92 Accord EX, 4 cyl, 262k miles. Between one drive and the next, the engine runs very rough under 1500 rpm in park. Does not sound like its missing, just kind of puttering/shaking. Anything above that rpm in park and the engine runs very smooth. When driving it will accelerate but runs rough at any rpm. Either a vacuum or fuel filter problem? All vacuum hoses appear intact. The valve cover does have a small oil leak.

 

maybe the motor mounts?

 

so runs rough below 1500 rpm
runs rough all rpm while accelerating

can you tell me the vacuum reading of your car while idling?



i suspect that you have a mechanical problem since the mileage is too high as well. just an opinion

best thing to do is compression test, get the vacuum reading @ idle and let me know. i can help diagnose

 

It was the mount underneath the transaxle. Thanks for the clue...

It was the mount underneath the transaxle. Thanks for the help.