I just put in a little coolant in my mercedez class 2005 it's not starting now why?

In the coolant recovery tank. You do not use water you use coolant, a 50/50 mixture

if you hear the starter engage but engine does not revolve with a known fully charged battery-you may have a leaking head gasket causing a hydro-locked engine.

look close at your expansion tank. you will find marks
max____
~~~~~~~~~~~~~~~~
min_____
after you drive for 5-10 min.the coolant expend and rise the level in the tank
fill the coolant to max on cold engine
DON'T MIX COOLANT
USE ONLY FACTORY RECOMMEND

PENTOFROST SF (without silicates)
(Formerly LIFETIME ANTIFREEZE G12)
Size: 1.5 liters (1.59 quarts), Part# 8114107
Color: Pink & Clear
CLICK HERE FOR PENTOFROST SF SPEC SHEET

• Audi (after 06/1996 up to 2005); Spec. TL 744 F

if its ready mix solution just buy 2 gallons and fill the rest up with water I think off hand its around this much I buy the water down type I put a 5 liter or 1 gallon in and top the rest up with water don't worry about putting to much in what doesent get used goes out of the overflow pipe hope this helps ivan

When engine is cool, take off radiator cap, and fill radiator. Then fill the coolant recovery container to halfway between the full cold mark and the full hot mark. Start engine (with radiator cap still off) and wait for the thermostat to open (upper radiator hose will get hot). Shut off engine, top up radiator, and put the radiator cap on. Fill the coolant recovery tank to the full hot mark.
You should mix the water and anti-freeze in a 50/50 mix before putting it in the car, you know. Cheers.

It is best to add a coolant mix. You can get it ready mixed, but try to ascertain if your car now has in it green mix or red mix. It is best not to mix these 2 mixes LOL
If you cannot make out what is in there now, just add demineralised water.

The coolant can be found at most stores that sells automotive products. You will need a 50/50 mix of water and coolant. If you had drained you old coolant you can purchase premixed cooland were no water is added. I would purchase two gallons of cooland for you vehicle and change the thermostat as well

if the rad has no cap then there should be an external expansion tank, with a small water pipe running to the rad, this circulates the water, make sure you dont get confused with the windsheild washer tank, may sound silly but has been done lots of time!

open the hood in the front of the car when the engine is cold only remove the radiator cap start the car and fill it up the engine will get to its running temperature when its full put radiator cap back on there it is thanks pierre