I have a 2006 coupe and when I was driving earlier it wouldn't go past 2500RPM, and instead just started shaking. Also for a couple days when I have tried to start it it sometimes produces a grinding sound. I'm thinking somethings wrong with the transmission.

 

More detail? At, Mt, mileage, bolt ons etc would all help the diagnosis my friend

 

Its got 140K miles and everything except the rims and suspension is stock.

 

Will it go pass 2500 in neutral without shaking?

 

No. It was still shaking in neutral as well.

 

It can't be the tranny then. Is check engine light on? And is there any kind of noise when it's shaking?

 

No noise, and no light. I don't wanna go to an auto shop to have it diagnosed, but I can't figure it out.

 

Is it shaking or grinding? Is it the engine sputtering like it can't throttle up or is it an actual shake / grind?

 

Post a video under the hood

 

it only grinds when i try to start it up, and the whole car shook, but the engine didnt really sound any different.

 

Grinding when trying to start maybe starter not engaging all the way. Whole car shaking idk that's why post a video it will help more.

 

If the same problem exists in Neutral... Then I might lean towards exhaust/catalytic converter/air flow issues possibly??

Not sure if it applies to the G (obviously hasn't happened to me in my car).. But I have a '94 Dodge Ram as well, and your exact symptoms happened when the catalytic converter welded together internally, and air flow wasn't going out the back, but instead back up in to the engine.. Caused all sorts of problems (no RPMs past ~2200, major engine block shake, etc etc.)

Just my .02, and again might not apply.

 

Anyone consider the obvious choice...motor mounts? Harmonic balancer or even pilot bearing, pressure plate are all possibilities, however a cracked motor mount any ANY rpm will cause a car to shake in any gear like a troubled child on crack. Believe me, I had the opposite problem, I had shake due to solid motor mounts. At 140K a car's motor mounts might eventually give in, and even one cracked on will cause it to go. I made my own mounts in the past.

vegas, check the mounts and then get back to us. If it's not visibly cracked then you might have a mechanical issue on your hand not a bad motor mount. A video would be helpful but lets start here first.

Put up a video of exactly what you are experiencing.

 

Check your throttle boddies.

Any check engine light?

 

You might be onto something. Answer me this Vegas. Did you wash the engine bay? Plug a scanner in and let us know if there's pending codes. The CEL has to occur twice in a drive cycle to cause the malfunction lamp to go on. Erratic conditions like the f'd up idle can sometimes not show up.

Pardon my stupidity but did you install a CAI recently? Did you do the MAF install correctly? As for the washing thing. I forgot that in this one guys Honda I worked on he had a similar issue. Turned out to be water in the dizzy. Don't rule that out. Inexpensive fixes are cleaning the MAF and shaking out and blowing compressed air through the bay to get any and all moisture out. Sorry I can't be more helpful.