Guest bastaad525 Posted February 28, 2004 Share Posted February 28, 2004 Well I hope that this post doesn't get deleted by some server mishaps!! A friend came over and helped me pull the head off today. The head seems fine, though of course I'll be taking it to a machine shop to check for level-ness and such. The oil had turned very milky... this must have happened from the two times I started the car after I got it home after the gasket blew, as when I checked it after first towing it home the oil looked fine. Anyways... as far as I can see, the cam lobes and rocker wipe surfaces dont look like they've been hurt by the watery oil... HOPING that being synthetic, it was able to still protect the motor somewhat. Well, it definately appears to be the gasket that went out, and in a BIG way. The head has no visible cracks. But... the gasket was TORE UP. Okay, this was a felpro headgasket... for those who aren't familiar with them (I have only used them so I dont know if this applies to other brand gaskets) they have metal rings built in around the cylinder bore hole. Well... the ring around the #5 hole was chewed up really bad. A big piece of it, about one third of it was missing!!! Just broken off. And the ends where it had broke were sticking inward, both about a 1/2", they would have been exposed inside of the cylinder/chamer. The one-third piece was simply gone... I found no debris, no trace of it, and LUCKILY there does not appear to be any damage to either the chamber, piston crown, or cylinder wall in that cylinder, from debris getting tossed around. It begs the question though of where exactly did that piece go?! We're talking a section of 'ring' about 3" long... I guess it just melted up or broke up and went out the exhaust? I never heard anything from the motor, any kind of weird noises... car ran great up until that day the gasket blew and coolant was coming from the exhaust. Also, the gaskets metal rings on three of the other cylinders looked like they had been clamped down on around the edges... like... squeezed or hit. My best guess is that somehow the gasket was not lined up properly, and the pistons were striking the edges of the gasket rings. Again... no signs of damage on any of the piston crowns. Really odd... so I guess the gasket wasn't lined up right, but how?? Kinda hard not to line it up properly. And there was a pretty noticeable chunk of the soft gasket material missing between the cyl #5 ring and and nearby water port, so that's where the coolant was coming from. The #5 plug also was the only one with any sign of coolant on it. Not sure how coolant was getting outside of the engine though. I'm really amazed that whole cylinder isn't screwed... anyways... I'll be going with a stock nissan gasket and new turbo head bolts... decided (with some help from you guys) that I really dont need to spend the money on a metal gasket. After seeing this I'm willing to bet that I was right after all, that there WAS no detonation, as I never heard the slightest ping... I'm thinking that gasket was just lined up badly, and the piston kept hitting the edge of that ring (come to think of it... this might account for the mysterious 'valve tap' noise that just would not go away no matter how much I adjusted the valves!!) until finally the ring broke... then it was just a matter of time before the softer gasket material gave way to the cylinder pressures and finally blew out. Though, with those broken ends exposed in the chamber, there may have still been some ping, as I can only assume those things ended up glowing red hot, enough to ignite the fuel... I dunno... Man... when it rains it pours... but I guess I'm lucky. Assuming the head and deck surface are okay, all the cylinders look great, pistons look fine, came lobes and rockers look fine... and since the motor never overheated (at least the guage never read high when this happened, and there was still plenty of coolant in the system) I hope the head wont need to be surfaced, or the block... just a new gasket put it all back together change out the oil (fourth time in two months... and synthetic at that!!! I need to buy stock in Mobil 1!!!) and I should be fine. Quote Link to comment Share on other sites More sharing options...
Jersey Posted February 28, 2004 Share Posted February 28, 2004 Glad to hear it's all working out for ya 525 and you decided to battle it. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted February 28, 2004 Share Posted February 28, 2004 told ya you should keep it! im glad ur getting it all worked out. you have a very sweet Z and be happy about that. just get that intercooler on there!! mike Quote Link to comment Share on other sites More sharing options...
EvilRufusKay Posted February 28, 2004 Share Posted February 28, 2004 Very Cool!! After all the speculation and conversation all it need was a little love from a good wench...I mean wrench!!! Glad to hear it was not bad. Does your block still have the dowels used to line up the head? If so it would be REALLY hard to not put the gasket on straight as it usually slides over the same dowels for alignment as well. Hmmm..... Quote Link to comment Share on other sites More sharing options...
yo2001 Posted February 28, 2004 Share Posted February 28, 2004 metal ring=melted and done See, #5 runs leaner than others. 8) That's where I broke two of my HG. I don't know the exact reasons but I think it's because #5 is right above where the turbo is mounted and because #5 got best exhaust flow (visually, I never tested it) which makes it flow more air??? Good luck man Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 28, 2004 Share Posted February 28, 2004 One of the dowels is missing, and I think that may be the problem right there. Still hard to mis-align the gasket though with the twelve head bolts going thru it, wouldn't it be?? I wish the guy who installed the head last time had informed me one of those dowels was missing Yeah well I'm glad it's as 'minor' as it is... now just worried about side effects... the level of water in the oil really scaring me. I'm also kinda glad that it was something like this... at least now I can be relatively sure it had nothing to do with the way I was driving the car... it was probably just a matter of time. And probably also had nothing to do with the car running too lean or anything like that. Not that I still wont invest in a FPR to up fuel pressure a bit and richen up the top end, but... well it's just nice to not have to keep kicking myself thinking I was playing russian roulette with my car and lost. Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted February 28, 2004 Share Posted February 28, 2004 kewl - a relatively simple fix. Glad you decided to keep it... Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted February 29, 2004 Share Posted February 29, 2004 If I was in the mindset not to pull the bottom end apart (which I think I would do if there was a grey milky oil...) then atleast run a few oil changes of regular oil and change the filter a few times before doing the mobil one. Remember that water got into the turbo, bearing journals, oil pump, everywhere... Anyone familiar with the "engine flush" additatives? Maybe that would be an option as well. You really want to get all the water out, but that is not possible unless you take it apart, so atleast get as much as you can... Glad to hear you are keeping it though. All the crap you have gone through is a learning curve and you are now ahead of the game so to speak... Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 29, 2004 Share Posted February 29, 2004 ugh... pulling the bottom apart is not really an option for me. Good idea though to just run regular oil first to kinda flush out as much water as I can and then switch over. Okay so after I get the head back on and put new oil in there, how long should I drive it before changing the oil again? A few minutes? A few miles? A few days? Also, isnt what's left of the water going to burn off? I mean, you get condensation in there every day, and it burns off as the motor warms up... but now that the water is kinda 'mixed in' with the oil, can it still burn off like that? I think the only 'engine flush' type of additive I would even trust would be Marvel Mystery Oil... you guys think I should throw in a bottle of that with some regular oil to flush out the water before going back to synthetic? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 29, 2004 Share Posted February 29, 2004 yo2001 - yeah but I'm thinking the damaged gasket ring had nothing to do with running lean. Because there is damage on three of the other rings too, like they weren't lined up right and were getting hit by the pistons. They look like they've been crushed down... there is a very visible groove in them. I gotta get some pictures taken so you guys can see what I'm talking about. The number five was probably sticking into the cylinder the most and so instead of just getting a little groove it probably got hit enough to where it just got snapped off. Again though, to be safe, I will be getting an FPR and turning up the fuel pressure to make SURE that the fuel mixture is not an issue. I'm going to drop the boost down a little bit as well until I get my I/C installed. Quote Link to comment Share on other sites More sharing options...
Jersey Posted February 29, 2004 Share Posted February 29, 2004 525 - I posted this a few days ago but it somehow seems to be gone? Anyway, not sure if you replied but, i just had a few questions... 1. What's the final torque lb setting are you putting on the head bolts? 2. How many steps are you taking before you get to this final torque? 3. What tightening sequence are you using? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 29, 2004 Share Posted February 29, 2004 Jersey - I believe it was 55psi of torque on the bolts... basically I did it exactly as per the Haynes manual, as far as the order in which I tightened them. I didn't do it in 'steps' as when I did it I was just retorqueing them, I didn't install them originally. I dont know if the last guy who installed the head did them in steps. As it was, only a few of them even needed to be tightened at all when i checked them. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted February 29, 2004 Share Posted February 29, 2004 Regarding the oil...start the car, let it idle, and get the new oil circulating, drain it, change the filter and do it again. Continue to change it until you feel comfortable that you have gotten as much water out as you can. I believe that all the problems you had weren't due to detonation, but to the head gasket being a little crooked. It only has to be a little off to totally screw things up and missing an alignment dowel will do that in a heartbeat... Quote Link to comment Share on other sites More sharing options...
Jersey Posted February 29, 2004 Share Posted February 29, 2004 Got it 525. I thought this was like the 3rd head gasket that's went on you and you were the one re-instaling the head each time. Got my fingers crossed for ya that all goes well this time around. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted March 1, 2004 Share Posted March 1, 2004 Actually this is the first time a head gasket has failed on me. The head itself has failed twice now, both times due to a valve getting stuck and getting bent, the first time on my N/A motor, due to some very bad, old leftover gunk in the fuel tank, and the second time on the turbo motor for no apparent reason, but I've had no gasket problems even with the head going on and off so many times. I assume that dowel has been missing ever since I got the turbo motor.... Z-gad - you know... that pisses me off then... why do people never mention stuff to me like "hey one of these dowels is missing and this could screw up the whole thing"???? I guess I can't complain too much as it was a friend of mine helping me out to do it... this is when my rings were bad and he helped me 'rebuild' the engine while the block was in the car... but he's been working on his own Z's for a while I'd think he'd know how important something like a missing alignment dowel would be. *sigh* Little things like this... people just don't think that this stuff is worth mentioning and I end up paying for it later. Well... now I know, and at least it is something that is easy to look at and go "hey... here is the cause of this problem, which in turn caused this problem, etc." and there are no real mysteries about it. That's always good as with this car there have been WAY too many times that I just couldn't even figure out what was going on... and again it sure is nice not to have THIS particular problem on my conscience, as in it really isn't something I did wrong. Well... gotta order the parts I need from Nissan tommorow, head gasket and bolts and such, wont have them til the end of the week... car should be back on the road friday or saturday hopefully. Quote Link to comment Share on other sites More sharing options...
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