I have a 2000 Subaru Legacy Wagon and have had it for a year now. I notice that every once and a while the #2 piston misfires, I bought a computer that tells you what is wrong when the check engine light comes on, the car if I try to accelerate fast will buckle and hesitate very bad, so to correct this I change the spark plug wire and it works fine. The spark plugs are brand new, Bosch, but I wonder if something else is the problem because only #2 piston misfires?
HELP John
Interestingly, my 99 Subaru Forrester hesitates and bucks ONLY when it's extremely humid out, especially during heavy rain. This happens even when it's parked out of the rain! Wonder if changing the spark plug wires might help!
"Jerseyj" wrote
Take a good look under the hood in the dark. It can be quite revealing if there's arcing going on.
-rick-
Putting your fingers near the plug wires while it's running can be interesting too. Don't necessarily have to get that close (depending on wire condition).
too. Don't necessarily have to
Hmmmm, I did not know piston fires. LOL! Tony
John - I had a code indicate a piston misfire too (same piston coincidentally). See my comments below that I copied from another response about how it was diagnosed and corrected....
Re: 97 Outback: vibrations when idle in D by "JWC" Apr 19, 2004 at 09:02 AM
I drive a 98 Legacy Outback. My car was having similar problems. Idling at a traffic light in drive the car would vibrate or rock pretty substantially. If I pressed the gas slightly, the vibration would lessen.
Though this was pretty annoying, I didn't think too much of it. When my 'Check Engine' light came on, I took the car to the shop thinking it was an emissions sensor that would need to be fixed/replaced. They told me the Check Engine code indicated that I had a misfire in one of my cylinders. At first they suspected a burnt valve, but further investigation found that all I needed was a valve adjustment (with new shims or seats, I think that's what they were called). Apparently the valve wouldn't seat properly and this prevented the cylinder from achieving the necessary compression, and with the periodic misfire, I was more or less driving on 3 cylinders instead of 4. After having this fixed my car doesn't vibrate any more. The bill came to a little under $700 (at the Subaru dealer) which also included adjustments for the other valves while they had the engine apart.
What mileage was this at?
This was at about 102K miles
thanks
My manual calls for a valve adjustment at 100,000 miles, and I was wondering if this is really necessary.
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