2002 Yukon starts bucking around 50 MPH

rgmurphy1rgmurphy1 Member Posts: 1
edited March 2014 in GMC
My yukon startes bucking around 50 mph. The transmission shifts through all the gears perfectly. The rpms do not change when this happens. Its not a constatant buck, when you increase speed it will eventually stop. Before I take it to a transmission machanic, any suggestions on problem?


  • brianlittkebrianlittke Member Posts: 4
    I had a similar sounding problem in an '05 XL with 12K miles. Ended up, there was water intrusion into the transmission. It was caused by water running into the transmission dipstick. GMC ended up putting a diverter in to run the water away from that area. haven't had a problem since.
  • rshtrsht Member Posts: 277
    My guess of your engine bucking problem is fuel injection related (i.e. Fuel pump, Fuel Injector...). Did the Check Engine light ever come ON during that period? Even if it did, I would assume the Check Engine light did not stay ON long enough for you to extract the Trouble Code as the problem only shows at ~50mph...
  • toosmoothtoosmooth Member Posts: 1
    yes i have had the same problem with my 2002 denali and recently(last week) added bmg oil addititve for higher mileage engines to oil change and problem has gone away for now .dont know if this is the cure all but so far so good .let me know what you find out!!
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