Disappearing Coolant

[mduff]

I'm a new '99 996 owner and am a little baffled currently with the coolant level. I drove the car home after purchase nearly 1100 miles from Miami. No coolant issues. Then after typical around town trips I noticed the instrument light flashing indicating lower levels of coolant. Top it off and drive on. Two weeks later the same thing but this time, I needed to add almost a full liter! The entire time the temp stays within acceptable range and no stains or pools of fluids anywhere to be seen. I have looked under the car on a limited basis but it all looks very dry. Any known coolant drinking TSBs out there?

[Loren]

Yes, the cap was changed and the new part number should end in 01.

There have also been at least 4 coolant tank designs due to cracking. There is a DIY here to change your coolant tank if needed.

A third possibility is that coolant is getting into the your oil (not good). Chances are it is one of the first two.

[JimPDX]

I'm a new '99 996 owner and am a little baffled currently with the coolant level.  I drove the car home after purchase nearly 1100 miles from Miami.  No coolant issues.  Then after typical around town trips I noticed the instrument light flashing indicating lower levels of coolant.  Top it off and drive on.  Two weeks later the same thing but this time, I needed to add almost a full liter!  The entire time the temp stays within acceptable range and no stains or pools of fluids anywhere to be seen.  I have looked under the car on a limited basis but it all looks very dry.  Any known coolant drinking TSBs out there?

<{POST_SNAPBACK}>

Mine did the same thing for about a month. The coolant light never came on , but I noticed a drop in the coolant level. Did a post on this board and someone suggested that maybe I had a slight coolant leak from the expanision tank. I noticed no leaking whatseover, but i did ocassionally notice a coolant smell after driving.

I was told to look at the muffler pipes and tail pipe driver's side after a drive bringing engine up to speed. You do this from under the car to see if there was any coolant residue like drips of coolant onto the pipes. Sure enuff there was. The coolant would drip down onto the pipes and evaporate off creating the coolant smell thats why I never saw any coolant under the car but you could actually see the coolant dribble marks on the pipes.

Replaced the tank and got a new coolant tank cap. No smell. Coolant is fine now and maintains its level