Topping off Coolant

Topping up every six months isnt so bad. Just depends on how much you are having to add each time! I tend to drive older cars (over 10 years) so am used to topping up coolant from time to time.

coolant reservoirs can be a bit deceptive. The min max refer to levels when the coolant is cold. If you fill to a certain level when the engine is warm, close the cap etc you will find the level has dropped again as the coolant contracts. To see if it is dropping, check when cold, then add fluid and check level again once engine/car is completely cool again.

Further, small fluid leaks can be a cause of gradual coolant loss and unfortunately can be tricky to find. Often easier once they have been going for some time and the colourful antifreeze crystals can be seen.

Small slow leaks can leak more fluid that you might expect. My 960 had a tiny fluid leak from the thermostat housing. Coolant was dribbling very slightly over the housing. On inspection, it looked like a tiny spray of water. The area was only slightly damp . However, it was enough to loose about a litre of coolant from the expansion tank over a few days.

I'd think you are more likely to have a small leak somewhere. The most extreme cause of coolant loss is the head gasket. Pressurising the coolant system and seeing if it holds pressure may indicate a leak somewhere but it wont differentiate between a small hose seeping fluid and a small HG fault.

Also, the "acidity test" of coolant to check for headgasket failure is also flawed if the coolant is anything but new or well within its service life (from 2 to 5 years). Anti-freeze contains a lot of additives, anticorrosion additives and anti acidity additives. Ethylene glycol (main part!) oxidises in air to form acids. These need to be countered to protect the metal of the engine. The "exhaust gas in coolant" check also checks for acidity and can be mis-leading as it can simply detect the acidity of old antifreeze.

I think white smoke from the exhaust might be more indicative of coolant loss via the head gasket.

Re: (phuz)


Coolant is delicious Keep it comin!!!

On a serious note... Could be the start of a headgasket failure that just hasn't surfaced as a problem... yet ! It could explain why you don't see a leak... A slow amount of coolant going into 1 or more cylinders would just evaporate and be blown out the tailpipe yet not enough to cause anything too noticable as far performance loss. What is the longest you have let your car just idle over a dry surface? Last go to any competent autoparts store and mention that you are looking for a florecent fluid to add to the coolant tank to identify a leak, and they will hook you up. Then go get a few black light bulbs (or any UV producing light) and swap out you standard incandecent bulbs in your work lights. The stuff is amazing, it has helped me identify numerous coolant and PS fluid leaks. http://********************/smile/emthup.gif Any other issues? Good Luck... By the way... Phuz is right: Not Normal

Re: (BeerEngineer)


Amazingly enough they sell distilled water at just about every grocery store in handy to carry 1 gallon jugs.