funtogo

Hello everyone I wanted to throw this out here for discussion.I have a 2014 Mdx tech awd with 38,000 miles that I bought new.I really like the car and the way it drives.It has good power and I have no complaints.The other day I noticed a pretty loud knocking sound in the engine when in gear and warmed up between 500-1200 rpm.It doesn't do it when cold or in neutral.It was very noticable to me and I was concerned. It went away at normal speeds,or I just couldn't hear it.Took it in to see what it was and the tech said,after comparing it with another MDX and checking a few things that it was normal.I just wanted to see if anyone had heard the same knock in their car and what they did.

neoshi

Knocking or ticking?

funtogo

Definitely a knock!Louder than valves ticking!

funtogo

You have to put your foot on the brake while revving up a warm engine in drive or reverse to hear it!Or use emergency brake.Its a rod knocking like sound!

neoshi

Oh.. check your engine mounts then.

funtogo

Tech said they were good!

neoshi

Then you may want to check the suspension like control arms, cv joints, ball joints, etc for loose/worn components. Or even have an indie shop check it out because EVERYTHING IS NORMAL at Acura dealers 99% of the time...

funtogo

Yep!Thanks!

funtogo

Neoshi,would you check your mdx for this noise and reply back?Thanks!

Donn0128

Are you aure you have the right grade oil?

funtogo

I'm using 5w20.Shouldn't make a difference should it?Seems like it used a little with the 0w20!

Donn0128

That could be your problem.

funtogo

It's possible !

neoshi

If you could record your sound i can compare but just a description alone is too hard to say yes i have it. I've used both 5w20 and 0w20 and now 5w30 so it didn't be a difference really. If you've run low and your bearings are shot that would be another story but that tech said it was "normal" so i don't think it was bearings

funtogo

Might try to record it.

funtogo

I was driving the car up on ramps slowly for a oil change with my foot on the brakes and head out the window or I might not have heard it!

Edward'TLS

OP, does it sound like some pebbles rattling in a metal can ?

funtogo

No,it's more of a knock than a rattle .

Donn0128

Engine knock is generally one of only a couple of things. Piston slap of bad bearings.. bad bearings could be caused by any number of things including wrong grwde of oil. Piston slap is a sign of worn rings or very heavy block wear.

funtogo

I tried to upload a video of the noise but could not.Anyone have suggestions on how to do it?

DJ Iceman

Using regular rather than premium octane gas?

funtogo

No I use premium or mid grade mixed with it!

funtogo

This sound is heard in gear only!Do you hear these in neutral?

Bluepill

Based on the rpm and the warm engine condition, I would suspect the VCM system kicking in. Mine gets obnoxious at lower speeds after warm-up. It is worse if you have loose or missing clips on the plastic shroud over the radiator.