Idling rough when in gear

[bullguy]

I could use a little help. My TB is vibrating and idling rough when in gear (drive, or reverse.) The RPMs are okay as soon as I hit the gas it runs just fine. It also idles just fine when in Neutral, or park. I thought it could be the engine mounts, yet it only idles rough when in gear, like when I am stopped at a stop light. Any ideas or suggestions (Hope Rodie will help )

 

[Matt]

It's the motor mounts. There's a number of threads on this forum if you use the search feature, but here's Roadies reply to one of them:

If the RPMs stay constant, and the vibration is exactly 10 Hz, it's motor mounts. If it reduces with higher temperature, it's confirmed. I recommend looking at the plastic intake manifold housing on the driver's side and see if you see the rotational vibrations worse there, about 1/4" or more, that's another clue. Some folks have tried to pry up on the passenger side motor mount (usually the one in worse shape because of the nearby exhaust manifold) with a pry bar and if the vibration changes its nature, that's positive confirmation.

Always have somebody you trust on the brakes while you do an underhood experiments in DRIVE with the brakes on.

 

[Mooseman]

Clean the throttle body and disconnect the battery for 30 minutes.

 

[bullguy]

Clean the throttle body and disconnect the battery for 30 minutes.

I tried that but no difference

 

[bullguy]

It's the motor mounts. There's a number of threads on this forum if you use the search feature, but here's Roadies reply to one of them:

Thank you,i will check and update

 

[mrrsm]

In keeping with @Matt 's suggestion... This APP along with their proprietary Blue Tooth Device shown in this Training Video works in combination with your Cellular Smart Phone on a variety of vehicles for the accurate diagnosis and measurement of a lot of different frequencies and amplitudes for vehicle components... either singly or in combination to pin down "What's Shaking" either on or inside of the Engine and the Vehicle:

...and here is a video showing the NVH APP in action for a Road Test Drive Diagnostics:

Alternatively... there are other dedicated Vibration Analyzers available that are quite expensive.... but this offer from Aliexpress.com seems very reasonable for the price:

https://www.aliexpress.com/item/Dig...arch0204.8.8.65523d661tP5SW&priceBeautifyAB=0

 

[Capote]

Have you checked for any vacuum leaks? Are there any lean codes? Sometimes you'll have a pending code that doesn't trip a CEL just yet.

 

[Mooseman]

Worth a shot to check fuel trims and other data before condemning the motor mounts but they can be responsible for that 10Hz vibe at idle.

 

[bullguy]

Dear All,
Thanks for your kind support, the problem is due to Bad Motor mount