Where's my coolant going?

[jordanGT]

Ok. 2000 Grand Am GT. 63,xxx miles. Suddenly a couple weeks ago I noticed I was low on coolant. No visible external leaks. I don't know if it's related or not, but I also use about a quart of oil ever 2,000 miles. Is this just normal aging car stuff or would you guys think I have a gasket leak or something? Thanks.

[Mazz]

Does the oil have any milky color to it? Does the exhaust smell sweet or like antifreeze? Could be a head gasket. If so, get your wallet out.

[rabidpanda69]

Or the lower intake manifold, look into it ASAP, coolant is the last thing you want in your oil.

[kickarsgrdam01]

my vote goes to the lower intake manifold

[nice96gt]

Unfortunately...coolant doesn't just "disappear". Check your oil first and then go from there.

[RocketMan]

What happens is you get a small pressure integrity failure in the intake plenum gasket, which causes small amounts of coolant to run down the block and vaporize...which is why there's no trace of a leak. Other possibility is head gasket leak in which case your coolant is likely seeping into the cylindars and getting burned off with every cycle. Quite common with this car I hear.

[sunrunner_pei]

This recent thread has lots of info to help you on your way:
http://www.gaownersclub.com/forum/showthread.php?s=&threadid=51654&highlight=lim

[rixGAphx]

I would consider these as two different problems.

1. Disappearing coolant in a 3.1/3.4 is common and expensive. I agree with all the above responses on this issue.

2. Oil consumption: Your engine is 5 or 6 years old, so about 75k miles?
A quart of oil every 2000 miles is unusual, and of course bothersome and a waste of money.
Oil consumption comes from 3 sources:
a. Drips/leaks: Since you didn't so state, I assume there are no major signs of this.
b. Internal 'blow-by': Warn rings (or sometimes, a single broken ring) allows too much oil/oil vapor to come up from the crankcase.
Also, a plugged PCV valve can allow crankcase pressure to get so high that oil vapor is FORCED past even good rings.
c. Oil Seals: Chevy 350's are famous for this, but the 60* head design has never had a maor problem in this regard. Mebbe GM learned from its mistakes?? Naw.

Anywho, even a brand-new engine right off the showroom floor will consume a LITTLE oil (half pint between 3000 mile oil changes?).
I have heard of dealers weaseling out of warranty responsibility for a QUART every 3000 miles when new!

Change that PCV valve, and have a compressison test (including leak-down, which is another related procedure) as a part of the coolant leak investigation.
This will reveal if one piston's rings are a problem, or mebbe the entire engine is just overly-worn.

Good luck.
-Rick