2007 chevy silverado transmission shift problems

[planet]

I recently bought truck and this problem started, when you are pulling out in first and moving along and it won't shift into 2nd until you back off on the throttle. Then it shifts up into 2nd and 3rd and 4th and lockup as expected. The fluid is clean and no burn smell. Had autozone read the comp. and it showed no errors. I am thinking about using lubgard aditive for transmissions to free up valves.

[desrtrat]

clean your MAF first, then go from there..dirty MAF is known to cause trans shift issues. even if it looks clean, do it anyway with CRC MAF spray cleaner..

[TJMaine]

Mine does this too sometimes, be a good maintenance item.

[planet]

I cleaned my intake today and there was alot of black soot like material on rag. Any ideas as to where it could have come from.

 

Thanks in advance

[Doug_Scott]

Almost always the result of camshaft overlap and to a lesser extent oil vapours in the crankcase vent that gets pulled into intake manifold by PCV system, and is 100% normal. This was why you were cleaning the intake wasn't it?

[planet]

Thanks for the info