Slight engine vibration just before changing gears.

My 92 Accord automatic (170K miles) gets this short duration vibration just before it up shifts. It’s most noticeable when gently accelerating from 1800 to 2000 rpm’s in first. I can also feel it just before the 2-3 and 3-4 up shift at around 2400 rpm’s.

It almost sounds like a valve train noise like a loose rocker arm but everything is tight. I thought it might be transmission related but everything seams to work OK.

The honda dealer said that the slight hesitation is caused by a pluged EGR valve. I don't see any reason why I can't repair it myself but I don't know where it can be found on my 92EX auto?

I usually look at the Majestic Honda site microfiche but I think that Honda calls the EGR something else. Can anyone help me?

sounds like the hose that people replace with a breather filter. or the PCV valve. if its the PCV valve, just look for a little plastic piece by the valve cover that has a hose running to it and makes a 90 degree angle. take it out and shake it. if it rattles its good, if it doesnt, then its bad. i dont think it would make the car rattle when it shifts though.