My 08' Fit makes the same knocking sound in this video. The knocking disappears as soon as you press the gas; especially in the cold start. What do you guys think? Thanks

 

Piston slap noise usually acts this way. However no guarantee that this is the case

 

Ah, the famous GD knock. I had that.

 

Did you fix it?

 

It is not necessary according to the "Honda experts" (read: the new block/pistons will knock after 20 to 30 k miles
The power of incompetent engineering
http://jaygl.org/wp-content/uploads/...vich-412-6.jpg
In the past mainly Russian cars did it

 

I recently found that the knocking noise disappear when the AC kicks in and when I revs my engine at 1500rpm. What do you guys think it could be?

 

Take drive belt off (from COLD engine) and run it at idle (P or N) for few seconds;if no noise it may come from belt driven accessories (although almost everybody are say it is piston slap!)

 

Mine makes the same exact noise... Would a valve adjustment be a solution for this?

 

Valves sound differently than on video
Take the belt out (as above).
If noise stays it is piston slap
At medium RPM or under load the pistons are exerting more pressure upon cylinder wall during the travel so noise tend to disappear.

 

Will try to get some help from a buddy to get this done.

Also, I have went to a shop and listened to the engine via stethoscope and noise was coming mainly from the fuel injection area rather than the top of the block... Any takes on this?

 

I tried to listen with a stethoscope near fuel injection, I couldn't pin point the location since the noisy fuel injectors; seems like its somewhere in that location. Did you adjust your valves yet? I did mines, although the sound is still there.

 

Haven't adjusted the valves yet but going to try and get another diagnosis. Sounds have been getting louder at low RPMs as each day goes on. Not too mechanically inclined so I just try to read around as much as I can and go from there.

 

Piston slap

 

No.

I did all the listening and stethoscopes and asking mechanics, but it got me nowhere, so I decided to beat on the engine even more than I was, and just drive the h*ll out of it, to see of I could break it, but that didn't work. Finally, I gave up and lived with it until I sold the car.

Doctor J may very well be right with regard to piston slap. However, if it were piston slap, you would think that someone would have some real evidence to prove it by now.

 

Interesting... I drive the hell out of my car as well. I commute at least 150 miles a week just driving to and from work and often drive the car hard as hell on the freeway. Still get good MPG, acceleration seems to be good, burns oil sometimes but nothing drastic and often. This could just be an annoying noise that does absolutely nothing at all, but it does bother me.

Just curious, could anyone shed some light on making a "piston slap" disappear or if that's even possible? This noise was beating at quite a slow rate when I first got the car (118k), now that i'm nearing (125k) it's been beating at a higher rate and sometimes it's evident during acceleration (3-4k). Once I get the car to speed around 40+ it does disappear but once i'm stopped and idling you'll hear the loud tapping at a very fast rate....

 

I could only guess that there not many engines are opened due to the failures, so someone could measure the piston and cylinder. Also at present time "rebuilding engine in the garage" is VERY uncommon (replaced by swap or exchange); this why I can't find well written report about specific wear responsible for this sound.
Here are my guesses:
The engine by design has offset crankshaft (by 23 mm off the cylinder deck center line) to minimize engine vibration so the pistons are wearing more on one side
The engine block is aluminum (with cast in steel cylinder liners) somehow it acoustically amplifies sound affect after some normal piston wear
Sorry if it sounds to scientific
Some Russian (rather Soviet made) "masterpieces" of mid 1970-s which used simplified BMW slant-4 aluminum engine concept with wet liners produced same noise due to wide tolerances and poor assembly quality.

 

I had exactly the same issue. Valve adjust did not fix it. I kept it like that for 50K miles, no issue so far. What really killed my 07 Fit AT sport, was cracks on the strut towers. check my post about it here:

https://www.fitfreak.net/forums/1st-...uts-mount.html

Can you check your car to see if the problem is not isolated to my car? thank you.

 

You can try unplugging one coil at a time to see if the noise goes away. If it does it could be rod knock.