Car vibrating more when auto trans in Drive, less in neutral or park

[puzzledeagle]

My 1998 Mitsubishi Eclipse Spyder 4G64 2.4L engine with auto trans vibrates a lot more when I am stopped at a parking light and the trans is still on drive. However it gets noticeably more quiet when I shift it in neutral or park. What is the problem here? I am using conventional 5w30 oil, transmission fluid is normal and it also has new spark plugs too.

 

[Joethefallen23]

Sounds like it has poly engine mounts.

 

[T-Flexx]

Or the motor mounts are completely shot. Wife's ford focus is developing this issue.

 

[nelliott500]

Mounts are my guess as well. If it's vibrating a lot, I figure the mounts are shot. If it's just noticeable vibrations, it might be poly mounts.

 

[puzzledeagle]

Thanks for the advice. However what I don't get is why is it vibrating more on drive? When it's on neutral it's not that bad.

 

[GST Charade]

Thanks for the advice. However what I don't get is why is it vibrating more on drive? When it's on neutral it's not that bad.

its your mounts. it vibrates more when in drive because its under load.

 

[Warpathdsm98]

sounds like bad motor mounts. you can pop the hood put on the e-brake put it in drive and lightly press the gas. If you see excessive movement of the motor it's the mounts.

 

[DSM1G90]

Nobody asked the user on what the idle RPM is at when in D with the brake on.

4cyls and automatics hate each other since the tranny pulls a lot at low RPMS.

Might have to tic the idle set screw up a bit to ease up on the "idle shakes".

 

[puzzledeagle]

Nobody asked the user on what the idle RPM is at when in D with the brake on.

4cyls and automatics hate each other since the tranny pulls a lot at low RPMS.

Might have to tic the idle set screw up a bit to ease up on the "idle shakes".

It idles at around 1000rpm when in neutral, and around 700rpm on drive with my foot on the parking brake. So all I have to do is increase the idle set screw?

 

[McDizle]

It idles at around 1000rpm when in neutral, and around 700rpm on drive with my foot on the parking brake. So all I have to do is increase the idle set screw?

A normal idle is around 700-800 so if anything your idle at neutral is too high. What does it idle at in park?