I would recomend you replace the ignition wires and spark plugs unless you know for sure that they are not very old and have not broken down. If you spilled any anti-freeze and it got into the spark plug wells because the seals on the wires leaked that would cause an intermittant miss. If you want to check vacuum just temporaraly plug off all of the vacuum hoses at the engine. A vacuum leak would tend to be more regular and have it's greatest effect on the idle. If you have ANY doubts about the automatic trans slipping test the line pressure. A disconnected vacuum line to the modulater would affect shifting. Make sure it is not leaking, plugged, or disconnected. It is difficult to work on the front of the motor but that is where most of the vacuum hoses are. If the idler pulley bearings are noisy they should be replaced, they aren't expensive and it isn't difficult. David Teitelbaum vin 10757 --- In dmcnews@xxxx, "Ed Garbade" <edgarbade@xxxx> wrote: > Noticed my car performs OK in low gear but bucks as I move up in RPM and > gears (this started a couple weeks ago when I changed the antifreeze). I