george.bryant Posted January 1, 2006 Share Posted January 1, 2006 Recently my car has started doing some funny stuff. Its running pretty rough on startup, kinda feels like its missing or something. And on acceleration it stumbles kinda and feels like a subaru. I've checked the spark plugs and they were ok except for #6 which had quite a bit of oil build up on it and smelt like unburnt fuel. I cleaned them all to see if that was the problem. Put them back in car and started it and it ran good for about 1 minute then started doing its stumbly thing at idle... I had a play with the ignition timing aswell to try to see if i could set it straight, found a good setting for timing with the 10psi that i run so thats ok. But after driving that car for about 20 minutes it just got even more stumbly, but on boost you dont even notice it. I put a new distributor cap on yesterday aswell. the car is also drinking water slowly. Using about 400ml a day (i just topped it up with more or shell's coolguard). My lead are about 4 months old, one day i noticed they were leaking spark so i taped them up and i never noticed it again. Is the problem that i need new leads? Or what. I used to get a vacuum or between 17-18 at idle. Now its at like 14-16. Thats why i set the ignition timing. I dont know what to do. I have a feeling headgasket might be cracked somewhere as my water looked very mildly contaminated but my oil looks fine (its about 3 months old). Help.... Regards, George. next thing i type on another forum: ::Too make matters worst, last night after i got everything back together and went for a drive to test it out, it seemed to be running ok. Driving down the motorway i hit 105 and hear something in the back go clunk (not a big clunk but enough to notice it, and sounded like a tool falling off and hitting the ground [but i wasnt using a tool or doing anything to the diff]). It got pretty bad but only at 1550 rpm to 2150rpm on coasting, it was making this noise like a a broken gear, kinda like a clock ticking but also clunking it was pretty mild. Anyway i needed my vehicle so had to keep driving and couldnt really just stop on the motor way. I drove 15 km to SuperCheap Auto spares to get a new spark plug and lead for #6. As i was pulling into their carpark it started to misfire and was heating up pretty bad. Looked in the coolant bottle and it was pretty gross looking in there. Was contaminated with oil about 10%. I went and got the lead and plug, i put the lead on and drove home. It was a horrible drive, i was trying not to hit boost at all but i hit it once and big cloud of white smoke shot out the back. I thought "there goes the head gasket". The rest of the drive for about 13km involved horrible noises coming from the rear end (the ticking clunk noise) and and feeling insane amounts of heat coming throught he firewall and my heater system. I pulled into the garage and gave it a little rev and there i saw the white looking steamy **** again. which i experience at pretty much the same time last year on this same motor. I've learnt alot since then and reckon i could change the gasket and i probly should as about 4-5months ago i sealed a leak with a chemiweld radiator additive as when my old radiator was in the process of blowing up, it caused a water leake between the head and the block and water was spraying out between the two. Is it worth changing the gasket? I reckon it is since i cannot afford a new motor at the moment. I have a spare head but i need to get it crack tested, and ive taken out the cam so i need to know how to put that back in and align everything up. The thing that daunts me with taking the head off my motor is that I do not know how to get the timing chain off correctly, or set its timing again. And im freaked out that I wont be able to get it running or something stupid will happen, or that ill get it all back together and itll overheat and blow a gasket again. I know how much of a bitch it is to get the manifolds off these motors (L20et) but i'm on holidays for 2 weeks and i have another car to use so i was thinking id give it a go. So i was wondering what you guys think? And was hoping you'd all be willing to advice me on what i need to do. Regards, George Quote Link to comment Share on other sites More sharing options...
Here comes trouble Posted January 1, 2006 Share Posted January 1, 2006 George . sounds like the head gasket developed a larger hole..and now beyond a quick fix in a can or bottle..ie head gasket replacement and possible head shaving...... jack the rear end up with both wheels off the the ground in neutral gear and do some manual spinning and turning of tires,drive shafts etc to locate the clunk. Good luck! Looks like you are gonna get on a personal level with your Z in the next two weeks. Quote Link to comment Share on other sites More sharing options...
george.bryant Posted January 1, 2006 Author Share Posted January 1, 2006 larger hole very true! With that spare head i had, I was thinking instead of wasting money on a crack test (NZD$40). I would just get it shaved a bit. How much should I do, what is the min? Is it ness to get a check? Also what should i do in terms of valves, springs, lifters; etc ?? My budget is low. oh! ive been personal with old Paul Newman a few too many times lately for my liking (i have a '83 KHR30 Skyline, not a Z) Quote Link to comment Share on other sites More sharing options...
Here comes trouble Posted January 2, 2006 Share Posted January 2, 2006 George ... lay that head upside down and grab that square you inherited from grandpa and lay it's straight edge across any flat surface around the combustion chambers in any direction you can on that upside head. If you see any daylight..between the straight edge of the square and head surface..... the head needs a shave. You need to get down and eyeball that head surface while holding that straight edge square on the head surface with one hand.... while looking for any space (daylight) between the square edge and head surface.. You can lug the head into about any automotive machine shop for a second opinion for free. The alumuum head is subject to warpage from over heating but some times a fellow gets lucky and does not have to mill the head Quote Link to comment Share on other sites More sharing options...
1 fast z Posted January 2, 2006 Share Posted January 2, 2006 The human Eye can see daylight in as little room as .0002", so You need to FEELER guage it, not "if you see light". .003" will work BTW. Quote Link to comment Share on other sites More sharing options...
george.bryant Posted January 2, 2006 Author Share Posted January 2, 2006 cheeres alot guys, i jsuyt went out and bought some extension bars and a torque wrench, time to go pull those manifolds off!! Quote Link to comment Share on other sites More sharing options...
george.bryant Posted January 2, 2006 Author Share Posted January 2, 2006 ok get this! I got out and start doing some more work...i went to drain the radiator (that is only about 4 months new with a new bung) and my screw-drvier stripped the bung!! The only thing I can think of to do, is to drill through it, pull it out and replace it with a more durable bung. God how annoying. Quote Link to comment Share on other sites More sharing options...
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