QuestionWhen I have the car in drive, either accelerating or cruising, the car will stumble and I notice the rpms go up and then down again. I've got platnum plugs installed less than a year ago and new wires. Also my tran oil is reddish brown - probably changed about 80,000 km ago (car has 194,000km.).
Can you tell me if this is a tranny problem or electrical from the information I've sent?
AnswerSam,
Your tranny fluid should be a reddish brown color. That's just the way automatic transmission fluid looks. Though it is good to replace your tranny fluid and tranny filter between 36,000 miles to 45,000 miles (58,000km to 72,000km). So, you're probably due to have it replaced.
The stumbling (sometimes referred to as 'bucking') is usually caused by incorrect air flow or insufficient fuel being supplied to your engine. Have your air filter, fuel filter and PCV valve replaced if you haven't done so within two years. Also, it may be necessary to have your intake plenum and throttle body pulled and cleaned. Your EGR valve should also be cleaned. Have your fuel pump inspected as well to make sure it's operating at it's full capacity.
Good luck!
