Dear Scotty, I have a 1997 Chev Silverado 1500 extended cab 2WD, 5.7L Vortec, with what I am told is the most common automatic transmission that came in it new. It has 206,000 miles and it was my daily driver for 12 years. My problem is that the transmission started not shifting to get over 20 MPH or so. I checked transmission fluid and it was full. Then I noticed that it would overheat very quickly, within 3/4 of a miles or so. And when I say overheat I mean the radiator was boiling over. I took it to an independent shop that I have used in the past and have always been satisfied with their work. They said that it sounds like I have a crack in a wall between 2 cylinders and that it is causing the transmission not to shift. They said will probably need another engine and possibly another transmission. Another shop said that it may be a blown head gasket due to oil being expelled on the driver's side of the motor. He also offered to buy the truck for $1200.00. What do you think?
Thank you very much,
Tony Roberts
Did either of these shops actually perform any diagnostics or were they just guessing? (I don't see how an alleged crack in the block would affect the transmission shifting unless some kind of limp-home mode was being triggered by overheating.)
Anything is possible at that age and mileage but for such serious potential issues you would not want to rely on guesswork.
@chucktobias No diagnostics were performed. The one shop said that in that model it is common for the crack in the block to cause a back push into the radiator and that will cause the transmission to not shift. That is all I have been told.
If it were common I'd think it would show with a quick internet search. That's not the case, doesn't seem to be very common. It would be easy enough to test for combustion gases in the radiator, you could do that at home with a kit. The only way I could imagine it affecting the transmission would be triggering a limp-home mode when overheating.
https://www.carcomplaints.com/Chevrolet/Silverado/1997/