Hello. I started my 2000 ML430 the other day and started to hear a loud ticking noise come from the engine bay. I checked the oil and it looks fine. When I rev the engine, the noise goes away at 2000rpm, but comes right back below that point. I took a video with my phone and will try to post it shortly. Any help or thoughts would be greatly appreciated. I still need to inspect the belts and pulleys. I was also told it could be my secondary air pump, but not really sure how to check that? Thanks in advance!!

Here's the video. The truck has 98k miles by the way, very well maintained, most components are still original.

Hate to say it but that sounds expensive..like a wrist pin bearing or something internal to the engine

any idea what might cause something like that? I'm gonna get it to my indy shop this week :-/

A 14 year old vehicle ??...who knows..wear, abuse, poor maintenance, simply mechanical failure..hard to say

I've had the car for the last 11 years and its been maintained to the tee. Fortunately, tonight I started the truck and the sound, while still there, was nearly gone. I had to drive about 30 miles and had no change in performance - still as smooth as it has always been. Going to take it in this week to get checked anyways. Hoping its minor. Thanks for the replies.

Update - heard back from my indy shop today. The oilers are the source of the noise and its nearly gone now. Not a problem and can leave it for now. Wheew!!

Have a similar noise on mine. What was the fix?