Rough Idle in drive but not in neutral
 

Good day everyone! I have recently purchased a used 2004 honda accord. It is great but for some reason it idles quite rough in drive. Enough to really get on my nerves. I have new o2 sensors and new plugs. i also replaced the multiplex (causing other issues, i dont think it pertains to this but just wanted to mention it) and had an oil change and the fuel injectors cleaned. Any help would be great. Thank you!

Possible bad motor mounts:

https://www.hondaaccordforum.com/for...shaking-51983/

Ohhh. okay. Is there anyway to know for sure before replacing them?

Does it idle rough when the car is stopped and in D?

Yes. but not in any other gear. only drive. It doesnt do it in reverse either. atleast ive never noticed it.

Have an assistant put the car from P to D while the hood is open. Watch the engine for excessive movement.

I think the front mount is vacuum activated on this generation accord. Check that the vacuum hose is connected to the mount and that the hose is not damaged.

The vacuum hose for that mount goes to a solenoid valve. Get someone you trust to help.
1. Engine all warmed up, idling.
2. Shift into DRIVE & hold the brake.
3. Unplug the wire from that solenoid valve on the mount's vacuum hose.
4. That SHOULD cause a big change in vibration (worse).
5. Same test using REVERSE instead of DRIVE.

You can also use a MityVac or something like that to see if the mount itself holds vacuum.

I was having a similar problem and I check the transmission fluid and it was quite low. I filled it back up and sure enough I havnet had a problem. A quick and easy fix worth looking into.

Any idea is good to check out!

But then we have to ask "why" the fluid was low :)

Where is HondaDude when you need him.......