[Logo] GDE Forum - Home for the best in diesel powertrain tuning
  [Search] Search   [Recent Topics] Recent Topics   [Hottest Topics] Hottest Topics   [Top Downloads] Top Downloads   [Members] Member Listing   [Groups] Back to home page 
[Register] Register /  [Login] Login 
Messages posted by: schwifi
Forum Index » Profile for schwifi » Messages posted by schwifi
Well, I guess I didn't check the drive line as closely as I should have. Got the Jeep into a dealer and they discovered the u-joints on the rear drive line needed changing. This made a lot of sense in that the vibration came on slow and started getting worse. I have had u-joints go out on me in the past in other automobiles and it was real obvious what the issue was. The Jeep just showed up as a vibration between 45 and 60 MPH under light load - no clanging when accelerator pedal was oscillated as was the symptom on previous automobiles.

Anyway, the vibration went away after the u-joints were replaced. Hope this does it. We bought the jeep with 75K miles on it and really don't know what kind of use and abuse it had before then. Seems like 90K for u-joints is a little soon. We have also replaced front wheel bearings which seem a little soon for those also.

Mavalos - might want to check u-joints (you probably already have). They are the easiest and cheapest to change (I think). I haven't worked on the differential or rear wheel bearings in this jeep - hope I wont have to for a long time! Hope you find a solution to your problem, and thanks for posting!
The GDE reflash didn't help the vibration. Will check the EGR tube and rear axle.

Thanks for the response - the vibration is present in the 45 - 55 mpg range with the OD off (approx. 2000 rpm) - approx. 1800 rpm when OD on. It happens only under light load - cruising. Under acceleration, the vibration isn't there - or much less noticeable. Also, if I put the transmission in neutral in this range, the vibration goes away. I'll admit, the vibration does feel like an out-of-balance drive line - or what I would expect an out of balance drive line would feel like (I've never had one go out of balance before). But an out-of-balance drive line would vibrate when the transmission is shifted to neutral.

A little more about the maintenance of the vehicle. The front wheel bearings were changed about a year ago. The Turbo charger was also replaced about a year ago also - old one failed just after the GDE tune - I didn't see it but I guess the adjustable fins in the compressor flew apart. It had been making some noise before the GDE tune so it wasn't a surprise. When I installed the GDE tune, I blocked off the EGR tube going from the intake to the cooler. Also, the transmission has always had a intermittent hard shift from 2nd to 3rd when cold. Doesn't happen all the time, but it is noticeable when it happens.

Since this vibration didn't start until after my wife took it to the dealer to see if they could replicate the ICU hiccup, I was curious if they didn't reflash the ICU with the stock program. That would have turned the EGR back on, but I have it blocked, so was wondering if that isn't causing the vibration. It only happens in that range where the EGR would be active. The vibrations are less noticeable when cruising above 60mph. The ICU is not throwing any codes.

The last thing I though - maybe the EGR tube I blocked block is leaking high pressure air. This would cause the engine to be less responsive but not sure it would cause the vibration. I haven't checked this yet.

Any Ideas you have are welcome - will check the rear breaks also, as per you suggestion.
I have a 2006 Jeep Liberty crd with a GDE eco tune (full torque). It has 105,000 miles on it and replaced the timing belt at ~90K. The GDE tune was added when the timing belt was replaced, and has been running well for over a year. A vibration has developed in the last 6 weeks during vehicle operation between 45 to 55 mph when under cruising speed load. The vibration goes away (or is significantly less noticeable) under full throttle acceleration, and is not present under no-load (45-55 mpg and transmission in Neutral). Only seems to occur when cruising between 45-55 mph. No vibration when cruising at 70mph

The problem started when my wife started the vehicle and according to her, it ran rough, no power, had a hard time keeping the engine running. After driving for a mile or two, the vehicle died in a parking lot. She shut the vehicle off, then started it again and it ran fine. She took the vehicle to the Dodge/Jeep Dealer to see if they could recreate the issue, but were not able to. The only thing they told her was that the computer indicated a "misfire". I have since connected my OBD II code reader to the vehicle, and get no codes at all - no engine codes or transmission codes. Not sure what a misfire code means for a diesel. Anyway, the vibration started after she picked it up from the Dodge/Jeep dealer.

I have run the engine mount check per this forum on engine mounts, but there is no vibration when I shift from park/neutral to drive or reverse.

The barometric pressure sensor, MAF sensor, and turbo boost pressure (map) sensors were replaced when I replaced the timing chain.

I am thinking about re-flashing the GDE tune into the computer - Not sure if the Dealership may have messed up the Tune in any way.

Anyone have an Idea what this might be?
Forum Index » Profile for schwifi » Messages posted by schwifi
Go to:   
Powered by JForum 2.4.1 © 2015 JForum Team • Maintained by Andowson.com