Engine "floors it" at 30mph

[Ryan G]

Yesterday, on my way home from work, I stopped at a red light. When it turned green, I slowly pressed on the gas pedal as normal, not flooring it or anything. When it reached about 30mph (or maybe it was about to change gears), the engine automatically "rev'd", made the sound like I slammed on the gas pedal, and the RPM's went up for maybe 1 second and the truck gave that little "pause/ jump" like it would if you had slammed on the gas pedal. When I go from 50mph down to 20mph, it doesn't do that. Only when I make a complete stop, then accelerate. It happened a couple times and I'm trying to find out if it's at certant speeds, when certant gears change, if engine is hot/cool, etc. but this just started yesterday.



Does anybody know what this is??? Please help and thank you in advance for your replies!

 

[Todd Z]

Sounds like the start of a tranny shifting flair.........



Todd Z

 

[Doug Watts]

Get the fluid changed yesterday! The clean fluid should help, but you're going to need to rebuild the valve body if that doesn't work or you'll be rebuilding the tranny.

 

[Larry Phillips]

At a minimum before rebuilding the valve body, check the valve body gasket first.

 

[EddieS'04]

Yup,,tranny flair. Most likly fresh fluid and valve body work. Try disconectin the neg battery cable for 15 minutes. Then drive it like you stole it. If the flair goes away. Drive it with some extra throttle on take off for awhile. The computer might relearn shift pattern. It will be temporary though.

 

[Scott Tanner]

I wonder if your cruise control is not cancelling out when you hit the brake.... hmm

 

[Ryan G]

STanner - I havnt used cruise control for months so I havnt pressed those buttons ever since.



also, when you all say "tranny shifting flair", what exactly does that mean? Is the tranny ready to crap out on me or just slipping?



Also, where is the valve body located? Thanks again for your help!

 

[Jim parnell]

do a search for 2-3 tranny flair or a variations of that, you'll see numerous posts. The flair is when the tranny "hangs up" between 2nd and 3rd gear, it will seem like it doesn't want to shift into 3rd, and then finally will shift. The shift solenoids are worn, weak springs (not an expert on this) and will cause shifting issues. Have you had the "wrench" light up on the dash, that is the indicator that something is really wrong with the tranny, and you should have it looked at by someone you trust if all possible. A fluid change may "fix it" but then it may just delay the eventual situation of a tranny rebuild or replacement. Rebuilds are cheaper while a new/remanufactured tranny is about $3K installed. The valve body is located in the tranny, there is a projecdt or 2 on it, again, search for valve body and you'll see more info than you really want to see. GL

 

[Don Donaldson]

Having a Gen 1 V6 there will be no wrench light... Instead if the transmission is breaking the O/D off light will flash.

If its a shift solenoid/ valve body it is not too expensive relative to a new transmission.

The valve body is the square object at the bottom of the transmission that the transmission filter plugs into. It also has the shift solenoids (round black objects) sticking out of the sides. If you where to take the bottom cover off of it you would see a labyrinth of passages for fluid to pass through. It would be my suggestion that you take it to a GOOD transmission shop and explain the problem and the possible causes that where named here to aid in diagnosis. Also I have an good spare 5r55e transmission but it dose have a lot of miles (160k).



Good luck and keep on trac'n

-Don D.