Revving too high before it will shift...

[9CZ71Denali]

Hello all,

I have an '03 Z that has been well maintained. Recently the engine is revving higher than normal before it shifts, sometimes I have to let off the pedal to get it to shift. Is the tranny going bad or maybe an engine problem? Also quite a bit of pinging and knocking lately. No CE codes when I scanned it. Ran seafoam through it and cleaned the TB about a month ago.

Recently switched wheels from 18"s to 16"s, I havent re-programed the bcm, so my speedo is off too. Could this issue be with the TCU?

Thanks

 

[DarkTahoe00]

I'd lean more towards the tranny.but I've heard some people been able to put the vette servo in and it help to stop it. With the seafoam it may have loosen some of the stuff up and that might be why your getting the pinging/knock. I'm sure some of the other guys will chime in and correct me if I'm wrong or with some other insight!

 

[Justin]

Have you adjusted your intake tube or modified your MAF in any way? Unmetered air would be my first thought with respect to an abruptly new pinging problem.

When the transmission does get around to shifting, how is the shift quality? Does it feel like it's sliding out of gear and then snaps into the next gear or is the shift quality pretty decent?

 

[Grebbler]

Are you running with the TOW button on?

 

[Rollin Thunder]

Are you running with the TOW button on?

Its sounds like it, But the tow button must be hit every time you start the vehicle.

 

[9CZ71Denali]

The truck has 81K miles on it, trans fluid/filter changed over the winter. Maybe that is what is killing (killed) it?
When it does finally shift, it is smooth.

I am having a multitude of other issues all of a sudden...

When I accelerate hard (in 4th or 5th), it revs high but doesn't accelerate (as if I were in neutral). When it does respond, there is a rattle from the drivers side or center of the engine compartment.

The engine is louder than normal when accelerating.

Idling rough, the whole vehicle vibrates and shakes.

Tow mode is off, but it drives as if it were on.

My baby is dying! Help!

Thanks in advance...

 

[shsportsfan12]

start building a new motor/tranny

 

[munks06denali]

check tranny fluid level, quality of fluid(brown/smells burnt) As far as rough idle , check your fuel pressure regulator. If I remember correctly its on the drivers side valve cover sticking out of the fuel rail with a little vacuum line running to it. Pull that line off and start the truck, if there is fuel present the nthe bellows in the regulator are bad. I have seen this a few times i friends trucks as well as my old 2K Z71. Hope this helps.

 

[nc6600]

The truck has 81K miles on it, trans fluid/filter changed over the winter. Maybe that is what is killing (killed) it?
When it does finally shift, it is smooth.

I am having a multitude of other issues all of a sudden...

When I accelerate hard (in 4th or 5th), it revs high but doesn't accelerate (as if I were in neutral). When it does respond, there is a rattle from the drivers side or center of the engine compartment.

The engine is louder than normal when accelerating.

Idling rough, the whole vehicle vibrates and shakes.

Tow mode is off, but it drives as if it were on.

My baby is dying! Help!

Thanks in advance...

My old Tahoe did that turned out to be Intake gaskets, as for the rest i really dont know sounds like your transmission is taking a

 

[9CZ71Denali]

check tranny fluid level, quality of fluid(brown/smells burnt)

Clean/smells fine...

The thing that is getting me the most is when I accelerate, I don't go anywhere...