jsbzoh6

2008 Z06 with 40k miles on it. The oil is about 2 months old, maybe 2000 miles. Mobil 1 5w-30 with Mobil 1 oil filter.

I know, I know, the LS7s are noisy. I've owned mine for about 6 months now and while I don't drive it much, it's definitely developed a new noise that is a bit worrisome. With the hood closed and the car at operating temperature, it almost sounds like an exhaust leak. Hood open, it has almost a knock sound to it. Inside the car, it sounds like a definite "tick".

I took two videos:

This is outside the car, being revved to 2k RPM then up to 3k.


This is harder to hear, but it's louder in person. The tick stays consistent at all RPMs (louder/faster as they raise).j

I've tightened up all of the exhaust components and can't feel/see any leaks. I've listened with a screwdriver to the valve covers and I don't hear any abnormal noises, it almost sounds like this noise is coming from underneath.

OhioC5

I wonder if one of the rockers has lost some of the needle bearings. I'd pull the valve covers at least and take a look.

Dirty Howie

damn computer at work has no audio. will listen to this tonight ...


DH

dkz

sounds just like mine.

Vito.A

Is the car 100% stock?
Have the valve guides been reworked?

Dan_the_C5_Man

I am assuming it is only on one side, yes?

Think about it - identical components on both sides of the engine, no logical reason for one to be much nosier than the other, unless there is a problem.

It is either a lifter or something up top - Pull the valve cover on the side that's noisy and investigate.

If you are nervous about doing this, at least buy yourself a decent mechanics stethoscope, try to pinpoint where it is coming from.

If the noise has a deeper tone, probably lifter-related (collapsed, spun, roller went bad (although those usually squeak at some point)). If a higher pitched tone, I would focus on the rocker arms.

The stethoscope should help pinpoint the source.

jsbzoh6

I took off both valve covers and didn't see anything glaring at me but I didn't know what to look for on the rockers. I just found the thread about them failing so I'll take everything back off this weekend and look. I didn't see any debris or anything out of place and all the springs were intact.

The car is 100% stock. I'm not sure the history on it before I owned it, but I have not had the heads looked at.

That's the confusing part. Inside the car, it almost sounds like an 80s truck low on oil. Tick, tick, tick. But outside the car it has that deeper knocking sound. It's definitely louder on the drivers side but I can't pinpoint the sound (as in listening with a screwdriver to the ear on both left and right sound roughly the same)

I had the valve covers off today and didn't see anything glaringly out of place. This weekend I'll change the oil and see if there's anything in there. I'll get the valve covers back off and check for any rocker arm failures (Nothing seemed damaged today, but now I know what to look for)

dart.deanda

Mechanics stethoscope is $5 at harbor freight. Put it on and just to the left and right of the bolts that hold the valve cover on the head.

Dirty Howie

Definitely noisier than normal in my opinion


DH

subfloor@centurytrans

That's definitely a bad lifter.

meanjoe

A stock LS7 with 40K miles on it, and we're wondering what the noise is?
I pulled my heads at 3400 miles, valves were toast. I'm wondering what the problem here may be?????

ATC399

Well ***** (cat) poster...Every thing is not valve related...13Z 14k no issues...just sayin

fueledpassion

But if the lifter is bad, it can eventually screw with the geometry of everything it is connected to - rocker arms, pushrods, etc.

Rocker arms are a large concern for premature guide wear, so I can see how this could lead to that which could lead to a dropped valve 5K miles down the road.

But on the other hand, here is a good quick excerpt on lifters:

'Worn lifters, or excessively low oil pressure, will often produce a clacking or clicking sound, especially during engine warmup. The sound originates from collapsed hydraulic lifters that are frozen, or from solid lifters that have worn excessively and changed lash tolerances. An engine miss usually accompanies a bad lifter, usually originating from the affected cylinder. Lifter noises should not be confused with arcing or snapping spark plug wires.'

El Paso Vette

I have an 09 with 42,000 miles and yours sounds like every other LS7 I have heard. These are very noisy engines. By the way I worry all the time about this and my car seems to keep on working very well. No noises like have been posted before.

RamAir972003

Yes sounds like a lifter.....def louder than regular ls7

subfloor@centurytrans

It's definitely a bad lifter.

1972bluelt1

This sounds much worse than the OP to me.

jsbzoh6

This is similar, but not nearly as bad. There also isn't the squeak/squeal. There are no other abnormal noises other than the specific sound. I watched other bad lifter videos and they all seem to have that squeak?

subfloor@centurytrans

The presence of the squealing sound corresponds to how far along the problem happens to be at the time. The video shown above was taken after the guy had driven the car for several hundred since the problem started and was initially much quieter and VERY similar to what yours sounds like.

Although this happened a few years ago, I seem to remember that when I pulled the plugs there were one or two that were noticeably different in color than the others which was a result of the lifter causing the valve to not open as much as it should. I would recommend checking your plugs to see if there are any differences as that might give you an idea which cylinder has the problem.

The other thing you might want to try doing is remove the intake manifold and valley cover. Although the lifters are pretty well hidden inside the motor and require the heads to come off in order to change them, with those two parts removed you can actually see the lifters for cylinders 1,2, 7 and 8 (8 of them in total) resting up against the camshaft. Using the car from the video again as an example, when I did this I was able to see noticeable scoring on one of the camshaft lobes caused by the roller which had gotten messed up.

Ninety-Nine FRC

Best time to replace the lifters is when you have the heads gone over, milled, cam, long tubes, intake, and tune.