VZ V6 engine tick

[CRUSTIN]

Hey guys. I started up my car tonight in the garage with no noise going on, and i heard a tick in the engine bay. It runs with engine revs, but not engine speed, more like valve tap.

Has anyone had tappets loose enough to tap, are they ever adjusted in a service schedule? Or is it more likely a stuffed cam follower?

The reason i'm so worked up about it is because i had the exact same symptoms(valve speed tap, vibration at around 1500rpm, slight decrease in performance) at work, but it was in a cng bus engine.

[impulsive]

perhaps get a video up, i had a 'tapping' that turned out to be a timing chain tensioner

[vz_sv6_owner1990]

When you say cng bus... Who do you work for?

[2005vzute]

hahaha the tapping in cng bus engines being valves, you're laughing haha, a tap in an engine at my work is more like valve recession or piston knock hahaha, as for your problem, i've heard a coupla timing chains ticking, valves can't be adjusted on alloytecs, they use hydraulic lash adjusters instead

peace.

[CRUSTIN]

Thanks for the replies, good to know about the hydraulic valves. Ive heard that the timing chain is a job and a half to get to. Worth changing chain as well? And can i get an aftermarket chain, apparently the oem chains are noisy. The tap is barely noticeable, and my exhaust noise would kill a video mic.

I work for brisbane city council, and as for that bus, it was a MAN(MAN valves get tighter, not looser). The bus had a tick at full revs, and vibration at 1500. We did compression tests, missfire checks, valve adjustments. But when we turned the engine over with the tappet covers off for the 3rd time, cylinder 4 intake valve only traveled 3mm. to the naked eye it almost looked like it didn't move. The cam follower's hardened surface had failed and it wore the cam lobe flat. That's an expensive problem.