help, please!!! 96 sierra

[chevywoman15]

Hello everybody, I recently bought a 96 gmc sierra 1500 z71, 5.7l vortec and automatic transmission. It is doing this very odd thing where it will rev itself up, so you take your foot off the gas and go to put your foot back into it and it will rev up but wont actually accelerate until 3-4rpms. It engages into all the gears normally, check engine light is on so I had it scanned and all that came up was a cylinder 5 misfire. Tranny fluid was a little low, so I added some and it is still doing it. Please help me figure this out!

[Doug_Scott]

Hello everybody, I recently bought a 96 gmc sierra 1500 z71, 5.7l vortec and automatic transmission. It is doing this very odd thing where it will rev itself up, so you take your foot off the gas and go to put your foot back into it and it will rev up but wont actually accelerate until 3-4rpms. It engages into all the gears normally, check engine light is on so I had it scanned and all that came up was a cylinder 5 misfire. Tranny fluid was a little low, so I added some and it is still doing it. Please help me figure this out!

 

I am going to make an assumption here. When you say "it engages all the gears" do you mean that it engages all the gears when you use the shifter? For example, going from \Park to Reverse, it goes into reverse. Then from Reverse to Neutral, it goes into neutral, and then from Neutral to Drive it goes into drive. Same for any of gear positions below Drive(don't know what your shift quadrant says). If that is what you mean, then it is not actually a test for all gears.

 

When driving off from a stop, it starts in 1st gear and should shift into 2nd gear on its own at about 15mph(depending on rear axle gears), then shift from 2nd to 3rd at about 25mph, then into OD at about 30 to 35mph. The speeds are likely different, but, the point is you should see the rpm rise as you pull away, then drop in rpm as it shifts to the next gear, and repeat until into high gear with lockup convertor.

 

Your description really sounds like you don't have second gear. I say that due to your description about the rpm increasing, and after letting off, it will just rev back up to where it was before you let off. When the transmission is in Drive, and starting from a dead stop, it will start in low or 1st gear. There is no engine braking when in drive. There is a over-running clutch that only engages when driven in one direction. Letting off the gas, will cause that over-running clutch to free wheel, so engine rpms drop to idle when you take foot off gas. When you step on the gas, the engine has to catch up with the transmission. If you put the transmission into manual low gear, that applies a band in the transmission that holds the over-running clutch from spinning when you let off gas. You will feel engine braking, and stepping on the gas will not cause the engine to rev rapidly like it does in Drive.

 

From all that above, it means \I think you have lost 2nd gear.

[gmtech4]

what does "3-4rpms "mean ?

 

what does "rev itself up" mean ?

 

soumds like the tranny maybe donedonedonedone,,,

 

 

doug ,,,just say the tranny is finished already lol jeeez lol

[chevywoman15]

I think you know what those terms mean ****

[8.1HD/ALLISON]

I think you know what those terms mean *****

We don't need name calling. People are trying to understand and help. Please read the forum rules.

 

Sent from my LGL86C using Tapatalk

[gmtech4]

i do but its confusing and need to understand where your coming from ,its all good though ,,,,the 3-4 rpms was i figured 3000-4000 rpms but was just making sure

 

tranny is finished anyways

 

good luck

[DaveH71]

Sounds like a slipping trans to me.

 

When you checked the fluid was the truck up to temp? Take it on a good 20 minute drive and then check the trans fluid again with it in park. Should be in the warm range.

 

What does the fluid look like? Is is brownish, or clear pink or red? Does it smell burnt?