94 Accord 2.2L light engine knock @ 1750-2000 rpm?

[antiqueshell]

Just noticed this after finding a split plastic radiator tank top (just in front of the top rad hose (I think it is a seam area) I didn't lose much coolant and engine did NOT overheat, so I don't think it is directly related.

What happens is that when you rev the engine and hold between 1750-2000 rpm you hear a light knock sounds like its coming from near the middle of the engine block but not sure, as so as you have the rpms below or above that range you no longer hear the knock.

Engine has been well maintained never been low on oil, proper oil change intervals. 129k miles.

This sounds like a case for Tegger.

 

[Artem]

One of my buddies has the same Accord 2.2L. Same knocking sound at the same RPMs. His block has 230,000 miles though and has overheated several times in its life and has a bad headgasket, leaking coolant into the oil.

I say run the car until the engine takes a vacation. My guess is, its gonna be a while before that happens. Those blocks are practically bullet proof.

 

[yonyon]

Do you also get a noise like that going up hills?

 

[antiqueshell]

I actually have a hard time hearing it while there is a load on the engine, only seems apparent while in Neutral.

Although I don't have a habit of listening this closely, the car was in to the dealer for an oil change about 200 miles ago or so. Only put 200 miles or so on car since the OC ...I know I checked the engine this way about 8 months ago in a similar fashion and do not remember hearing this.

Also the rad leak just appeared, I hate to say it but I sometimes wonder if the dealer didn't "break it" somehow. I'm paranoid I suppose.

Oddly enough the car was into the same dealer about two years ago for an OC, about two weeks later the gas tank is leaking....hmmm. Coincidence?

 

[yonyon]

Does it matter whether or not the engine is warmed up?

 

[antiqueshell]

Appears to be noticeable whether cold or warm although a little less pronounced when warm.

 

[yonyon]

Maybe a little valve lash going on? That should sound more ticky than knocky though. Is it definitely a deep knocky sort of noise?

Engines transmit sound internally very well and oftentimes a sound can seem like its originating in one area, but that's just where the sound best transfers to the air. It is pretty common for a valvetrain noise to sound like it's in the oil pan or a rod knock to sound like it's coming from under a stamped valve cover. I've seen people replace accessory belts to try to correct a sound coming from a walking cam.

Is it loud enough that you can record it and post the recording? It could be that someone here will hear the sound and immediately know what it is.

 

[antiqueshell]

@yonyon:

Unfortunately I don't have access to a camera/ audio recorder right now...however the odd thing is that with complete certainty below 1750 and just above 2000 rpms the engine is dead quiet the noise is DEFINITELY not there. I'm tending to believe that the v tec system is at play somehow.

BTW the power delivery is fine and amazingly it seems to pull strong.

I'm almost wondering if it is a normal noise for this engine and I only got lucky hearing it this time because I was looking for problems. IDK.


One other observation, I noticed just after this noise I can hear what appears to be a single lower toned "click"
as I let the rpms drop.

 

[Mau]

the F22 is a noisy motor (we have a 96 Accord...noisy as [censored]!) but you may want to get a valve adjustment job done.

 

[mechtech2]

OK... We have a situation with a 20 year old car engine that makes noise.
Valve lash/adjustment is first on my list, and inspect the cams for irregular wear.

 

[tdpark]

Accords of that vintage were known to have a knock or rattle at around that RPM and that was due to the exhaust plumbing- apparently they had an anti-rattle kit you could put on your exhaust to get rid of it, I had a 96 accord and it did that. Middle of the engine is about where the sound would come from.

 

[artificialist]

I had a 1995 Honda Accord, and it always made that noise. The car ran fine anyway and lasted a long time.

 

[yonyon]

Now there's a nice bit of useful info.

 

[antiqueshell]

Originally Posted By: mechtech2
OK... We have a situation with a 20 year old car engine that makes noise.
Valve lash/adjustment is first on my list, and inspect the cams for irregular wear.


Well it's only 17 1/2 years old (bought in early 95).

And it was owned by my father since new, always carefully maintained and never abused, ever.

I'll have the valves adjusted.

@mechtech2: I am under the impression that it is safer for valves to be a bit looser (more clearance) than tigher, so in theory with increased mileage should the valves not be in danger of being with too little clearance?

 

[antiqueshell]

Originally Posted By: tdpark
Accords of that vintage were known to have a knock or rattle at around that RPM and that was due to the exhaust plumbing- apparently they had an anti-rattle kit you could put on your exhaust to get rid of it, I had a 96 accord and it did that. Middle of the engine is about where the sound would come from.



Nice hidden find!

Now this is interesting, neither my father nor I have ever heard of this. Do you have a source for the TSB?

I don't care about a noisy engine, as long as no damage results from whatever it is. Thanks!

 

[mva]

I had to change out the main exhaust pipe on my 94 Accord a few years ago due to noise.

If you do it stay with stock Honda parts. I tried non oem and ended up changing it again a few months later.

 

[RH+G]

The anti-rattle kit was a donut washer and sum bolts and spring. The rattle was from the area where the cat and header meet under the car. Dont thinka dealer would even have this any more

 

[Tegger]

Originally Posted By: antiqueshell
Just noticed this after finding a split plastic radiator tank top (just in front of the top rad hose (I think it is a seam area) I didn't lose much coolant and engine did NOT overheat, so I don't think it is directly related.

What happens is that when you rev the engine and hold between 1750-2000 rpm you hear a light knock sounds like its coming from near the middle of the engine block but not sure, as so as you have the rpms below or above that range you no longer hear the knock.

Engine has been well maintained never been low on oil, proper oil change intervals. 129k miles.


A car this old, living in the North-East, it could be anything.

Corrosion does bad things and causes many odd noises. Sounds have an annoying tendency to carry, so where you think you're hearing it may not actually be where it's coming from. My first thought is to put the car on a hoist and check the entire exhaust system for rusted-loose heat-shields.

Your report of the noise being very specific to a particular rev-range definitely suggests loose parts, whether they're exhaust-related, corrosion-related, or something else. Loose bolts can cause such odd noises. Your year Accord has no TSBs related to knock-type noises, so I think this is a case particular to your car.

And as mechtech2 says, check the valve clearances. Valve noise tends to manifest more at idle than above that, but it doesn't hurt to check. Also check the ignition timing, just to make sure it's not advanced from where it should be.

 

[antiqueshell]

@Tegger:

Your advice is second to none I have the car going in for a new radiator this in a week (have my VW Golf as a trusty primary car) and I will have the mechanic look at the exhaust system, check valve clearances, and timing, you always seem to be on the money.

Thanks as always, and have a good day...eh.

I bought this car from my Dad and at first I was lukewarm to it, but after driving it have grown to actually appreciate it, the only thing it is missing is a manual transmission.