normal coolant loss ???

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Mar 7, 2009
my friend has a 2007 buick lacrosse with the 3.8 v6. anyway he likes to monitor his coolant system with all the dexcool nonsense. so since he started monitoring his cold level in the reserve tank,every week or so before inital start up after sitting all night.

He just had to add 3.5 ounces of dexcool to bring it up to the cold fill line. So would this be considered normal coolant loss in a 5 1/2 month period with 5500 miles placed on the car during that time?
I always thought that no coolant loss is considered normal.

That said, my 2001 Regal with the 3.8 V6 (series II vs the Lacrosse's series III) loses about twice that during the same time period.
There are only two times where I have had to top up coolant. First is any time I have done cooling system service and allowed air into the system or on a few vehicles when it gets -30 some of the worm gear clamps will loosen up on the fitting. The fittings with constant tension clamps have not had the problem.
I keep having to add a little bit of coolant now and then in my car as well. Not sure where it's going. I probably add twice as much as your friend does.
Normally you shouldn't have to add fluid to any part of your vehicle. If you do you either have a internal or external leak.
Oil and anti-freeze (coolant) can internally leak into the combustion chamber. I would say that if you are regulary changing the anti-freeze out when your suppose to..every two years or so you shouldn't be considerably low on fluid.
Adding coolant that frequently means it is leaking it somewhere. I would have the system pressure tested, and possibly a UOA done. There could be an external leak, that is hitting something very hot and boiling off, although you'd probably see it, or it could be an internal leak, either way there is a problem.
My 2002 Sentra does the same thing. I have to add just a little antifreeze every time I chnage oil. Took it to a mechanic who pressure tested it and said one of the hoses was leaking around the clamp. The replaced the clamp. Seems to have helped, but seesm to be leaking somewhere very,very slowly.

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Coolant evaporates. It gets very hot, and evaporates easily out of the puke tank.
How much? Maybe add a bit once or twice a year with an otherwise good system.
And don't forget that as it's temps vary, so does the level.

Systems with a sealed pressure cap should not lose any.
I would have to say, is 6-7 ounces a year really a loss? or normal evaporation and useage. it's not a completely closed system. Also doesn't the service manual suggest you check your levels and add as needed?
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