I have a 2000 xlt 4x4, recently had to have the engine replaced cause the mechanic that had worked on it last told me that the oil gauge was acting funny cause the oil sensor was bad, but was ok to drive. Turned out it wasn't the sensor, but the oil pump, and I destroyed the engine. They replaced it for me, but now when I'm driving it starts to buck when I get to 50mph, then again @ 60mph. Anyone know what's going on, and if it's something I could fix easily myself.

 

it's trying to throw you off. you probably just need new seat covers

 

ha ha

 

I agree.

 

thats funny... check your gas and clean all the cleanable stuff... tb, maf, iac, air filter and check fuel pressure... mine did that for awhile after a fill up and it went away after the next one so it was bad gas for me

 

does this happen when its wet outside?

I had the same problem. After countless trips to the dealer while under warranty, a rebuilt transmission at 14K, they figured it out, it was a solenoid on the (brain fart) looks like a donut filled with fluid on the transmission, has 'paddles' that turn inside it and thats what makes your truck move... total brain fart moment LOL

 

Torque convertor?

 

Yes! that! LOL theres a solenoid, well theres a couple of them, that at certain speeds, detect when it should 'lock up' If this solenoid isnt working correctly, youll get the sensation that the truck is bucking. One of the sure signs of this problem, is to drive the truck in the rain, or while its snowing. Hosing down the under carriage, wont work. Atleast it didnt for me.

 

FMD, very interesting. Mine has been doing the same thing. I'm not sure what the issue is, but that may be my problem too! Sometimes it just feels like I'm going over bumps and my foot is bouncing off the accelerator, but it's definitely bucking. Mine only seems to do it when I barely have the accelerator press, instead of at WOT or no throttle at all. Did yours do the same? (and yes mine does it more noticable when snowing or raining)

 

I should point out that taking the truck into the dealer to have the codes pulled is a waste of money. I had a recorder in my truck, a little black box with a red button... push the button when the truck acts up, and it takes a snapshot of everything in the trucks computer.

This particular problem does NOT show up! No codes, and no 'problems' recorded by the computer. It wasn't until the service manager took my truck home one night, and while driving into work in a snow storm drinking his coffee, the truck ruined his nice white shirt.

Generally at cruising speeds, like 30-45 mph its most notable... feels as though the truck is literally 'stopping instantly' for a second... Its a very disheartnening feeling.

 

MAF sensor, a bad seal on the air filter or a loose air box lid can cause this too without codes

FMD, had they watched the TC_SLIPACT and TC_SLIPDSD outputs on the PCM they would have caught that immediately