I have a 1976 280z and when I crank it up it has a light knockit sounds like the valves are loose but has been adjusted 3 times.. was told it could be timing chain hitting the chain guide everything looked fine chain is not loose.. with valve cover off it seems to be comming from a valve. towards the firewall..
Anyone have any ideas it would be great!
Thanks
Wierd knock while running 280z - help plz!
Re: Wierd knock while running 280z - help plz! (KenSR20)
Check Timing. Also check VALVE timing. Too low gasoctane/too high engine compression. Engine overheating. Carbon build up onvalves. An improperly torqued knock sensor can cause the sensor to notfunction correctly resulting in knock and/or loss of power. Failing knocksensor. These are some of the possible reason.
Re: Wierd knock while running 280z - help plz! (KenSR20)
A guy at work has the same car but I think his has the 2.4 w/ twin side draft carbs. I think those originally came fuel injected. Ah hell I have no idea what I'm talking about. Anyway, He noticed a knock in the top of the motor and It was a wore out rocker or something. One of the oldskool guys said it was fairly common back in the day. I can get more info. Like I said I have no knowledge of these cars.
Re: Wierd knock while running 280z - help plz! (carmo)
Okay, the dood at work has a 240z with an L28 motor swap that was converted from fuel injection to carbs. Not sure why. Take the valve cover off and look at where the rocker arms contact the cam. From the factory the arm had a convex shape to it but over the years they wear into a concave shape. Once this happens, you cant adjust the noise out of it. Apparently sometimes the rocker will even wear the cam out. Hope that helped....