[WHSNumba1]

Ok, just recently my car has started making this somewhat quiet knocking/clacking sound.

This only occurs with the engine in gear and while the engine is being placed under some kind of load, IE accelerating or engine braking. It's quiet enough that I cant really hear it unles i'm in first/second gear and accelerating below 3800rpm or so. If I coast on a smooth surface with it in gear, it wont clack until the engine starts slowing the car down or i accelerate again.

I know it's not valve tick because it doesnt do it in neutral, and I'm pretty sure the same goes for rod knock. Also, it seems to hollow of a sound to be a loud injector (plus it does it during decleration if the engine is slowing the car, and the injectors dont fire then)

So the only thing I can come up with is a loose or broken motor mount. I'm pretty sure I've had one for awhile (mostly due to a loud clack if I get on/of the gas really fast in 1st), but this sound is new, and once again is directly linked to the engine rpm and whether I'm accelerating/engine braking. All I can think of is that somethings wrong with a mount that the engine vibration is causing it to rattle around when i step on it.

Just looking for a second opinion as to what it could be. The worst possible scenario would of course be rod knock, but since it doesnt do it at idle or revving in nuetral, I think I can rule that out.

 

[WHSNumba1]

Also, I considered it could be actual knocking, but it seems like it started out of nowhere. Is there any way to rule out a bad tank of gas or some other kind of detonation?

 

[JDMugen]

I have had three motor mount problems. one in an Integra and the others in different cars. Doesn't sound like motor mount. The vibration and noise the come from it is Terrible.

Check out my post on the broken motor mount

 

[WHSNumba1]

Yeah, but it seems like it could be a less severe version of what happend to you. Especially with the sound the car will make if I stab the gas above 4000rpm in first (jolts the motor back and forth). If I do that, there will be a clack as the motor moves back and forth. I'm thinking it might just be getting worse to the point that it's vibrating around now.

 

[JDMugen]

When was the last time you had a valve lash performed? Have you listened inside the engine bay at idle, holding gas a different RPMs, and revs? Listen in all different spots, before tearing down or replacing parts. listen under the car, by the valve cover, and different sides. Sounds like rocker noise to me, too much gap

 

[RuPace12]

check your cat. converter heat shield

 

[JDMugen]

Also what year and trim is the car. What major repairs/maintence has been done with the car

 

[WHSNumba1]

I just adjusted the lash, and once again it doesnt do it when i rev the motor in nuetral so its not valves.

It's a 94 LS, and it's had everything done on the schdule. I do all the work on the car myself so I know it pretty much in and out. I'm almost 100% sure its not internal motor noise.

 

[integrascoot]

You're correct,it's not the motor making noise. it's your transmission. take it to the pro's at AAMCO or pull it yourself and check the bearings inside the housing. my tranny did exactly what you're describing but progressively got worse, much worse after a visit to the track. if i'm wrong, hell, shoot me. but its worth the preventative measures to check it out because a new tranny isn't cheap. good luck

 

[WHSNumba1]

You're correct,it's not the motor making noise. it's your transmission. take it to the pro's at AAMCO or pull it yourself and check the bearings inside the housing. my tranny did exactly what you're describing but progressively got worse, much worse after a visit to the track. if i'm wrong, hell, shoot me. but its worth the preventative measures to check it out because a new tranny isn't cheap. good luck

What exactly did it end up being? And how much did they charge for the repair?

The acura guy was shocked that my manual tranny was making noise and said if I had them do it, they'd just replace the whole thing rather than tear it down.

The aamco guy talked for about 5 minutes, then I mentioned it was a 5 speed and he went "what? really? huh we dont get many of those"

So all in all, i'd rather find out what it is wrong. If fixing it doesnt involve seperating the shafts or dissembling the gear clusters themselves, I'd probably do it myself.

 

[integrascoot]

In my situation, i think a bearing came out inside the tranny housing and got caught up in the gears, destroying everything, lots of fine metal shavings, not good. but it sounds like your case started the same as mine. I did the usual checking of heat shields, thought maybe a o2 sensor was rubbing, shafts were fine, so none of that. I changed tranny fluid and nothing came out indicating no problem, but because the big freakin magnet inside the tranny housing had collected all the metal in there i thought it was ok. i have an act clutch and experienced a few extremely rough launches and wheel hop in the rain so i think too much stress busted the bearings loose inside.(i'm not sure if you've possibly ever done this too?) It made the same noises you described only when the car was in gear, very subtle at first and hard to hear. after a while it became very audible and sounded like a mustang tranny to put in gear. i had some problems getting it in gear once it got worse, but it held up really well for how much damage the tranny actually suffered. i ended up buying a new lS trans. from acuraautomotiveparts.org for $1900, in retrospect i wouldve got a type r tranny but was rushed for time to get it running. i would recommend you pull the tranny and have a look.

 

[WHSNumba1]

Ok, but before I go and spend alot of my time tearing the car apart or alot of money for a new transmission, I'm just curious, could this be the throwout bearing?

Funnily enough, pretty much the exact same time this started my clutch pedal has been getting a little sticky in spots, which could just be completely coincidental. Maybe I'm just looking for another possibility, but looking at the exploded diagram of the 5 speed, I'm having a hard time seeing how a bearing could fall of a shaft without it somehow splitting in half right down the middle.

 

[WHSNumba1]

Something else just occured to me too, is there any way it could be an axle?

Would an axle make this sound only when under load?

 

[WHSNumba1]

Argh, so now I dont know what to think. I was driving around trying to figure this out, when I noticed that if I coast along at low speed, and shift into first from nuetral or second, I'll hear the clacking sound start as the synchro starts spinning up the input shaft. I guess theres a very remote chance that the weight of the input shaft spinning up could make the axle click if thats what it is, but i guess it's more likely it's something on the input shaft. I also guess its pretty unlikely that it's the throwout bearing doing this since it only does it when the input shaft is spinning. f**k f**k f**k, this is starting to look expensive. Anyone that's stripped down the transmission, how hard is it to pound the bearings on and of the shafts?

The thing that bothers me even more though is that it doesnt do it in neutral. A bearing should click whether the shaft is loaded or not, which is what made me think it might be an axle.

But if it's not a bearing... and it does it when I'm putting it into gear while the car is rolling, it must be 1: an axle with a weird problem
2: A synchro (ugh... $$$)
3: A gear (f**k $$$$$$)

Edit: one more thought: is it possible that the sideloading created by the gears trying to push each other apart could make a bearing click when the shaft is under load? Or am I just hoping for the cheapest answer possible?

 

[jojo]

If you need someone to test drive it to get a second opinion..PM me.

 

[WHSNumba1]

If you need someone to test drive it to get a second opinion..PM me.

Thanks man, but for now theres not too much to it, although who knows, if it comes down to it I might be able to use another pair of hands if I gotta rip the ***** apart

.Not many of my friends are much help when it comes to getting you're hands dirty.

Anyway, right now it doesnt seem to be getting worse, but that still isnt much consolation. In my mind I can just see a bearing freezing and spinning, which could make it impossible to replace it (damage to housing).

For the record, I only changed the fluid and filled it back up with Redline MTL a month or so ago, which made me wonder if that could have something to do with it. But the tranny shifts so smoothly with it (shifting is unaffected right now) and it has such a good rep I dont think it is related.

So pretty much i've figured out that I have a hollow clicking noise that matches engine RPM and only occurs when the input shaft is spinning (very quiet), and gets louder when the the shaft is under some kind of load (quite noticable from inside the car).

I really dont want to tear the car down in my garage because it's going to mean like a week of down time (school and work mean limited time). But at the same time I dont want to take it into the dealership, because like the guy said, they dont work on the trannies, they just slap on a rebuilt/new one. If thats how it is, I'd much rather have it apart in my own garage. To those that have removed the transmission, how much time does it take for a first timer? I'm not worried about difficulty so much as time constraints.

P.S. once agagin, I'm open to any more ideas anyone may have on the cause of this noise...

 

[dellaire]

don't know if this helps but, I had a tapping noise and I had just gotten an alternator pulley installed and thought it was making the tapping noise, then I though my cat heatshield, then my exhaust, when all it was, was a motor mount near my driver side wheel near the turn signal, had had the bolts fall out, don't know how, but replaced the bolts and the ticking went away, also if I would have just looked for the sound at first probably wound not have had to get new bolts, only looked when the sound got worse.

 

[WHSNumba1]

Alright, I'm pretty sure it's a bad input shaft bearing. It's looking like alot of work to get it out, but if I can rent some stuff I might go ahead and do it (i need a slide hammer and bearing puller).

Other than that all I need is a set of punches and 2-4 weeknights to pound this ***** out. I'm also going to look at how much it would be to have aamco or someone do this, because the dealership seemed pretty un-enthused about the whole thing ("why not just get a rebuilt transmission?" well jee, about 1200 dollars is why). The only thing that's really holding me back is downtime and the fact that I know I'm going to run into a few things along the way which are gonna make me want to throw a wrench at the side of my car.

So I guess what I'm looking for is some idea of how long it will take me to get the transmission of the car with basic tools. once it's of the car I'm not so worried, things are alot easier when you dont have to lie on you're back to do them...