big-phil Posted October 14, 2006 Share Posted October 14, 2006 I first noticed that the vent on top of the valve cover is blowing sorta white oily smoke out of it. Now I never noticed it before because when I had the n47 head on, I had a hose from the valve cover going to the intake just after the AFM. Also its building pressure. Isnt air suppose to be sucked in through there? Another bad thing is, I took a compression test, #1 was 150psi, #6 is 90psi. I don't think its a head gasket, I think its blow by from the pistons (thats the bad part) The funny part is, after the Z club meeting this past thursday, I raced, and beat a 300z turbo on the way home( he had stock boost) I'm set at 10 pounds. Here is my plan, tell me if I'm wrong. I have a turbo f54 block that needs a hone job (who dosn't?) Should I get it honed, check the crank, use the turbo rods that are in it. And just get another set of turbo pistons. Keep in mind that I am about out of money, I was just about to buy MSnS, and a fuel rail. But now I need a new(ish) lower end. Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 14, 2006 Author Share Posted October 14, 2006 :-( ok, I just bought a set of stock turbo pistons off e-bay from a motor that had 88k miles. there goes my MSnS money. :-( Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 14, 2006 Share Posted October 14, 2006 White smoke usually indicates headgasket. If you don't have a vacuum source hooked up to that hose barb on the valve cover, then it (and the block breather) will vent any pressure in the crankcase. So it wouldn't suck air in normally. If you have a shop in the area that does A/C services, you can usually get them to stick a sniffer (leak detector) in the top of the radiator. The sniffer will sense hydrocarbons, so if it goes off, then that would indicate a leaky headgasket. If the gasket is blown from the headgasket to a coolant passage, that would make the compression test low and cause the white smoke. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 14, 2006 Share Posted October 14, 2006 that is a good idea, never would have thought of doing that Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 14, 2006 Author Share Posted October 14, 2006 Its a brand new head gasket. With a fresh p90 head. Could I of gotton a bad head gasket? Also when I took the n47 head off, and the intake tube from the AFM to the turbo off. I noticed an oily residue from the hose leading upto the valve cover. Like it had been doing this for some time before I tore it down. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 14, 2006 Share Posted October 14, 2006 blow by, sounds like rings, had same problem awhile back Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 14, 2006 Author Share Posted October 14, 2006 yea thats what I'm thinking. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 14, 2006 Share Posted October 14, 2006 OK, well if it's rings put a little bit of oil in #6 and redo the compression test and the numbers should jump right up. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted October 15, 2006 Share Posted October 15, 2006 If you look at one of the pictures in your post about the Holset install you'll see that one of the pistons looked less than perfect. Looked to me like detonation had gotten the better of it a couple of times. I'm thinking possibly broken ring lands. What would a leak down test show us? Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 15, 2006 Author Share Posted October 15, 2006 If you look at one of the pictures in your post about the Holset install you'll see that one of the pistons looked less than perfect. Looked to me like detonation had gotten the better of it a couple of times. I'm thinking possibly broken ring lands. What would a leak down test show us? one of the pics was of the turbo block with the bad pistons in it. I'm going to hone out that block, and put the turbo pistons I got off e-bay for $80 in, with new berings. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 16, 2006 Share Posted October 16, 2006 Did you try a couple squirts of oil and redo the compression test? That would tell you for sure if it was rings. If the compression #'s don't jump right up, then it's leaking somewhere else, out of a valve or headgasket or something. Takes 5 minutes... Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 16, 2006 Author Share Posted October 16, 2006 Did you try a couple squirts of oil and redo the compression test? That would tell you for sure if it was rings. If the compression #'s don't jump right up, then it's leaking somewhere else, out of a valve or headgasket or something. Takes 5 minutes... OK I'm goin out to do it right now. Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 16, 2006 Author Share Posted October 16, 2006 It took me about 8 min, but I got a phone call. It went from 90psi to 130 psi so thats the rings right? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 16, 2006 Share Posted October 16, 2006 Yep. At least now you know for sure... Quote Link to comment Share on other sites More sharing options...
240zV8 Posted October 17, 2006 Share Posted October 17, 2006 I hope to have a Z in the next couple weeks, and I will be donating to this site right away just for the simple fact that it's a godsent for newbies like me, i've learned so much from reading here.......U could make a manual for almost any mod or fix on a Z from this site. Quote Link to comment Share on other sites More sharing options...
Chris240zTurbo Posted October 17, 2006 Share Posted October 17, 2006 Phil, Chris here, we met a few months ago at the FTW Z club meeting, I have a virgin bore F54 turbo short block sitting in my shop I'd sell you for $150 if you're interested, all stock, but crank journals all look good, as do pistons, it's disassembled, I was going to throw new bearings, rings and gaskets at it and sock it away for some unknown future project, but you're welcome to it if you need, heck, buy some bearings and rings and a 12 pack and come over here and we'll put it back together too... wish I'd seen this before you bought the stock pistons, as I have maybe 4 sets and I'd have just given you a set of usable ones. bummer, I just don't get online much anymore. anyway give me a call 817-593-9265 Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 18, 2006 Author Share Posted October 18, 2006 Hey Chris, I would like to come out and see what you have, and also get some info on putting the motor back together. I tried your # but it didn't work. I'll pm you my #, I'm scarred to put it up here. Its my work # also. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 18, 2006 Share Posted October 18, 2006 yea you gotta watch out for stalkers, lol. rings huh? hope all goes well in the rebuild. i have an extra motor sittin too, but its the "just in case" motor. i also have a "just in case" 5 speed and 4 speed. im a pack rat for short. Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 18, 2006 Author Share Posted October 18, 2006 thats agood thing to do. All I need is a "just in case" wife, and I'm all set! Quote Link to comment Share on other sites More sharing options...
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