2001 Trooper flutter problem

I've read through other posts but did not find anything to match my problem exactly. My 2001 Trooper flutters for just a few seconds between 35-50 mph. The throttle position sensor has been replaced as well as the control box. Every time I have it at the dealer, of course it doesn't flutter EVER. It is intermittent, although at least once or twice per day. This has been ongoing for over a year. The Trooper has been a dream to own, but this is very frustrating.

.... My 2001 Trooper flutters for just a few seconds between 35-50 mph.....
any other info? gear dependent? rpm dependent? air temp, eng temp, steady gas or on accel or decel??? etc

//bc

Low are dirty tranny fluid?

I don't know what flutter means?

Flutter is like it is not fully engaging or jerking motion. Very rough vibration. Tranny fluild ok. If kept in 3rd gear to 50 mph, no flutter. Happens on steady accel, never on decel. Also never on hard accel. Air and engine temp ok. Seems to be not fully engaging in drive. Please define gear and rpm dependent. Ck engine light no on so dealership can't get a code, or so they say. Thanks for your replies.

any other info? gear dependent? rpm dependent? air temp, eng temp, steady gas or on accel or decel??? etc

//bc

history on the tranny fluid? How many miles on the the truck?

.... Please define gear and rpm dependent. Ck engine light no on so dealership can't get a code, ...

what i mean is: does the condition depend on what gear you are in. have you tried different gears to see if there is a difference?

and...does the condition depend on what rpm range you are in, i.e. does it happen at a particular rpm, no matter what gear you are in?

and now my wild arse guess: at this point that's all it could be. but i'm thinking it might be egr valve related...the only thing that doesn't compute for that is the "Very rough vibration" part. but that just might be different ways of describing the same thing.

if the egr is sticking open or isn't fully opening when it shouldn't, then it's problem can show up in the situations you are describing. my 1992 trooper has a different egr valve set up, i believe, so direct correlation might be difficult.

but...i had a rough running situation that i could duplicate in 3rd at steady throttle at approx the same rpm. when i cleaned out the exhaust gas backpressure tube of the egr valve, the symptom went away. the rest of my egr valve was fine, but it wasn't operating properly because it wasn't getting the proper input from the exhaust gas backpressure circuit. [i could see the egr pintle opening and closing when i visually tested it, but it wasn't doing it's thing as fully as it should have nor when it should have, which i really couldn't tell from that kind of testing. also no code set]


hth

//bc