moonlitmusique

I've noticed that my MDX makes a rattling noise when I accelerate, and it happens mainly within the 1500 - 2000 RPM range. It starts as a drone, but when I apply more pressure on the pedal, it becomes a louder rattling noise. Once RPMs reach 2500 and higher, it disappears.
I can't reproduce the noise when parked, it only happens when there's a load (= car is moving). My MDX is only 30K+ miles, so this noise comes totally unexpected.

Has anyone else heard the same and how did you get it fixed? My local Acura Dealer gave me a BS explanation that the exhaust was damaged, but when I took it to a welder / exhaust specialist, they said there's no problem with it. I also took it to an independent technician, and he was able to hear the noise, but wasn't able to fix it. He said he tried tightening the exhaust heat shields etc. that are commonly the reason for rattling noises like this.

Thanks, any ideas and hints are greatly appreciated !

Donn0128

Engine knock, or more accurately preignition. Keep it up and you could detonate the motor into a million pieces. What fuel are you using? Try a couple tanks of 91 octane or higher fuel. If that does not do it, have the top end decarboned.

moonlitmusique

Thank you @Donn0128

Is that something that could take place in 2019 car that has been driven only 36k miles? As a matter of fact, I bought the car used at 22k miles and the rattle was already there, but dealerships and technicians so far haven’t been able to correctly identify the issue and fix it. God knows what the previous owner did with the car …

Anyway, I would expect that the engine getting carbonized (or the issue what you described), would be a problem for cars & engines with 100k miles and abusive driving?

Thank you !

Donn0128

Well, actually engines carboning up is generally due to short trips where the motor does not get a chance to fully warm up. Use of the wrong motor oil or lack of oil changes can also contribute.
My 2018 has less than 50K miles which is really low, but when we do drive it's 60MPH the 15 miles into town, so my motor gets fully warmed up. Look at your driving habits. Pull your dip stick and look. Do you see creamp foam?

moonlitmusique

Closing on this thread.

the Reason for the noise was a crushed muffler, once Acura dealer replaced the muffler, the noise disappeared. (Looks like previous owner backed over something and messed up the muffler.)