smccloy

My engine is rattling when I accelerate, especially when I hit about 2,500-3,000 rpm. It sounds a bit like a chain. From what I can tell, the noise comes from the passenger side of the engine. I don't hear anything when I rev in neutral or when I maintain a constant speed. I took it to a mechanic, and they didn't hear anything. I drove away from the shop and heard it immediately. Today I faintly heard it when in park. I heard it my whole commute. At the end of my commute, I put it back in park and listened again but did hear it. To be fair, the engine mount blocks send vibrations after it runs a while, so the rattling might have just been masked on the other end of my commute when in park.

I have seen other threads mentioning 2,500-3,000 rpm, but most of them hear something when idling or in neutral. I do not.

My car is a 2009 Civic with about 180k miles. Everything on the car is stock, and it's an automatic. Some threads suggest a catalytic converter issue, but I replaced that a year ago.

Any thoughts? I'm taking it to a second mechanic, but I want to be armed with questions/things to ask them to look for. Thanks in advance.

FRSam

Has it ever had a valve adjustment?

smccloy

Not to my knowledge. I'll look into that. Thank you for your suggestion.

Forgive my ignorance, but if it's a valve lifter noise, should I expect to hear it while revving in neutral? Most videos on YouTube I'm finding of valve lifter noises on other cars are demonstrated in neutral while revving. I don't hear it when I rev in neutral. I really only hear it in drive.

sdaidoji

iTrader: (1)

did you drop anything when the hood was open?

smccloy

I didn't drop anything, and I looked around and didn't see anything foreign (e.g., leaf, plastic, etc.) in the engine bay.

Colin42

Check heat shields, on one of my 05s the lower bracket for the exhaust manifold broke and would make a horrible noise, took me forever to find it