I'm stuck. My wife's neon has gotten the better of me. I got in to drive and there is an awful grinding noise on acceleration. I have checked the wheel bearings and all the bushings, all are in good condition. I have just replaced both CV axles because thats where the grinding is coming from. That was not the solution. The tranny fluid was a darker color, but still red, which from my experience means it could use a flush. Is there a gear set or a bearing in the transmission that may be causing this grinding? I thought it was the CV axles because there was a bit of play with them, but again, I was wrong. Is this the differential gear or bearing that may be my issue? Any help would be awesome, need to fix it asap.

 

Check the brakes to see if they are dragging. There could be something between the pads and rotor or they aren't fully disengaging.

 

does the noise change pitch when the trans shifts? like with engine speed? or does it stay one pitch through all gears?

 

@ Matix- It sounds like it gets harder/louder when I put my foot into it. Im thinking of putting it onto stands and putting it through the gears to try and determine. Wife says it goes away at freeway speed, but since I heard it, I've only gone around the block to see if the CV replacement worked. It's not the brakes, pulled those off and cleaned during the CV replacement. Sound seems to be in center of the engine bay.

 

i would drive it and toss in neutral while driving and see if it remains or stays to determine if if its a trans issue or something else. if it stays try pitching left and right to see if you can isolate it to a specific side. could be a loose shield or something .

 

Will have to try that. Could it be the transfer shaft or one of the cogs in that assembly? It only makes the noise during the acceleration, once my foots off the gas, the noise goes away. Sounds like a splined gear has worn down and is slipping. I think once I jack it up, put it into gear and gas it up, I may be able to hop under it to find the exact location. Really appreciate the input though. 2 heads are always better.

 

I work for a car place, and I've had both mechanics play with this thing (it's also an 03 Neon SXT, manual transmission). I've replaced motor mounts, half the front end, the struts, and things I've forgotten. The clutch is about a year old, and it doesn't seem to be that. We started out thinking it was the suspension because the car only does it under acceleration, not while coasting or at steady highway speeds. It also rattles over bumps. Braking doesn't affect it, revving the engine doesn't affect it, only accelerating affects it.

The sound is a loud roaring, grinding noise that is barely audible outside the car. I can feel a light thumping through the gas pedal and floorboard, and it sounds like it's coming from right in front of the steering wheel, or the wheel well.

Recently one mechanic lifted it and pushed the wheel up and down, and he says he thinks he hears something moving in the transmission when he does it. He thinks the transmission is going, but he's not the best mechanic I've ever met.

Anyway, if you find what's wrong, or if anyone else knows, let me know.

One more thing--this problem might have started when I was teaching my kid to drive a standard. She didn't want to learn, so she kept hard-killing it with the clutch. Very rough kills. A week or so later the noise started slightly, and grew worse.

 

It's a motor mount. There are four--two torque struts, one engine mount, and one transmission mount. I had replaced the two torque struts (plus the struts, any bushing that looked bad, and I forget what all), and each helped a little, but didn't solve the problem, and it slowly got worse again.

But there's a motor mount between the upper and lower torque struts (some people call these motor mounts, too). It's attached to the body just inside the passenger fender wall. If you look in the passenger front wheel well, to the front of the wheel, you'll see a plug. Pull this out (probably need a screwdriver or pliers), you'll see a bolt in the hole. Lift the engine (not the car) and look again. You should see a healthy bushing. If you see torn or cracked rubber, that's the problem. it sounds like the transmission (don't call them trannies!) or CV joints because the mount sags and causes the drivetrain to grind, I think.

My mechanic and I tested it but jamming a piece of rubber hose under the bolt where the bushing should be, and I drove it. First time in months it hasn't ground or made noise.

Hope this helps someone.

 

I agree that it is possibly a bad motor mount if everything else checks out. Mine was very bad, and after it was replaced, all sorts of noises went away!

 

My 2004 has just started doing this. I was clueless as to what the problem could be. I've just had some of my motor mounts replaced, evidently this one was missed. I was afraid that it might be a transmission problem. I've already invested a considerable amount of money in repairs. Hopefully, this one will not be too expensive!!!