Still shudders...now funny noises

OK...I'm starting to get upset. My 2002 Trooper (45K miles), which has been bulletproof so far, is now acting up. The worst part, is that nobody believes me (at least my dealer).

I need your help. My vehicle, which I love, is not running the way it should.

Let me try to explain my situation...

1. About one month ago I took my Trooper in to have the Tranny Flushed and grease the drive shaft (enter jokes here) zerk fitting.

2. Later that evening I power washed my engine. I first sprayed Simple Green on the engine, let it soak for a few minutes and then sprayed clean. I am very careful not to spray up close with high pressure water. I stood back five to six feet and let the water work.

3. Over the next few days, I noticed the car would shudder when I was in overdrive at low RPM's. For example, as I would climb a slight incline, the car would shift through the gears as it normally would. But as soon as it hit the final shift, it would begin to vibrate. It doesn't do it all the time, however, when it does it's typically in OD and low RPMs (around 35-50 MPH).

4. Took it dealer. They drove it and it performed flawlessly. They checked the codes and verifyed the tranny was full. Returned the vehicle to me with no fix. Only positive thing is they documented the "issue".

5. Driving around town...still acts up. I'm now watching/listening for any sort of sign that I can pass on to the dealer. I now notice that the Trooper is making new noises. Again, high gear (Overdrive) and low RPMs, the Transmission surges and groans (for a lack of better words). It sounds like the torque converter is kicking on and off. I also notice at various times, a sound coming from the engine compartment. It sounds like a muted locomotive horn. Not sure what the heck that is.

6. Take it back to the dealer. Again they drive it and nothing. Frustrated, I asked the Service Manager to take a ride with me. It doesn't do it. I drop him off...on the way home it acts up and start to shudder/vibrate. Just my luck.

7. This past weekend I run 1/2 can of Seafoam through the motor (about 20 miles worth of driving). I change the oil/filter and add Full Syn Mobil 1. I change the air filter and top off other fluids. Start it up and it does seem to idle a little smoother. Take it out for a test drive. Runs good and strong. Decide to head home...car starts to shudder again. It also makes that annoying sound from the tranny/torque convert and the muted locomotive horn. "It's" still there.

So...that brings us to today. It's still acting up. I'm not sure which way to turn.

I need your help and advice...What do you guys think is going on?

Your feedback is greatly appriciated!!!

If you are not getting any CEL, check trans light and your dash PRND321 lights dont go crazy (bad TRS) This could be a bad intake manifold gasket. IIRC, Amigo-2K had a similar issue with his 2000 3.2L. The torque converter would lock/unlock randomly in OD. A new IMG fixed it.

G/luck
Joel

Had a similar shudder problem with my trooper. Turned out to be the wrong gear oil was used in the rear differential by the shop. Had it replaced and it took care of the problem. I would confirm the transmission fluid used and check the differential in case it had been replaced in the last six months or so.

This is my first post here-- I have a 2001 Trooper sitting in my driveway that I'm trying out. It is making the same strange noise in OD like a growling sound. It also shudders sometimes. I can buy it for $4500 or less because of this problem. It is loaded with all power options, leather and sunroof. The tires are good. It has some scratches and scrapes and the int. is dirty but overall in good condition. This seems like a great deal to me if this isn't a major problem. What do you guys think? Thanks, Jim