Hey everyone, I have a 2018 Fit EX 6 speed manual that I picked up earlier this year. It has ~98k miles and seems to be in overall good condition. However, it does make a concerning rattling sound under load around 2k rpm. It is most prominent with decent throttle input in third gear. I don’t hear it at all in first, and sometimes just a little bit in second. If I’m very light on the throttle it will accelerate through the problem rpm range without making any noise. It’s especially loud when I’m going up a hill and have to give it some gas to maintain speed. I have checked for heat shields, fresh engine and gear oil changes, and new spark plugs and coils. It doesn’t really feel any different when it’s making the sound but it definitely doesn’t sound good. Has anyone else experienced something like this?

 

Couple other vibration-related ideas:
1) Check your exhaust system for a loose or broken hanger.
2) Check to make sure you don't have any gravel wedged above a heat shield or the muffler.
3) If you have the capability to raise the front wheels off the ground with a lift or sturdy jack stands I would see if the rattling changes. Does it still occur at the same rpm range?

 

Is it an engine rattle or a "something's loose" rattle? Pre-ignition? Pinging? If so, that's very harmful.

 

I will try to take an audio recording soon. Sounds like it could be a heat shield to me but I’m not sure. I wasn’t able to see anything that would be making noise down there but I don’t have a ton of experience working on cars.

 

I had the heat shield on my catalytic come loose. I bought a new one online. One of these days, I'll replace it. Metallic rattling noise.

 

1) An additional pair of eyes & ears helps a lot in these situations.
2) A bad engine/transmission mount can let the engine shake such that something may hit something stationary (just enough for an exhaust system to touch another part, for example) and nothing has to be loose!
3) Do you have a jack and stands?

 

Here you go! 😂

That picture is hard to look at.

 

I have 2015 Fit EX manual and have the same issue. It started around the same time as your car before. Mine now at 107,000 miles and still have the issue. I can only hear the sound in 3rd gear and it doesn't do it in the other gears at all. Run fine still. Also, in 3rd gear, it will only make the sound at 2K RPM and will stop once you hit 2.5 or above.

I think it's inside the engine and I think it's actually the carbon buildup on the valves. That's my guess though, I don't know for sure. But, I have been using the GDI cleaner sprays and it seems to make the noise less. It's NOT gone, but it's less.

I think if you go to a shop and get the manual cleaning out the valves it might solved the issue. The service isn't cheap though. Maybe a few hundred or more.

 

I get that rattling too in first gear while under load (manual) and it definitely sounds internal as opposed to a heat shield-type of noise. I believe it's spark knock, but I don't hear it in any other gear. It runs great otherwise and maybe it's normal or the knock sensor is slow to react, but I'm not too concerned.

 

Do any CVT cars have this noise?

 

That's only on startup and for a very short amount of time.

 

Well...we are talking about engine noise so in theory I would say yes. Having said that, an automatic transmission is good at smoothing things out and "knows" when to shift optimally. I don't like to slip the clutch when starting off which is when I hear the noise; an automatic doesn't load the engine like my (poor) strategy does. Bottom line,the noise is a big nothing burger.