Looking for suggestions of plausible causes ? Car Recently at the Mechanics and now has quite an audible – (Tick at idle) – but disappears once the revs increase. Initial thoughts - Sounds like lifter tick ? If anyone knows my car it’s pretty much a Garage queen. – only gets registered for 3 months a year and rarely driven throughout that period. The engine has always suffered from the dreaded VCT rattle – so (7 years) back I purchased a set of Custom - BDE – intake gears – but never fitted. Last year I bought a set of – BDE – adjustable Exhaust gears. Finally got around to having them fitted. The Brief: The Bad: While fitting the R/H side intake gear the mechanic made a rookie mistake and missed the camshaft snout adapter behind the intake gear – resulting in snapping the nose off the JWT R5 cam. Now while sourcing a replacement CAM from CoZ – he tells me it happens all too frequently. Fast forward a couple of weeks. So New R/H side - JWT R5 cam replaced, New BDE – intake cam gears fitted. New BDE – adjustable exhaust cam gears fitted. Replaced the heavy duty VCT springs to stock springs. New - Hydraulic plunger on the Auto tensioner. Timing Belt – refitted. Set the Exhaust gears - (minus 5) degrees. Ran the engine to Bed in the New Cam. Made a run on the Dyno to get a base line – Had to pull some timing out it and add fuel as noticed some detonation. - (add the factors of a 40 degree day) into that. So prior to spending a heap of time on the Dyno to fine tune the new gears ect… I’ve got my concerns on this new issue – the idle Tick ? It Sounds really metallic – but as soon as you increase the revs – it disappears ? Almost like its lifter tick ? Injector – Tick ? It’s only present at idle though. But sounds like its coming from both sides of the camshaft covers ? – note - (only the R/H side cam was replaced). My next step is to - reset – the exhaust gears back to (0) to see if it makes a difference ? So looking for Any ideas / solutions to try. Thanks in advance Trevor (2ZXTRM)
Put a screwdriver to your ear and against each injector (be careful not to get caught on anything moving). You will be surprised how metallic some injectors are at idle. Give it a rev by the throttle on the engine end while listening. The noise tends to quieten on revving.
Vtc noise will only make itself known when vtc is off (at idle). Lots of reports on bde gears making noise again after being installed. I have early bde gears, one is noisy. I'm about to replace them with s2 adjustable gears. First things first, put your hd springs back in.
Yes that was on my mind to try first up - put the HD spring back in? and also activate the VCT solenoids - to see if it makes a difference.
Maybe don't install the HD springs https://aus300zx.com/xenforo/index.php?threads/vtc-sprocket-info-from-bde.311690/
While the engine is idling and making noise, manually activate the VTC by grounding one of the green with black stripe wires while the solenoids are connected to the wire harness (or use a Consult interface). If the noise disappears, then the gears are making noise. Several reasons for VTC noise that are not necessarily the VTC's fault: 1)cold start, high oil pressure - noise typically goes away after the engine oil warms up (see #3 below for description). 2)valve springs installed pressure above 80 lbsf. 3)oil viscosity higher than SAE 40 - thick oil cannot escape through the center of the cam fast enough and builds pressure at the VTC which helps to unseat the VTC piston. I encourage anyone who's experiencing VTC noise with my rebuilds to check the list above and then contact me to discuss options.
Plenty of people with R5 cams (myself included) experienced some minor VTC rattle still with BDE gears. Just have to live with it.
Valve train noise with JWT cams is more likely to be due to increased cammshaft/lifter clearance which reduces the preload on the lifter that is required for bleeding. This is an inherent issue with the design of their cam shafts, and not a fault with the VTC mechanism.
