hodge Posted January 9, 2007 Share Posted January 9, 2007 What can cause this. The car is at envy at the min and hes in the process of taking the head off. Just after a bit of pre warning what to expect. The car is flooding with petrol when its turned over. A bit of a list of possablities if you dont mind my fellow enthusiasts. Quote Link to comment Share on other sites More sharing options...
Ric Posted January 9, 2007 Share Posted January 9, 2007 if theres no compression this is headgasket failure or cracked block, perhaps a bent valve or somthing? Quote Link to comment Share on other sites More sharing options...
tDR Posted January 9, 2007 Share Posted January 9, 2007 Dropped a valve likely if zero compression. Exhaust valves usually more common than inlet. Hopefully not a cracked block anyways, that's very uncommon on the 2JZ as is headgasket failure since it's the MLS type as standard. 3S-GTE's in ST205 Celicas on the other hand like to crack the block the moment you start running over 400bhp in anger Quote Link to comment Share on other sites More sharing options...
hodge Posted January 9, 2007 Author Share Posted January 9, 2007 Robert at Envy seems to think that the head gasket could be gone, I suppose thats gona be the cheapest option. I cant see the bolck being cracked at all, supra engines are ment to be dullet proof so I heard, but then again it would be just my luck. I had to have 2 engine rebuilds on my Impreza. Quote Link to comment Share on other sites More sharing options...
tDR Posted January 9, 2007 Share Posted January 9, 2007 Well, they don't have to take the head off to further diagnose - they could do a leakdown test. Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted January 9, 2007 Share Posted January 9, 2007 If there's no compression on 2 adjacent cylinders its almost certainly the headgasket blown between them. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted January 9, 2007 Share Posted January 9, 2007 Well, they don't have to take the head off to further diagnose - they could do a leakdown test Brian. No point really, its going to be the headgasket. They may as well use their time constructively rather than trying to diagnose the obvious Quote Link to comment Share on other sites More sharing options...
Jake Posted January 9, 2007 Share Posted January 9, 2007 Wouldn't you usually still get some compression with a BHG? My money's on holed piston or dropped valve. Hope I'm wrong though. Good luck Hodgster Quote Link to comment Share on other sites More sharing options...
tDR Posted January 9, 2007 Share Posted January 9, 2007 If there's no compression on 2 adjacent cylinders its almost certainly the headgasket blown between them. Surely between them would mean the compression has to go somewhere? Any hydrocarbons in the coolant? - do a sniffer test on the rad. Any water in the oil? - mayo like crap under the oil filler cap is a giveaway. The best diagnosis is a leakdown test though. Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
tDR Posted January 9, 2007 Share Posted January 9, 2007 No point really, its going to be the headgasket. They may as well use their time constructively rather than trying to diagnose the obvious Totally disagree - I agree with Jake I'd expect at least some compression. Quote Link to comment Share on other sites More sharing options...
Feakins Posted January 9, 2007 Share Posted January 9, 2007 If there's no compression on 2 adjacent cylinders its almost certainly the headgasket blown between them. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted January 9, 2007 Share Posted January 9, 2007 Surely between them would mean the compression has to go somewhere? Brian. Yeah, well it does, through the hole in the gasket, into the adjacent cylinder, and out the exhaust or inlet manifold depending on what stroke the adjacent cylinder is on. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted January 9, 2007 Share Posted January 9, 2007 Wouldn't you usually still get some compression with a BHG? My money's on holed piston or dropped valve. But a holed piston or a dropped valve would only give a loss of compression on one cylinder. To get it on 2 cylinders you're talking 2 holed pistons or dropped valves. For them both to occur at the same time, you'd certainly know you'd done some damage Couple that with it being on adjacent cylinders and a BHG between the two is by far your best bet. I've been wrong (occasionally ) in the past, but I'd be very surprised if I was this time. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted January 9, 2007 Share Posted January 9, 2007 Totally disagree - I agree with Jake I'd expect at least some compression. Why? If there's a leak into the next cylinder, all the charge is going to go that way and out through the appropriate manifold. Quote Link to comment Share on other sites More sharing options...
Andy Supra Posted January 9, 2007 Share Posted January 9, 2007 Hodge i'm not clue'd up but hopefully seeing as Xmas just went it won't be to expensive. All I can say is it's the most ideal time of year for the news though least weather is crap so your not missing much driving it out and about. Quote Link to comment Share on other sites More sharing options...
tDR Posted January 9, 2007 Share Posted January 9, 2007 Why? If there's a leak into the next cylinder, all the charge is going to go that way and out through the appropriate manifold. If you're doing a compression test you crank it over at least 4 times on one turn of the key with the throttle at WOT. This would allow for valves being open depending what part of what stroke they're on..... to repeat I'd still expect some compression if it's just the headgasket. I'd say zero compression on these two cylinders - high EGT's resulting in damaged valves, purely on the face of the information we have. What's the background hodge? How was the car running? Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
geoffvalenti Posted January 9, 2007 Share Posted January 9, 2007 If you're doing a compression test you crank it over at least 4 times on one turn of the key with the throttle at WOT. This would allow for valves being open depending what part of what stroke they're on..... to repeat I'd still expect some compression if it's just the headgasket. Brian. OK, I'm not going to continue this "yes it will, no it won't" discussion any more, its all theoretical and I'm not going to argue for the sake of it and risk becoming bad friends over it. Hodge, just let us know what the outcome is when they take the head off. If I'm right, I won't crow, and if I'm wrong, I'll admit it Quote Link to comment Share on other sites More sharing options...
tDR Posted January 9, 2007 Share Posted January 9, 2007 Hey, wouldn't bother me if you're right Geoff - I'd just wanna know why / how - I don't profess to knowing everything and enjoy learning what I've not already learned! Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
Gordon F Posted January 9, 2007 Share Posted January 9, 2007 If there's no compression on 2 adjacent cylinders its almost certainly the headgasket blown between them. Totally correct. There may be a cracked head or block but HG is the obvious candidate. Hey, wouldn't bother me if you're right Geoff - I'd just wanna know why / how - I don't profess to knowing everything and enjoy learning what I've not already learned! Instead of being compressed, the charge will leak through the HG to the next cylinder which will be on a different stroke. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 9, 2007 Share Posted January 9, 2007 What can cause this. The car is at envy at the min and hes in the process of taking the head off. Just after a bit of pre warning what to expect. The car is flooding with petrol when its turned over. A bit of a list of possablities if you dont mind my fellow enthusiasts. See this thread, I guess you could be looking at something similar. Was the engine modded? Single turbo? http://www.mkivsupra.net/vbb/showthread.php?t=95333 Quote Link to comment Share on other sites More sharing options...
hodge Posted January 10, 2007 Author Share Posted January 10, 2007 Standard engine, FMIC, induction kit, boost controller FCD, apart from that there good old Toyota parts. The car was parked outside of work all night when I stared it it was really spluttery until I gave it a good rev and then it was fine. It did the same for the next few days butonly when cold. Then 1 day it just wouldnt start. It turns over but wont fire just floods pots 5 and 6. That about I can tell you folks. I hope it just is the Head Gasket otherwise im looking at some but money. Its just something else for the wife to moan about. Quote Link to comment Share on other sites More sharing options...
Guest Garfy Posted January 11, 2007 Share Posted January 11, 2007 I hope it just is the Head Gasket otherwise im looking at some but money. Its just something else for the wife to moan about. Don't sell your but dude, the Supra's a cool car but nothing is worth that :rlol: Quote Link to comment Share on other sites More sharing options...
hodge Posted January 11, 2007 Author Share Posted January 11, 2007 OK folks HERES THE UPDATE....................... Been up to Envy today and theyve got the head off. 5 of the valves were stuck open and some of the others were closing to slowly. Hence why it wont start. Ive been lucky I think, no bent valves nothing cracked or broken. ive brought the head home and will take it to work net week to strip it down and clean it all up. While im on im gona do the oil seals and was also thinking of porting it a little. Any surggestions on any other thinks that need to be done whilst ive got the head off. Quote Link to comment Share on other sites More sharing options...
JustGav Posted January 11, 2007 Share Posted January 11, 2007 Check the valves very carefully... Personally if it was me and you were going to rebuild the head from scratch, I would replace the valves and grind them in. Quote Link to comment Share on other sites More sharing options...
imi Posted January 11, 2007 Share Posted January 11, 2007 so why did that happen? Quote Link to comment Share on other sites More sharing options...
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