Bwales Posted December 13, 2017 Share Posted December 13, 2017 I have read on multiple forums about broken valve springs, wrong adjustments, stuck valves etc. So I went for a short trip to my local club meeting in my 240z(l28) and came back with no issue. I tried to start it up the next day and it was noisy (valve train). I opened up the valve cover and found not one but THREE lash pads off. What the heck could cause such a thing? This car had sat for a very long time before I got it and I have less than 1k mikes on it since I bought it. On its second oil change since not sitting up. Quote Link to comment Share on other sites More sharing options...
rossman Posted December 14, 2017 Share Posted December 14, 2017 Are any of the valve stems/caps damaged? Maybe the lifter backed all the way down, allowing the lash pad to slip out. Quote Link to comment Share on other sites More sharing options...
HuD 91gt Posted December 14, 2017 Share Posted December 14, 2017 When I popped a lash pad, a valve ended up knicking a piston. Stainless valves were too tight in cast guides and with the heat of normal engine operation lodged a valve stem in the guide and the piston tapped the valve. i noticed looking through the spark plug hole and seeing the minor marking on the piston. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted December 14, 2017 Share Posted December 14, 2017 Have you done a valve adjustment? These aren't shimmed buckets like in modern cars, they have tolerances that need to be adjusted at a regular interval. Quote Link to comment Share on other sites More sharing options...
Bwales Posted December 16, 2017 Author Share Posted December 16, 2017 So the valves were adjusted a few weeks ago. On the three valves that threw the pad, the springs seem either really weak or the lifter seems stuck. The rocker will barely contact the pad. I can't imagine it being that far out of adjustment so soon. Quote Link to comment Share on other sites More sharing options...
Bwales Posted December 16, 2017 Author Share Posted December 16, 2017 Sorry not lifter. Valve seems stuck. Quote Link to comment Share on other sites More sharing options...
rossman Posted December 16, 2017 Share Posted December 16, 2017 Could be dropped valve seats on those three. Have they been replaced recently? How do the valve tip/retainer heights look compared to the others? Quote Link to comment Share on other sites More sharing options...
Bwales Posted December 17, 2017 Author Share Posted December 17, 2017 The retainers look to be the same all around. I did witness one getting stuck and I tapped it and it popped back up. I just hoping it isn't bent. I am hoping to buy a compression/leak down test kit so I can see if they are seating properly. Quote Link to comment Share on other sites More sharing options...
BJSZED Posted December 17, 2017 Share Posted December 17, 2017 I had this happen on an L28 that sat for a long long time. The valves were all gummed up from trying to run it on old stale gas. PS, you should correct your thread title. I wondered what lap pads were ? Quote Link to comment Share on other sites More sharing options...
seattlejester Posted December 19, 2017 Share Posted December 19, 2017 Lash pads right? I thought that looked funny. If you didn't tighten the lock nut it wouldn't take much to loosen and come out of adjustment. Granted if it is sticking that isn't really an adjustment thing as it is a bent valve stem, debris in the valve guide, or something of that nature. Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 19, 2017 Share Posted December 19, 2017 (edited) What engine / year? Update your signature. Not that uncommon in an early head that has sat too long bronze seats , gummed up guides . My 71 did that also. The valve sticks and the lash pads turn on the retainer and get kicked off. Not real fix but you could try some Marvel Mystery oil in the oil and gas . I would fill my car up at the airport( years ago) with 100LL and seemed to help. Sorry - just saw that you put that it was a L28 , so disregard the early head stuff , but still might be a gummy issue Edited December 19, 2017 by madkaw Quote Link to comment Share on other sites More sharing options...
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