Why do you say thrust bearing is absurd? Its exactly where the sound is coming from.

You have multiple cylinders firing and each one is its own event so you could have one or more cylinders making less power. Plus it could be knock in a cylinder or two causing the crankshaft to hit the thrust bearing. That is why I have spent so much time talking about octane and proper burn in each cycle which is less stressful for the engine. You want each event to happen at the right time and premium helps insure that.

Oil type and mileage on the oil is the other variable. A clean motor will make more noise because the parts are free to move in their clearances. Problems start happening when parts stick but that does not mean the motor is ruin in itself but wear could happen.

 

Sorry I didn't mean bottom end, I meant block...

 

Same difference, the thrust bearing is in the block. Try premium and see if it goes away. Other wise its normal if there is no other symptoms.

 

Registered so I can add my two cents on this.

I call this noise Honda rattle. I have had two cars that do it including, unfortunately, my newly acquired 2008 Certified Fit. Did not notice it at all during the short test drive or once over.. sounded nice a quiet.. a few days later... I heard.. IT!

This diesel sounding monstrosity was my 2000 Honda Accord 2.4L 5 speed
Kerplunkety - YouTube

Very distinct knock at idle.. and a rattle at between 2300 - 3200 rpm or so.. noisest under no load or engine breaking coming to a stop ( 5 speed )

Drove me NUTS.. even replaced all the bottom end bearings.. Rods, mains, thrust... Didnt change the noise at all. Valve lash checked and rechecked and then checked again..

My conclusion... wristpin noise.. possible piston slap.

Fix... sold the car.

Got a 2003 Accord EXL V6, Automatic (ugh)... whisper quiet.
Transmission.. horrible.. replaced once by honda.. out of warranty was showing signs of going again..

Fix... sold the car.

2008 Honda Fit Sport 5 speed
Honda rattle - YouTube

Not even half as bad as the OP.. more like the second posters video under the hood.. Maybe my ears are just tuned to it... I dunno.

The strange thing about both these cars is their mid range power was not smooth at all.. The Accord and this Fit both surge at 50% + throttle in the mid rpm range.. 2500 - 4000.

My conclusion on that... call me insane if you will... the knock sensor is picking up this rhythmic tap/knock and mistaking it for slight detonation is pulling timing sporadically.

Another similarity... below average MPG. Granted this is my first tank of gas.. they filled it at the dealer.. but I only got 238 miles? What?

Something isnt right... Which brought me here!

Anyway... Hello everyone... sorry my first post was such a downer! lol

 

accords are known slappers but I'm not sure about that particular year. From what I've read it doesn't seem to affect reliability so I'm curious why you would rebuild it.

Also, I need something clarified from silver bullet. Doesn't octane related knock pretty much only happen under load.

 

The v6's were prone to wrist pin noise.. mine was quiet though. The 2.4 drove me nuts. I have what I like to call 'mechanical OCD' and unexplained noises aggravate it into an obsession... That's how come the accord was rebuilt.. I think the OP knows exactly what I mean.

Which is why hearing a slight Honda rattle in this Fit is making me anxious.

 

Believe me, I understand the anxiety that goes along with spending thousands of dollars on a car and having an engine noise that will draw attention from pedestrians. Take comfort in the fact that my car has been doing this for a long time and now has 115K on it and is frequently brought up to redline. I'm not going to sell it because because it's paid for and finding a used fit for what mine's worth that has all of the mantainence up to date would be next to impossible. If the engine blows up, I guess it's time for a used motor from ebay.

 

Its good to hear others have the same noise quite frankly, and of the videos I found on youtube with the exact same noise as mine have comments like "Thats normal", "Mines always been like that..".. I am not too much worried.

My car is not too bad... only I can hear it lol. Just have to see if it gets worse.. I have a feeling it wont. The car has 78k miles on it already.. Warranty up to 100k.. Its just a wear characteristic of the engines... Some get the worse end of the stick though.

On the accord I did the bottom end with the block still in the car and the head on.. just removed the oil pan. So I didnt get to pull the pistons and inspect the wrist pins. Always wished I would have pulled the head and did new pistons and rods also... Then I would have known definitively what it was. Or have been twice as frustrated... something.

 

Well as a follow up.. The noise my car is making has gotten significantly worse. I have an appointment with the dealer tomorrow... at.. 6:50AM??!! That's the only time they have available "for someone to speak with me about the car"

New video
2008 Honda Fit Engine noise - YouTube

I JUST purchased this car not but 2 weeks ago. Certified used. The longer I drive it the louder it gets. Of course that's only been 500 miles or so but I can now hear it in the cabin if I am stopped at a light.

Hopefully this will be resolved. Though quite frankly I think its going to take at least a new short block to fix it..

I can hear the injectors ticking
I can hear the valves tapping slightly
I can hear the timing chain whurring
I can even hear some slop in the bores when the engine is cold..

none of that bothers me...

but THAT.. sir.. that is a knock... a tiny little rod knock from a tiny little rod. It needs fixed.

 

Load is a subjective term and is used to refer to an equation that is determining cylinder pressure in some applications and is used to describe "mass of atmospheric gasses per revolution per cylinder"

If you are asking if it should knock under idle the answer is "no" provided everything is timed right mechanically and electronically. Is it possible to knock at idle? Yes. Is it likely, no. Every engine is different.

Knock can happen almost anywhere in the rev-range. Context/details are key to a question like that.

 

I guess I am a octane junkie. Octane Boosters Testing - Tech Review - European Car Magazine

 

Well that was so much easier then I thought. Dropped the car off at the dealer this morning. 7 hours later I got a call.. they are replacing the engine. Slop in the #2 wrist pin. Gave me a 2012 Accord EX-L off the lot to drive.

This was a Honda Certified car and the work is being done under warranty, though strangely enough the service manager said they are going to put a used engine in it. Less then 10k miles on it he said.. I would have thought any short or long block replacements would be Honda manufactured.. not used. I am not complaining... just seems strange. and where do you get a 1st gen l15a with less then 10k miles?

Scary thing is... my fit was making the same noise as others are complaining about. and at 79k miles this 2008 reached maturity a little sooner than most.. are we going to see an epidemic of knocking Fits as they start reaching the 100k mile mark?

 

Veeerrrry interesting Spdweb. Mine is in about the same window as yours minus the knock... model yr and mileage... Knock on wood... Engines less than 10k? Probably from totaled Fits graveyard... As long as they cover it...

 

If you don't have it by now I would say your fine. It seems to be a wear characteristic. Some engines get it some don't. I have heard people complaining about 30k mile Fits knocking in my search for answers.

The replacement engine takes on the remainder of the 100k cert warranty so.. its all good! Most of the time any problems are immediately noticeable with used engines. I guess it could knock just the same though lol

 

I don't like hearing all this. Mine has been making an odd knock sound since about 2,000 kms. It also makes kind of a rattle around 3,000 rpm. It has 80,000 kms on it at the moment.

 

I have gotten use to the rattle.. just about all the 4 cyl Hondas I have owned ( 6 of them ) have a rattle somewhere in the mid RPM range under no load or very light load. Worse when the engine is cold. I attribute it to short piston skirts. Even the brand new 2012 Accord the dealer gave me to drive does it. It only had 150 miles on it. Sounds awful during a cold start.

The knock that everyone seems to be describing, at least in my case was diagnosed as a bad wrist pin. This also seems to be a problem with certain Honda engines... why they have problems with wrist pins I don't know. The only thing I can think of is lack of proper oiling. They are only oiled by "fling". Oil is thrown off the crankshaft and scrapped off the cyl wall by the lower oil ring. Some of this oil finds its way into the wrist pin.

Excessive idling, or running out of oil.. the wrist pins usually suffer first.

The 'good' news is that neither a loose wrist pin or sloppy pistons are really detrimental to an engine. They just sound like crap and make my OCD act up.

 

L15A1 and L15A7 both have oil jets bored into an adjacent galley spraying onto the wrist pin and under the piston dome.

 

OOOP.. Thats why you never assume things... lesson learned lol

 

The knocking noise that my car makes at idle as well as the others with similar noises who have provided youtube videos is in my opinion not the same noise as the no load 3000rpm noise that every honda I've owned has made. Maybe I should say it a different way. I don't think an engine has to have both noises in order to have one.

 

I would say that's exactly right. We'll have to see how this new engine sounds if I ever get the car back from the dealer. I bet it will have the rattle... but hopefully not the knock. At least for some thousands of miles anyway. I wonder if anything can be done to prevent it.