mehul7 Posted February 26 Share Posted February 26 Hoping to get some ideas on what could be causing this ticking noise? 1977 Datsun 280z. Here is what I have tried so far - replaced timing chain, guides, sprocket and tensioner. Set timing to 10btdc, adjusted all valve lash to be in spec and tested compression on all the cylinders( front to back - 150,140,135,135,135,135). disconnected each spark plugs as the engine is running and the noise was still there so it probably has to be valve train related. Also when I touch the valve cover with a screwdriver the vibration seems to be strongest in the middle of the valve cover. Could a spring be hitting the camshaft bearing? GDDLnhm60J_KldsDAEz2D7tkz1FSbmdjAAAF.mp4 GJaNnBla4XuO2VYBAI8IT-CrJ5MMbmdjAAAF.mp4 GPPBjBkBAzve4twDAAZ6Ijg7PB0RbmdjAAAF.mp4 Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 26 Share Posted February 26 (edited) These overhead cam rocker arm manual lash adjustment engines are naturally noisy. Have you adjusted the valve lash? It's the first item in the Nissan FSM tune-up chapter. By the pictures and video, your lash is certainly not too tight. It looks a little loose, by the extent of the brown on the cam lobes. It doesn't sound terrible. It might even be an injector. You can disconnect the injectors with the engine running to see. Pull the clips so the injector plugs are loose, put the valve cover back on and let it run. Pull each injector one by one and see if anything changes. If the noise is still there after adjusting lash. . . . Edited February 26 by NewZed Quote Link to comment Share on other sites More sharing options...
mehul7 Posted February 26 Author Share Posted February 26 Thanks for your reply. I adjusted the valve lash and some of them were a bit loose but not anymore. and the noise still persists. I was gonna unplug the injectors to check but i tried touching each injector with a screwdriver while the engine was running and couldn't feel any vibrations so i assumed they were fine. but i can try to pull each one and see what happens. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 26 Share Posted February 26 (edited) Sometimes a rocker arm will just be noisy. Has any work been done on the head? You might check the wipe patterns on the rocker arm wear/rubbing pads. Where the cam touches the rocker arm. It's not uncommon for people to get the wrong lash pads installed. I've even seen where the cam lobe runs off the end of the pad. https://www.classiczcars.com/forums/topic/50485-rocker-geometry-woes/ . . . Edited February 26 by NewZed Quote Link to comment Share on other sites More sharing options...
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