Tlaloc75

I have an intermittent rattle that I can only hear when the car is idling and I'm outside the vehicle.

Here's a video, the sound starts at around 18 seconds and you can hear it off and on until the end:


Could this be a previously installed LWF? A failing DMF? Normal noises? Something else?

pp000830

Sounds like it may be failed lifter cartridges. How many miles on your car? Have you ever replaced the hydraulic lifters? In some ways, it sounds like slop in a timing chain too. If you get a piece of garden hose and use it as a stethoscope one should be able to isolate where the sound is coming from.

Also, check the idle speed as my experience is if the idle is too low the timing chain can make some noise.

Tlaloc75

Thanks for your thoughts. Engine has ~130k on it. Lifters were replaced at ~100k.

Idle speed is correct.

I believe its transmission related as I haven't heard the sound with the clutch depressed. Its hard to say for sure, since its an intermittent noise, but with the clutch pressed for about a minute I didn't hear it.

I have a slight rattle at shutdown, perhaps unrelated, that also will not reproduce if the clutch is in.

AOW162435

My junker has exhibited a slight rattle from the bell housing area at shutdown since I purchased it nearly 12 years ago. If I depress the clutch at shutdown, no sound.

This has never increased or changed in more than 30,000 miles.




Andreas

Tlaloc75

Do you have the rattle at idle as well?

jenskleis

Before assuming serious issues, check that the rattle is not caused by a loose screw on one of the heat shields beneath the engine or a screw tapping against the inside of a wheel arch. I have had both.

quacktoduck

do you have a light weight fly wheel? most lightweight flywheels will rattle at neutral but with clutch depressed will stop.

Tlaloc75

That's something I'm wondering too. I haven't installed one, but it's possible a previous owner did. I can also imagine that a failing dual mass flywheel would make the same rattle.

Any way to verify flywheel without pulling it?

AOW162435

No, just the normal gruff 993 idle sound.




Andreas

Tlaloc75

I've got that too! Just with a little extra cacophony .

Tlaloc75

Good suggestion, but I don't see anything loose there. Maybe something is loose inside the muffler or cats, but it doesn't have that sound to my ear. Sounds like something more substantial rattling.

quacktoduck

you can verify by the speed of how quick your car revs. or tearing into it. again very limited information about your car we are basically throwing darts on a wall

Tlaloc75

Would a video of the tach revving help? I'm not sure how else to capture how quick it revs.

Leander

My indeterminate rattle was caused by a degraded motor mount on the passenger side; the urethane was cracked and stretched.

Tlaloc75

Good suggestion, but I have fresh RS motor mounts, so I don't think that's it either.