Hey I was wondering if any of you guys knew what this sound might be? It sounds like lifters knocking but I don't think that's it. It only makes the sound after the rev drop under 2k rpm and as it drops from higher revs and idle. I've run synthetic in her since I bought her at 41k and she has 125k now. Last oil change I ran a can of chemtool through the crank and run her for 200 miles then changed the oil again with a 40 weight. Still the same, no change at all. So I changed the oil to a 5 weight to see if the lower viscosity would "degunk" whatever was the cause, still no change. I asked a mechanic friend of mine and he said it sounded like it was coming from the bottom end of the motor. Any ideas would be helpful please.

Thanks!

 

Oh and it does it hot or cold, louder when cold but the frequency is the same. I've also noticed very little power drop off. She runs great I'm just worried.

 

Same hear when the rev drops around 2k there's a rattle noise coming from under the engine

 

Maybe it is .... knocked up.

 

If it's knocked up, you might be getting a little baby G. My question is, who's the daddy.

 

Rods knock. Lifters tick. As you haven't supplied an audio sample its hard to determine. Search YouTube for rod knock / lifter tick and you'll hear the difference.