is it engine or transmission problem?

1999 T&C with 104k

The van started acting slow from 90k. The sympton is as follows: van sometimes pick up speed pretty fast at traffic light but it may hesitate and vibrate at the next traffic light.

I am so confused what's causing this. It coasts smoothly same as most of members's experiences.

This hesitaation may happen at the first gear to 2nd or 2nd to third (more often).

Is my engine not clean or the tranny?

Have You Had The Transmission Flushed And Had The Filter Changed?

when did you last change the leads and spark plugs?

9k miles ago/6 months ago

Have You Had The Transmission Flushed And Had The Filter Changed?

Will do trans flush in one to two weeks, trans filter was changed 60k (now it is 104k), oil filter just changed 700 miles past

check under your hood while the engine is running and listen for a whistling noise, either loud or soft. You could also, possibly, have a vacuum leak in your intake manifold.

Did you ever consider the possibility that the cat may be going bad. Failure to exhaust gasses from the engine can cause loss of power and the sluggish symptoms you describe.

is it something that computer diagnosis will show?
dealer could not locate any error code at this moment.

Also check your air intake duct from your air filter. If it's opened up anywhere, you can suck air in, bypassing your sensors. This in turn could cause your computers to adjust things wrongly. Long shot but a cheap check.

Computer analysis in its true sense will not detect a bad cat unless the plugs are fouled to the point where you are getting misfires. One symptom is a loss of power and it will gradually get worse. With the mileage you indicate this is a possibility. Also what B33p3r indicated is also true so you may want to try his suggestion first.

Computer analysis in its true sense will not detect a bad cat unless the plugs are fouled to the point where you are getting misfires. One symptom is a loss of power and it will gradually get worse. With the mileage you indicate this is a possibility. Also what B33p3r indicated is also true so you may want to try his suggestion first.


a 97 caravan I worked on did throw a code for the cat somthing like a high backpressure code but it told us to that the cat was bad so u might want to get the codes read somewhere

Transmission flushed and engine cleaned with Auto-RX. The condition is 80% improved.