zfann Posted March 31, 2012 Share Posted March 31, 2012 In the past I’ve never experienced any mechanical issues with this engine, just done regular maintenance, some upgrades. Unfortunately car has not been driven for close to a year. Last time I drove it before it run fine. Couple months ago I finally started it only to find out it was running extremely rough, w lack of power in first couple gears… Today I finally pulled the valve cover off just to find out the rocker slipped of the valve. Then I noticed the two parts floating around… Maybe the pictures will explain better: How would I go about putting everything back? Do I need to be concerned about why this happened ? Any advise would be great, thx in advance. Quote Link to comment Share on other sites More sharing options...
akeboshi Posted March 31, 2012 Share Posted March 31, 2012 The other valve keeper is in the valve stem still so your motor is probably ok internally. I had a problem with a rocker that kept falling off. Incidentally it wiped the cam lobe later on a cwc cam from comp. I would inspect the top of the valve stem and if there is no visible damage or wear, throw some different keepers and a new rocker in there and call it a day. Unfortunately if the top of that stem is damaged or worn in any way its gonna have to come out. Just snag another valve, hand lapp it with some lapping compound and you should be good to go. they sell the compound at autozone. Quote Link to comment Share on other sites More sharing options...
TimZ Posted March 31, 2012 Share Posted March 31, 2012 Do I need to be concerned about why this happened ? Not trying to be a ****, but what do you think? Does that look normal to you? The two parts are the lash pad and one of the two valve stem locks for that valve - the other one is still in the spring retainer where it belongs, precariously holding the retainer on the valve and keeping the spring in place. This generally only happens if the retainer loses tension on the end of the valve for some reason. If I had to guess, I'd say that the valve got stuck open for some reason (valve bent, problem with the guide, valve seat fell out, or similar) which allowed the rocker to come off. Next, from the apparent witness marks on the retainer, I'd guess that the rocker came to rest on the retainer itself and the next time or two when the cam lobe came around it pushed the retainer down and popped the lash pad out and dislodged one of the locks. Sorry to say, but unless you find a smoking gun that says otherwise you're going to have to pull the head to see why this happened and remedy it. If you just put it back together it will almost certainly happen again, probably with worse consequences. Quote Link to comment Share on other sites More sharing options...
zfann Posted April 1, 2012 Author Share Posted April 1, 2012 Not trying to be a ****, but what do you think? Does that look normal to you? You are right, that was a dumb question... I think to be safe further investigation is in order... this is however beyond my skills/abilities,so does anybody have recommendation for a place to take it in Phoenix? Quote Link to comment Share on other sites More sharing options...
ctc Posted April 1, 2012 Share Posted April 1, 2012 Bryan Blake of Blake Machine, Phoenix, Arizona Quote Link to comment Share on other sites More sharing options...
johnc Posted April 1, 2012 Share Posted April 1, 2012 Did you run the engine rpms up around 7,000 before this happened? Maybe a bad downshift? Quote Link to comment Share on other sites More sharing options...
srgunz Posted April 2, 2012 Share Posted April 2, 2012 Years ago my friend did that on a test drive after installing a cam kit. He missed a shift, hit about 8000 rpm and I believe 3 rocker arms cam off. Was a 71 with the early gearbox. Had to pull head and do over. I thought it was funny at the time. Quote Link to comment Share on other sites More sharing options...
Sam280Z Posted April 2, 2012 Share Posted April 2, 2012 "car has not been driven for close to a year" old gas can varnish and be like glue on the valve stem - making the valve hang open and/or close too slowly... Sam Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted April 2, 2012 Share Posted April 2, 2012 "car has not been driven for close to a year"old gas can varnish and be like glue on the valve stem - making the valve hang open and/or close too slowly...Sam This exactly happened to my friends fairlady zx. It had like 5 yr old gas, and I actuall had it running and driveable. Randomly when I started it after 2 weeks of driving it every day around the block, it randomly started running like crap. Pulled the valve cover off and saw the same thing. When he went to have it checked out they said the old gas caused a valve to stick. Quote Link to comment Share on other sites More sharing options...
Gollum Posted April 2, 2012 Share Posted April 2, 2012 If it were me, which it's not, since the motor hadn't been run in a while I'd take to opportunity to pull the head and inspect everything. Clean the piston crowns, chambers, etc. If you get as cheap as possible you can do the whole job for the price of a head gasket + intake/exhaust gasket ($50 tops). But while you have it out and getting it cleaned you can rent a spring compressor and check out your valves plus learn how to use a new tool if you've never pulled valves before. I'm personally thinking old gas could be a serious contributor here. You could also upgrade to the viton valve seals while the head is off and valves are out. Those go for like $50 a set right? You'll want two sets as you will undoubtedly break a few (even pros do from time to time). Another contributor could be if that valve's stem seal was already leaking and you still had nasty old oil in the engine. My engine goes through a quart of oil every 1500 miles or so and I'm kinda expecting to lose a valve eventually.... Quote Link to comment Share on other sites More sharing options...
srgunz Posted April 3, 2012 Share Posted April 3, 2012 I agree. It does sound like a stuck valve. However several times since I have owned my Z, it sat for a year or more and never had a valve stick when I drove it. Guess I was just lucky. Quote Link to comment Share on other sites More sharing options...
josh817 Posted April 3, 2012 Share Posted April 3, 2012 I had the same thing happen to me except the rocker came completely off and was sitting in the oil alley thing in the center of the head as well as the lash pad. This happened when I was testing RPM's, slowly going up through the range and right about 6500-7000 it took a dump. Was only taking a dump because the exhaust valve wasn't opening at that point. I put it back on and it ran like a clock as usual. I guess maybe valve float, possibly a stuck valve but I don't think I made the motor an interference fit. I had posted a thread on it a long time ago when it had happened but no one responded. Basically just me asking if the mouse trap springs are necessary but seeing how it held your rocker on, I guess so! Maybe mine was more violent. Keep in mind my Z was a daily driver so no rotten gas. Quote Link to comment Share on other sites More sharing options...
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