I'll try to include all the symptoms in this post. Vehicle is a 2000 Tahoe LT 4WD 5.3L engine. It has 80K miles and is not used for towing.
Transmission was replaced in June 2011 at 76K miles after a "Complete Metal Failure". The Tahoe has only towed a small trailer with pine straw on it, and 4WD has only been used a couple of times on dirt roads. After the xmsn was replaced everything was fine until about 2 months ago. The replacement transmission is still under warranty by Chevy. Here are the things it is doing.
1. At times, after stopping at a traffic light, I give it light throttle, the engine revs but the truck doesn't move for a few seconds, then it engages like someone hit you from the rear. Dealer says "no trouble found".
2. When driving on a level road I can give it a little more throttle and the engine revs up 200-300 rpms, then drops right back down again. At that point it sounds like the truck is laboring (growling). This can be duplicated over and over. Almost like it's slipping then catching.
3. When going up a slight grade with steady throttle, the rpms will go up and down by about 300 or so rpm, like it is surging. It also "growls" (sounds like a hard vibration) when the rpms lower each time. It takes heavy pressure to get a downshift. It never had a problem with slight grades before.
4. When driving in 3rd and going down a hill with no throttle, after 20 or so seconds it's almost like the transmission has down shifted.
5. When shifting from 2 to 3 in drive, there is a long hesitation almost like the transmission is slipping then locks up.
I've replaced the TPS, fuel filter, cleaned the MAF and had the throttle body and rails/injectors cleaned at the dealer. It idles fine except even at 500 rpm it feels like it wants to take off from a stop. If I let off the break it starts to move forward quickly.
I'm not sure where to begin. I have an ElmScan 5 that I can hook up and record the sensors readings, but I don't know what I am looking for. I'm starting to suspect the TCC or the input to it. When I give it hard throttle, it seems to be fine. It's not throwing any codes and on the highway in OD, it seems okay, just sluggish. My MPG has gone down slightly, but I still get about 17-18 MPG on the highway.
Anyone have any thoughts???
Thanks,
Mark
Transmission was replaced in June 2011 at 76K miles after a "Complete Metal Failure". The Tahoe has only towed a small trailer with pine straw on it, and 4WD has only been used a couple of times on dirt roads. After the xmsn was replaced everything was fine until about 2 months ago. The replacement transmission is still under warranty by Chevy. Here are the things it is doing.
1. At times, after stopping at a traffic light, I give it light throttle, the engine revs but the truck doesn't move for a few seconds, then it engages like someone hit you from the rear. Dealer says "no trouble found".
2. When driving on a level road I can give it a little more throttle and the engine revs up 200-300 rpms, then drops right back down again. At that point it sounds like the truck is laboring (growling). This can be duplicated over and over. Almost like it's slipping then catching.
3. When going up a slight grade with steady throttle, the rpms will go up and down by about 300 or so rpm, like it is surging. It also "growls" (sounds like a hard vibration) when the rpms lower each time. It takes heavy pressure to get a downshift. It never had a problem with slight grades before.
4. When driving in 3rd and going down a hill with no throttle, after 20 or so seconds it's almost like the transmission has down shifted.
5. When shifting from 2 to 3 in drive, there is a long hesitation almost like the transmission is slipping then locks up.
I've replaced the TPS, fuel filter, cleaned the MAF and had the throttle body and rails/injectors cleaned at the dealer. It idles fine except even at 500 rpm it feels like it wants to take off from a stop. If I let off the break it starts to move forward quickly.
I'm not sure where to begin. I have an ElmScan 5 that I can hook up and record the sensors readings, but I don't know what I am looking for. I'm starting to suspect the TCC or the input to it. When I give it hard throttle, it seems to be fine. It's not throwing any codes and on the highway in OD, it seems okay, just sluggish. My MPG has gone down slightly, but I still get about 17-18 MPG on the highway.
Anyone have any thoughts???
Thanks,
Mark
