Jumping and Grinding at Low Speed

[Jgranville]

Hey All,

I'm having a lot of slipping in the transmission. I hit the gas and the engine revs and the ride is slow and rough, then all of a sudden something feels like it's grinding, and then it jumps and jolts a few times and we're off. It doesn't feel good in the gas pedal either. It gets soft and shakes a lot.

Any ideas on what this is?

 

[tonydiv]

Could be a lot of things. Anything from bad coils to a bad transmission. We really need a better description of the problem (codes?) and the truck to give you any more insight.

 

[bedrck46]

also would be nice if you list year model engine and which transmission you have. The more information you post about your problem will help in getting better answers. Takes most of the guess work out of the problem

 

[Jgranville]

It's 2000 XLT with a 4.6 and 160,000 miles. I hooked it up to our MODIS scanner at work and the only code showing is a P1875. All it means is the car reached redline. It has very slow acceleration as it is. You press the gas, nothing nothing nothing, and then all of a sudden the tach flies to redline and you start picking up speed. That's usually only in hills or infamous though. This issue now is leaving stops, like I said. The medal goes soft and shakes, and it feels like it doesn't want to go forward. I cannot tell where the grinding is coming from, but it is a very rough, rumbling, acceleration. Leaving a stop sign, the tach will be at about 25-2700 rpm sand I will only be doing 10mph. Then the car jumps, and it settles down and I can be on my way.

 

[JUST4FUN]

sounds like first gear is saying bye, my first gear is starting to go south too

 

[Jgranville]

I'm getting it on the freeway too though. The city stop issues are annoying. The highway problems are scary. I step on it, nothing happens, then it redlines and makes this awful sound. I don't even know to describe it. It's a grind/whine

 

[FordandPolaris]

When were the plugs and coils last changed? If it is happening in all gears, it is either engine related or torque converter related, and that doesn't really sound like TC to me. I have had it where I was getting bad misfires and had to kick her down to get the truck moving. New plugs and coils smoothed that issue out considerably.

If your plugs are original, they are well past due and are very possibly the culprit. Especially if you get shaky rumbly acceleration.