The fluid level light keeps coming on. Doesn't need a water pump, already checked. Replaced a cracked reservoir. Hoses okay. Smell antifreeze after driving. Also, CO2 sensor ok. Churns when starting. Starter ok, said its not the fuel pump. Any other ideas

Can you physically see it leaking underneath the vehicle? Or is it condensation dripping out from your air conditioning? If you just smell it you may have a blown head gasket. How often are you adding fluid to the reservoir?

A flashing red temperature indicator means your fluid level is low. The 99 beetle takes VW-specific antifreeze; do NOT buy standard green antifreeze for it! Fluid should be added to the round overflow bottle located on the passenger side corner of the engine compartment. Fill the container to the MAX line indicated on the bottle. I use Pentosin Pentofrost SF in mine, available at O'Reilly Auto Parts. As with most antifreeze products, mix it 1:1 with water before adding.

Cars do not normally "use" antifreeze, so if you keep having to add antifreeze, you should check for leaks. Heater hoses or radiator hoses are the most common places for leaks to occur, but the plastic thermostat housing is susceptible to cracking, so check that as well. Otherwise, you could be looking at a leaking radiator or heater core. Worst case scenario would be a leaking head gasket allowing fluid to escape into the cylinders, but that should be suspected only after everything else has been checked. The only other place you would ever see a fluid leak would be a bad freeze plug on the block, but those are very uncommon.

Look at the area where you park. Is there any fluid under the car that is not oily but rather is slick and has a sweet smell - yes, you wil have to stick your finger in it to see. If you find this type of fluid, you have a leak from somewhere in the engine compartment. Judge by the amount of fluid whether this is a major and potential calamity. (Lots of antifreeze could mean a bad hose or a bad water pump.)

Once you've checked for leaks, check the plastic reservoir that holds the radiator coolant overflow - is there anything in it? If you found alot of fluid on the ground, odds are that the reservoir will be low. If it is much below the fill line, add some water and coolant (50/50 mix) until it is back to the fill line.and check it for awhile to see if it needs more after you have driven for a bit (keep the coolant with you in the car just in case.) When the engine is cold, and as you are checking the reservoir, remove the radiator cap by pushing down on it a bit and turning it in the direction shown on the cap itself. Look into the radiator with a flashlight to see where the fluid level is. If it is more than 2 inches from the top, add a bit of coolant/water but not up to the top. Replace the cap firmly and add coolant/water to the reservoir cold level mark.
If that all looks fine, you may have a bad water pump, a plugged radiator, a week cooling fan or a bad thermostat.

Good luck.

First you should check your antifreez level , check your water pump and thermostat also check the intake gasket , this car has intake gasket problem all the time , if it your intake gasket then I woul repair ASAP before it leades to head gasket , which is more costly . My recommandation to you is to check the fluid level and start the car and turn the heat on all the way , there are two bleeding valves on the tops if the engine from the righ and the left radiator hoses near engine side they are 7mm open them and keep adding antifreeze Untill the fluid come out clear of bubbles from the bleeders , close bleeders and check your heat .
Caution , fluids may be extremely hot do please becareful . Good luck .

chk to see if both cooling fans come on when temp gets high, chk fluid level, check for cracks in antifreeze reservoir. look for leaks under car ,
like under water pump. throw in a new thermostat for good measure.

Stop me if this has NOTHING to do with your problem (or if it's already been solved)...I don't know a lot about cars so...My Ford Taurus kept overflowing antifreeze from the reservoir cap. Car started to over heat and kept spilling"/dumping" antifreeze every time I turned the car off. The antifreeze reservoir had been replaced less than a year prior, and water pump, radiator, etc looked at. I got a free estimate that stated my water pump was NOT the issue, but I did need a new radiator and my reservoir tank needed to be replaced (again)....$800 parts and labor.... However...I noticed the overflow holes on the tank, and also that the orange liquid (antifreeze), was also spilled around the cap lid. I also noticed the CAP on the antifreeze reservoir would loosen when tightened completely- hence, not sealing correctly. So I went to the dealer, bought a new reservoir cap for $15, replaced it, and never had an issue after! I also found out that the CAP was a DEALER PART ONLY, and when the tank itself was replaced, the CAP was the OLD one! Problem fixed! Maybe it's similar? Or something "more serious".

check the passenger side carpet and see if it is wet.. if so then your heater core is leaking into your car and you need to have it replaced. If you do not see any leaks there then check under your hood with a flash light and look for a green liquid and see if you find any leaks... usually check your hoses and under your water pump also check your radiator and coolant reservoir level. Good Luck Friend

Are you losing coolant?

On the under side of the water pump there is a hole called a weep hole its there to let you know that the seal is leaking on the pump and will need to be replaced soon so you don't have a major failer on the highway and damage your engine

replace your radiator cap.