I have a 97 z28 with about 68k on it. My heat stopped working towards the end of last winter and now that is begining to get cold in the morning here in new jersey its on the top of my list right now of things to fix. i was wondering if any1 has and suggestion on where to start or what it could be, i dont believe its the heater core however because the anti-freeze smell does not exsist in the car. My ac works fine my mode switich and fan switch also seem to work with no problems. Dont know if it could be my temp. switch , when you turn it, it sounds as if the flap is closing and opening, any imput would be great, and also if any1 has any suggestions on where to start, i dont want to go to a shop because its just gonna get to expensive with the hourly rate just over 90 dollars here thanks you any suggestion would be greatly appricaited

 

99% chance that the heater core is clogged. Remove the hoses at the water pump and flush with a garden hose into one and then the other. Keep the opti dry.

 

I have a 160* thermostat and my heater only gets "lukewarm". Core is new and so are the heater hoses. Is that normal for this thermostat?

 

I'm in NJ, have a 160* t'stat, and the only difference I noted between the 160* and the stocker is that is takes maybe 2 minutes extra on a very cold day (sub-freezing) for the heat to reach comfortable levels. I have not found the 160* 'stat to cause a lack of heat.

Are you sure you have the correct "LT1" reverse-flow t'stat? Are you sure its working? What temperature does the dash coolant gauge indicate when the engine is fully warmed up? Since you have the lower temp t'stat, were the fan on/off temperatures reprogrammed lower? If so.... how much lower?

 

Ok I might have a problem then. The pcm is tuned for the thermostat and the fans are working. Maybe its clogged.

 

That flow restrictor may be clogged. Mine was; it's now removed and replaced with a coupling.