[JSH]

Originally Posted by ZLRob

You know speaking of the thermostat I really gotta wonder where they are located on 17's like my own. I wonder if they are still in the valve body or if they are in the cooler line or somewhere else entirely. GM went and changed so many things from year to year and have no indication of it apparently, which makes for really annoying and frustrating inspection, service, and repair procedures on these cars.

Also to anyone else reading this, you need to make sure you are at your cars exact operating temp (when your thermostat is set to open) before you pull the plug. For my own 17 it was set to 203 degrees F*. My temp to pull the plug was exactly within this specific range.

For others you may be able to pull it around the 170-180 mark as some of the later Z's ran a cooler thermostat.

It is worth noting that the overfill on mine was making the transmission run a full 4* hotter, because the moment I pulled the standpipe level plug my temp went from 203* to 199* immediately after. I checked these temps immediately after reinstalling the level plug and was surprised by just how much a difference this what otherwise would be considered trivial difference in level made.

Has your TCM been tuned? By way of example, mine has adjusted base pressure, Line pressure, Offset pressure, all adjusted for the setup, as well as TCC setup and shift times adjusted.

Does it slip mild throttle, wot only, partial, which gear? Was the level inspected?