Take the 2-minute tour ×
Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. It's 100% free, no registration required.

I have a 325I 2003. I wanted to put coolant in my car and I started putting it in the reservoir. But I wasn't sure if that is where i put it so I stopped. Will it hurt if I put a little in the reservoir and if the needle in the radiator is already top-off should I wait till it need some. A friend of mine did some work to the car and he said the water was really low. So for a temporary fix he put water. But told me that I needed coolant.

share|improve this question
add comment

2 Answers

The first thing to do is repair any cooling system leak that you have. (Only on a cold engine). The filler cap is on an expansion tank, which is on the right hand side of the radiator as you look at it from the front of the car. You add a mixture of antifreeze and water, at a 50-50 mix, into the tank until the float in the tank rises to the top. Replace the filler cap firmly. Run the engine until it is warm. Next to the filler cap is a cross headed plastic screw. Loosen this screw slowly until you hear air escaping. Do not unscrew this screw fully out. After the air has all escaped, coolant will start to come out of the screw. Tighten the screw back up. The cooling system is now full. A final check would be a road test to make sure the temperature gauge, heater, and cooling fans are all working correctly.

share|improve this answer
    
if i put some coolant in the reservoir accidently does that harm anything? –  user4087 Dec 4 '13 at 18:49
1  
@user4087 Fret not! The coolant overflow tank (aka expansion tank) is the appropriate place to add coolant. –  mac Dec 4 '13 at 20:49
add comment

Since your friend added a significant amount of water to the system it has diluted the mixture of coolant to water. Instead of just adding coolant you need to drain the system and replace it with the correct ratio of water/coolant.

As Allan hinted at, the only way the coolant would be low to begin with is a leak somewhere. Unless that is what you friend was repairing you still have a long term problem that will need to be addressed before it causes your engine to overheat.

share|improve this answer
    
if i put some coolant in the reservoir accidently does that harm anything? –  user4087 Dec 4 '13 at 18:49
    
Nope, that reservoir should also be filled to the points marked on the side of it. –  jzd Dec 4 '13 at 18:50
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.