94 Vtec

I got an intermittent extremely rapid rapping sound that comes on prior to the vehicle shifting, and goes away immediately as the car shifts. Oddly, sometimes the sound isnt there at all. The frequency of the sound is about the same as the valve train, like a machine gun, very quickly. Definately a metal sound, but not a light clicking like valves, not a buzzing, not high pitch, not low pitch but medium pitch, not subtle very noticeable. The sound is coming from the engine compartment. Also seems like a back and forth sound [like the solenoids do] OR an up and down sound, a very evenly spaced and balanced sound, except for being intermittent. Its not a grinding nosie, a screeching noise, a rubbing noice, a clunking noise. But if the sound could be slowed down in time frames, there would be silence in between each hit of the metal. Sound level increases as the vehicle approaches shifting gears and the rpms are increasing. Does the valve train solenoid make this sound? I never heard this sound on any other car before. Archives suggest a loose heat shield, but this is not that mid exhaust pipe sound that the tsb's emntioned. No CEL or blinking Trans light. But sometimes there is a stored TCM code. Do any failed valves with back and forth plungers or solenoids make this sound?

 

It might need a valve adjustment? Besides that your post is pretty vague. Take a video or something.

What is this valve train solenoid you are talking about? Im guessing the VTEC solenoid?

Lastly how would the Idle Control Valve have anything to do with a metallic grinding noise?


Maybe you threw a rod bearing? Does it sound like a farm tractor?

 

Valve adjustment, LOL, a really qualified Honda tech did that 3k miles ago, not a pseudo H-T.

Video? How does one video a sound? LOL you mean an Audio.

What is this valve train solenoid you are talking about? Im guessing the VTEC solenoid? Yup, when they fail or get stuck, does that cause such a sound?

Lastly how would the Idle Control Valve have anything to do with a metallic grinding noise? LOL, where did you read grinding noise?

No John Deere noises.

 

Sounds like you know more than anyone here. I'm sure you'll figure it out.

 

Dude, you want my honest opinion, a regular knocking sound that increases in intensity as the engine spins up. Sounds like a rod knock.

 

hey *******....he meant take a video of the vehicle acting up...in this day in age normally when you shoot a video it will have audio as well unless you have some sort of archaic technology...**** man my cell phone shoots 720p hd w/ GREAT audio. don't be so literal

what rpm is the vehicle acting up? is it all the time is the "noise" there when you are at idle?

your obviously very very qualified and smart...so you already assumed if it was a lose heat shield you get under the car and bang on them to see if you hear anything (with the vehicle cold as well wouldn't want to burn your precious hands but you knew that already)

Also to help ease with your concerns try to break your long over punctuated paragraph up into smaller easier to read paragraphs so it doesn't look like one huge mess of text

One more thing before i go if you can get the vehicle to make the noise while sitting still its quite easy to pop the hood and raise the engine rpm by hand to try to pinpoint the noise.

k thanks

 

Ok, but wouldn't that be constant rather than intermittent? I mean if it is a rod knock, why would it be a rod knock sometimes and not other times. Also, rods are internal and this has more of an external sound, or if it is internal, then it is coming from somewhere very close to the surface.

What about the torque converter. The sound disappears as soon as the car shifts, then comes back but again going into the next gear but again disappears after it shitfs.

 

Really, you think I'm that smart!? I'm sure I will figure it out sooner or later. LOL I've been compiling a list of some really great techs on H-T -- Duane, jimblake, P_Adams, mtnwkr and sometimes ghostaccord (for idle stuff). So, how long have you been a certified ASE tech and you do work for a Honda Dealership, is that correct?

 

No, I do not have that technology. My cell phone is a phone and does nothing else. AND I like it that way. I rarely even use it except on trips.

Noise ocurrs at various rpms, but only while moving-accelerating. Again, it stops after the car has shifted. Again, the noise is intermittent. Never at idle. Never while in Park or Neutral.

I know it isnt the heat shield. I'm familiar with that sound, as it has been a problem with other vehicles I have owned in the past.

Will do next time. Actually, I thought the post would stand a better chance of getting read, even if not completely, if it was a single paragraph. I see many instances in the archives where replies said the text was too long, and they were invariably several paragraphs most of the time. So, I made it look shorter.

What is your thoughts on it being the Torque Converter? What does a failing Honda Accord Vtec converter sound like? ... (please describe) ... is it intermittent or constant, any other symptom accompany it?

 

It wouldn't necessarily be all the time. If it is the beginning phases you might only hear it when cold or what have you. But a torque converter isn't going to create a knocking sound. If your Vtec went bad you would have a CEL and you would feel a loss of power when it normally kicks in.

The fact that this only occurs under load. Drain your oil and inspect it for metal, good easy check to make sure you don't have damaged stuff in your bottom end.

 

This sound has been there for awhile, it just comes and goes. Most noticeable in first gear right before the trans shifts to 2nd gear. No power loss or CEL. I just changed the oil two weeks ago and the sound was there long before that. No metal particles that I could feel or see on the drain plug tip. Engine purrs in idle, Park, Neutral. My understanding of noises from the crank, engine bearings, rods, etc., are a deep sound.

 

will it do it occur with the front up on jack stands with light load in drive? would make easier to diagnose since you can walk around and listen while someone is in the car acceleration.

an audio/video of the noise would be most useful as diagnosing noises over the net is quite a challenge with only a description to go off of.

a torque converter going bad on those 90% of the time they come apart and have the inside of it shot all through the trans and you get slippage and all kinds of other fun things as well. If it was going into lockup too early it would do it at 30-40 mph on light accel and that creates more of a judder like when you have a manual trans in 4th going 20mph

 

That's a very good idea. I will try that.

I dont have anything to record the noise.

As for trans slippage. When I put the car into D4, it wont move immediatley, have to wait 1-3 second min-max. Noise happens under 40mph at light throttle [I never throttle heavy]. Will have to pay more attention to the speed, rpms. I did a general search under "bad torque converter sound" on the www, and got to reading about broken flexplates, loose TC bolts, trans mounts, and on and on, no end to possibilties, contradictions, misinformation. But how common is it for the TC bolts in 94 vtecs to get loose? Can they be tightened without removing trans? There was some talk about taking an outer plate off to get to the TC bolts to check them.

 

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I'm fairly certain that I am able to eliminate the sound by shifting the AT manually from D1, D2, D3, D4. I will do this a several more times to be sure. But if that does eliminate the sound, then what, what does that indicate?