2008 VE L98 Chirping

[Qorx]

Went and looked at a 2008 VE with the L98 Motor (6.0L) and on cold start it was chirping.

It has 110,xxx on the clock with logbook servicing, however it didn't sound like the usual squeaky belt, it sounded more along the lines of a bird chirp.

I have read that it could be the start to something more sinister such as a lifter about to let go however I've read that it is a result of chirping when the motor is warm.

The engine was idling at about 600-650 rpm, which seems a tad low? I thought idling for most cars that were stock was around 800-850 rpm. Please advise?

The overall drive of the car seemed a little bit shitty, for example gears taking a little bit of lag time to change (Auto Transmission), a little laggy acceleration.

Any advice on this?

 

[FastR1Red]

Quite possibly the crankshaft pulley. OPen the bonnet, watch the pulley to see how much wobble it has. Safe but just the rubber mount could be out of spec. You might see 4mm of wobble.
Had mine changed and stopped the chirp altogether, plus no wobble of course.

 

[Qorx]

I was watching the harmonic balancer and it was wobbling a fair amount, wasn't spinning on a perfect symmetrical axis.

 

[FastR1Red]

Ok yeh that looks like it. If it's wobbling that much I would hazard a guess that's where the chirp is coming from. There was a TSB on this a few years ago.

 

[pnlimo]

Idle speed for an L98 (in drive) is normally 550 to 580 RPM

 

[VT2Commie]

Ask to see it and hear it running with both the belts OFF.

 

[Brettly-2008]

Serpentine belts can become glazed/shiny as they age and squeak as they run around certain metal pulleys. A spray of WD40 while running takes the glaze off instantly. It's a surprising fix for squeaky belts.

 

[VS_Pete]

Serpentine belts can become glazed/shiny as they age and squeak as they run around certain metal pulleys. A spray of WD40 while running takes the glaze off instantly. It's a surprising fix for squeaky belts.

So you just spray the outer side or both sides?

 

[monstar]

That idle speed is normal in Park or Neutral.
Now the 400kg Gorilla in the room nobody has mentioned is the LS chirp of doom. The easy way to check is make a mark on the crank pulley with chalk or some visual indicator and listen to the cadence of the chirp. If is slower like half speed of what you see then it’s camshaft related.
The major service issue with these engines (similar to the need to replace timing belts and chains on most other cars) is worn lifter roller(s) and / or cam lobe(s).
This occurs from around 100k km with poor lubrication servicing (or just plain bad luck) through 170k km over-servicing with the most exotic, expensive oils and filters.
I have done 340k km and replaced the (lifter) rollers and cam twice and expect to do it again at around 500k km. Best to do a full valvetrain overhaul at this opportunity, $2500 (google LS cam swap) else $1600 in parts DIY.

 

[someguy360]

I believe the cam bearings can also chirp in the LS when they fail.

I would put it down to Lifters, cam, cam bearing, I wouldn't be driving it any more until you know for sure.

If one of the lifters does let go completely you will throw metal through the engine.