I just purchased a 2001 ZR2 2 days ago,209,000 miles it runs great!

Everything on this ZR2 is working properly.

+But when I checked the tranny fluids it was 3 quarts low,[it does not leak any fluids]

***How can it be 3 quarts low , if it's not leaking transmission fluids?

Why would it be 3 quarts low, with no tranny fluid leaks.

 

It could be leaking into the transfer case. Take the fill plug out (top one) and see if fluid comes out, if so that's your problem. Transfer case removal and new seal. Or monitor it if its not to bad. If not kept up on this can cause problems with 4wd and heater vents

 

^^ Yup, I agree. Will definitely cause problems with the transfer case if it's the 4 button, Auto 4WD, (it uses a different fluid).

 

ive seen thisissue with a few S-blazers, my current one included, i took out the top plug of the transfer case ans 4 qts came out, more than the transfer case is even supposed to hold! $12 seal, not too bad to replace, just time consuming, good time to replace the fuel filter too, as its alot easier to get to with the transfer case out of the way. you'll want help putting it back in. that thing is heavy and awkward to handle. you will also want a new gasket between the trans and transfer case. forget what that cost me, had to get the gasket from a stealership.

 

If it uses the radiator to cool the fluid check your antifreeze, I don't know if the zr2 has an external cooler. I had this happen a long time ago on another car were the fitting/coils for the trans leaked internal to the radiator.

 

i think every auto trans 4.3 blazer has a trans cooler in the radiator.

 

Yup, and they're about worthless.

 

agreed! I capped mine and installed a external one,

 

Do you really need one if you don't tow or is it just a good idea to have one?
Also on the OP problem could it be the modulator? Seems I once had a car that did this and that was the problem.

 

Definitely need a cooler of some sort, even if you don't tow. I do the same thing on all of my vehicles: Install a heavy duty aftermarket cooler in front of the radiator and totally bypass the cooler in the radiator. A leaky diaphragm in a modulator could definitely cause trans fluid consumption however, the OP's vehicle has a 4L60E transmission, no modulator valve. Shift points are determined and commanded by the PCM, all electronic.