I have an 02 Accord with the 2.3 F23A4 engine. The engine was quiet when I first got the car but about 30k miles later at around (190k) it started to sound like it was making a loud knocking noise when it was cold or at a certain rpm when letting off the throttle. I wasn't overly concerned about it as I always maintained the proper oil level. I was just going to keep an eye on it to see if it gets worse. The car now has 227k on it and it still makes the same noise maybe slightly worse. It's more noticeable in the cold weather than the summer. Also when it's really cold out and I start it the engine is quiet for a couple minutes then it starts to make the noise again. Is it possible for the engine to be knocking for almost 40k miles or is this probably piston slap? The valves were just adjusted and the sound didn't get better or worse.
Question on piston slap/rod knock
- Thread starter joegreen
- Start date
sounds like big end bearing knock from your description except it usually doesn't take long for an engine to die from that condition.
They’re noisy engines that’s for sure. I had one for 10 yrs/170k miles but it still ran like a top when I sold it. Does it consume any oil, what oil and weight are you using? Magnatec or Pennzoil 10w30 should help quiet the engine if you’re not already using one of those. M1 is a little noisy but keeps things super clean.
I am using she'll rotella t5 10w30. I bought a whole bunch a few years ago when AutoZone was having some super sale. It does consume oil but I do not know the rate as I never cared much. Plus it had a few oil leaks which would cause inaccurate consumption rate.
The transmission is not very good on the car so I start out in second a lot of the time which means it gets floored a lot when taking off to keep up with traffic. I'm sure the high load low rpm would have done in any bad bearings by now but maybe not.
A rod won't knock long (A few miles) before it quits. Has to be a Piston or Main bearing.
Have you ruled out the timing belt components?
" It's more noticeable in the cold weather" " I am using she'll rotella t5 10w30"
Have you tried a thinner oil?
" It does consume oil"
Top off with MMO see if that lessens the noise.
" It's more noticeable in the cold weather" " I am using she'll rotella t5 10w30"
Have you tried a thinner oil?
" It does consume oil"
Top off with MMO see if that lessens the noise.
OVERKILL
$100 Site Donor 2021
Typically rod knock, if it was rod knock, which it doesn't sound like, gets worse as the engine warms and the oil thins. Piston slap on the other hand usually starts out pretty loud and quiets as the pistons expand. The fact it doesn't do it immediately makes it not seem like it would be piston slap, maybe a wrist pin?
Any chance of grabbing a recording of it?
Any chance of grabbing a recording of it?
I will get a recording. The noise is basically always there and always sounds the same. If I can recall it gets a little louder when revving slightly above idle.
I changed the timing belt at 212k and nothing changed sound wise. I have not tried a thinner oil.
Mine did the exact same thing (was quiet then started making the sound you described). It ran over 60K like this. I took it apart after it died and found the main bearings destoyed. An old time mechanic said it was this right when it started. If I were you I would drive it until it fails.
Do a mechanical oil pressure test cold and operating temp at idle and 2500 rpm. Worn bearings will show the wear with this simple test.
It could even be a cam bearing surface wear.
It could even be a cam bearing surface wear.
Ok. I actually do have an oil pressure test set I have never used. I'll have to find out where there is a port I can tap into.
This may help..
Awesome thanks. I know right where that location is
OVERKILL
$100 Site Donor 2021
I'd probably just put it on youtube, unlisted, and embed it here.
That’s precisely the same noise my old F22B2 Accord has made for 10 years and 150,000 miles. I have no idea what makes the noise, but I do know for a fact it is not in the head and it is not the balance shafts. If you find out what it is I would love to know, I am convinced it is in the block somewhere.
OVERKILL
$100 Site Donor 2021
So it's pretty pronounced right off the bat then eh? Does it get louder at all when it warms or is it always just about that level? I'm thinking wrist pin still maybe, but definitely check what Trav said first. Also, have you tried it with the belt removed to eliminate it being from any of the accessories? Always a good troubleshooting step "just in case".
