Hey there, I'm new lol. Recently bought a 1999 chevy monte carlo from a trusted dealer, had about 125-126k miles on it (low budget). Had an oil pan leak which was fixed, but now the coolant in my car goes down way too fast. On a full tank of coolant, it's just about gone in a few days. There is no obvious signs of leakage on the ground either, and my tail pipe does blow white smoke, light white like from a cigarette, but that's only during cold nights which I figured was condensation. I checked my oil dip stick and there no signs of rainbow color or white blob color so I don't believe it's mixing with that. There seems to be something leaking on my AC compressor (AC doesn't work at all anyway, the AC liquid drains in about a day or two, it's been empty a while), and other places. I can't seem to figure out what the problem is.

 

start the car in your driveway, let it run for a good 30 mins to get warm and go through a few cycles of the thermostat opening and closing. do you notice the sweet smell of coolant burning off?

then shut off the car and let it set there, do not drive it.

once its cooled off, do you see coolant on the ground anywhere? should be pretty noticeable if there is.

i would suggest putting a cardboard box under the car so you can see the wet spots

 

Check around the coolant elbows that go into the tensioner pully... There usually the first to fail. Itc ould also be time for upper and lower intake gaskets.... also checkand see when you remove the oil fill cap for what looks like a "MilkShake" coloring in the valve cover and on the oil cap itself... Could be sucking the fluid right either into the oil and mixing with it and also out of the exhaust as well..Its an unfortunate occurance with our Monte Carlo's I'm guessing you ave the L36 3800 series II motor correct?

 

the milkshake on the oil cap really isnt indicative of an issue especially this time of year. if it were summer time or warmer weather, i would agree. but moisture does collect in the valve covers during the winter. the key is if the milkshake is on the oil dipstick then you have an issue.


my hunch with the leak showing on the a/c condenser is that if he has the 3100, then its most likely a failing water pump