I've got a 1999 Mazda 626 that shakes really badly when idling. It gets a little better when put into neutral, but not much.
I've had two people suggest possibilities:
- Fuel filter
- Vacuum hose
This started happening in the last year or so. It started out being a mild shake when stopping at a stop light, but in the past 6 months or so it's any time the car is not moving.
The car hasn't needed much maintenance recently, but in the last year I've done:
Oil changes ever 3-4,000 miles
Replaced all spark plugs
Replaced the radiator
Replaced the front brakes (I know this probably has nothing to with anything, but it is something that's been done)
I think that's it. Also - it seems to get marginally better when I add a quart of oil to it (it leaks a little oil, that's another issue for another day).
I have not done much troubleshooting on this or taken it to a mechanic. I wanted to get some insight on things I could start with or try. I don't mind spending a little bit of money on easy fixes that may or may not resolve the issue, but that wouldn't be bad for the car either.
This is the RPM at which it idles:
Any other suggestions?