Cobra4B

iTrader: (9)

Car is a 2001 Z06 with a LGM G5-X2 cam and stock heads. Car has 85,xxx miles on it, cam has been installed since 69,xxx in January 2007. Has comp 921 springs and stock rockers. Took some YT ultralights off earlier this year when I condidered selling the car. Pushrods are 7.4 comps that come w/ the LGM kit.

I've rarely driven the car over the past 6 months as I've got lots of other stuff going on w/ a kitchen remodel and house stuff. I notice that she clatters a bit when first driven after sitting a few weeks, but it's always done that.

Drove the car to the gym last night and to work today. Driving around today w/ the radio off the ticking has gotten a bit louder to the point that it's a defininte "tick" and not just LSX sewing machine etc. etc. It's not 100% uniform, it sounds a bit like morse code at idle, but that may be due to slight idle variations w/ the cam. Once rolling you can faintly hear it follow rpm, but it quiets down considerably, to the point where you probably wouldn't notice it if you weren't listening for it.

My assumption is that one of my 10 year old 85,000 mile lifters is finally showing signs of wear. That said what's the best way to diagnose this? What else could it be?

With the hood open and the fuel rail cover still in place it seems that it's coming from #6 area. Doesn't act like an exhaust leak i.e. quiet at idle, but more pronounced under load.

When re-installing the stock rockers I used blue loc-tite on the bolts and I've never ever had one come loose, all though pulling the valve-covers and checking that would be the first thing to do.

Assuming the rockers are tight and the springs all look fine, the next in line is the lifters correct? The car could use fresh lifters regardless, but I don't really want to pull the heads right now... I mean if I'm going to pull the heads I might as well have them ported, but I'm currently spending a bunch on my kitchen remodel and Christmas gifts have taken up fun money too.

Thanks in advance for any input.

-Brian

Cobra4B

iTrader: (9)

Anyone?

WKMCD

iTrader: (2)

Hey Brian,

The first thing I would do - and I'd do it fast - is pull the VC and check out the rockers for needle bearing loss.

Does the sound go away with RPM as the oil pressure increases?

Cobra4B

iTrader: (9)

Yeah... sound goes away as rpms climb... sewing machine/exhaust take over. Driving home tonight w/ the radio off it was back to "normal". Could hear a little faint ticking at idle, but nothing that made me say "hey what's that tick?". I've driven older trucks with bad lifters and it sounds no where near as prominent as that.

For all I know a lifter bled down as the car sat and was acting stickey... going to drive the car more and listen.

She could use new lfiters anyway, but I don't care to do the work right now.

YoMommasTA

iTrader: (1)

Try some Rislone in the oil, might just be a little dirt.

Cobra4B

iTrader: (9)

I doubt it... fresh oil change 1100 miles ago.

LS12Fast4U

iTrader: (1)

I would still pull the Valve cover and check the needle bearings. If its the rockers you could be looking at a lot more money down the road if you dont catch it now. Better safe then sorry and if they look fine you can at least rule them out.

Cobra4B

iTrader: (9)

Sound has gone away... gone back to normal clatter. I think a lifter must be getting stickey... will pull the passenger side VC to check the rocker arms regardless.

WKMCD

iTrader: (2)

Can hurt. It's not a bad idea to install the new Comp trunions in the rockers.