knocks a lot Quote Link to comment Share on other sites More sharing options...
TLicense Posted August 12, 2010 Share Posted August 12, 2010 What units are you using for your compression? Bar, PSI or Kpa? It should be around 170 PSI. It almost sounds like the timing is out, but nothing you've written here would cause that. Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 12, 2010 Author Share Posted August 12, 2010 the unit are in Bar, the timing out? with the timing belt? after i broke, i think about this and all was ok, at cams and at crank, all was lined up, and the timing belt wasn't broken (was nearly new) Quote Link to comment Share on other sites More sharing options...
TLicense Posted August 12, 2010 Share Posted August 12, 2010 If it was 10, 8 and 4 bar, all of those are very low, and indicate that there was a problem before you started. Are you sure the gauge was fully sealed into the spark plug hole? Why did you decide to do a compression test in the first place? Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 13, 2010 Author Share Posted August 13, 2010 my 4 first cylinders were similar in pressure, and only the two last were fallin down. i think the gauge was perfect because, it is screwed in the place of the spark plug. i decided to do a compression test because i'd want to go to a single, in fact my car was turning well before taking compression (twins stock, bpu+ a 1.3b and i was in front of 997 carrera 4s, maserati 3200gt, m3 e46, golf 2 vr6 T, ...) so i don't really understand the value of pressure in the engine. But when i get the spark plug off the engine, my last one get a lot of oil in it which means i think that my pistons seal aren't good which can be an explanation for the loss of compression, no? Quote Link to comment Share on other sites More sharing options...
David Reid Posted August 13, 2010 Share Posted August 13, 2010 I think you may have connected the coils for cylinder 5 and 6 the wrong way arround, the spark being 180 degree out will then couse it to knock. Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 13, 2010 Author Share Posted August 13, 2010 i don't think because i drive the car about one year, i made a lot of care at every spark plug change, and the car drives every day without problem Quote Link to comment Share on other sites More sharing options...
TLicense Posted August 13, 2010 Share Posted August 13, 2010 If you're sure the connectors were plugged in correctly, it may have been that one or more of the connectors were worn, so it could have just been running on 5 or fewer cylinders. Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 13, 2010 Author Share Posted August 13, 2010 and the engine could have broke suddenly like that? or it's the compression test that kills it? and it's strange because the car wasn't runnig like on 5 cylinders Quote Link to comment Share on other sites More sharing options...
Pig Posted August 13, 2010 Share Posted August 13, 2010 The 2 members above are saying that your engine may not be broken. If your coil packs that plug onto your spark plugs are on the wrong way round it may cause the noise you are experiencing. J'ai terrible francais Quote Link to comment Share on other sites More sharing options...
ksbkrew Posted August 13, 2010 Author Share Posted August 13, 2010 ok! i don't understand the meaning! but for me it was really broken , it made big CLAC, like a conrod, it accelerates with the rpm Quote Link to comment Share on other sites More sharing options...
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