Top end clatter / lifter tick?

[Dynomite]

Originally Posted by cmb

Assuming that I do need to replace lifters, can this be done with the engine in the car?

--Colin

No...I would say not.....hard to remove cam covers engine in car and very difficult to set camshaft timing engine in car.
Having said that....it is definitely worth removing one or both cam covers with engine in car to inspect camshafts and lifters for strange wear patterns or damage of any kind. When Cam Covers are removed do NOT get the idea you can start the engine to listen/watch as the Cam Covers are the top bearings for the Camshafts. You can however (with Cam Covers Removed), rotate the crankshaft slowly by hand with a long socket wrench on the Harmonic Balancer Bolt and watch for a sticky lifter or other aberations. All lifters in this case will be/will collapse if left sitting for several hours with lifter compressed since there is no oil pressure to pump them up.

Another idea......remove the serpentine belt and fire the engine up just for a minute or two. That will eliminate any noise from the Alternator, AC Compressor, Belt Tensioner, Power Steering Pump, or Water Pump.

Originally Posted by Jagdpanzer

Video sounds nasty.

I concur.....

Originally Posted by We Gone

Lifter or maybe a bad valve spring?

I concur ......but listening to a cell phone rendition of an engine noise is very very difficult to diagnose.
The LT5 engine does make some normal clicking and clacking noises which often change as the engine warms up or as oil pressure builds up.
Place a stethoscope directly over the suspect lifters on the Camshaft Cover. A Lifter that does not pressure up especially when cold and after not being started for a while would be a major suspect given only three starts since January and the cold temperatures.

Piston slap does not sound like that.

Worst case and unlikely given the minimal starts and low mileage.....You could have dropped a valve (bent a valve) and I would do a Compression Check on ALL cylinders as one of the first and easiest tests.
I would then follow up with a Bore Scope inspection of any suspicious cylinder just to take a look for any damage. My friend and mentor from up North suggested last time he heard that clatter was when a screw had been dropped into a cylinder and I was thinking a dropped/bent valve would be about the same.

Originally Posted by cmb

The last time I started it, I noticed a loud tick from under the passenger's side cam cover, toward the front of the engine. It's definitely a mechanical sound, i.e. not a noisy injector or exhaust leak. I changed the oil and filter and have let the engine run until it's warm, but the noise persists.
--Colin

Does the sound change when the engine is at operating temperature......the answer is yes as I see above.

It also appears the noise could be from the area of the passenger side Camshaft chain/Camshaft Chain Guides/Tensioner?
That would however, be unlikely with such a low mileage engine.

It appears this engine noise started all at once and you are sure the LT5 did not sound like this only a few days ago?
https://drive.google.com/file/d/0B83...ew?usp=sharing