My coolant was rather low today, as you can see by my other thread here in tech. I hadn't checked it in months or anything; but how much use is normal? Does it slowly evaporate out of the system or do I perhaps have a slight crack in one of my heads?

I've never seen white smoke or anything. Just curious.

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Nobody likes a loser, be a cheater.

Shouldn't be using any. It's supposed to be a closed system. Check your radiator cap, odds are you have the wrong one (The one in the books -all the books- is the wrong one) You need the one with the extra spring on it.

You shouldn't lose much coolant, however in warm climates it might be possible to lose some by evaporation. Not checking it several months and only noticing it a little low shouldn't indicate any problem. Usually I have to add coolant to the overfill tank about once every couple of months but I think thats more related to the fact that the tank is cracked noticable at the top and possible further down. Otherwise I have no leaks, new thermostat and radiator cap, and the engine/head are crack free.

I'd replace the front cap if it's old. The rear one probably could stand to be replaced too, but it may not be quite as critical since it's the highest point in the system.

If you keep losing coolant, something is wrong.
(At one point, I was getting about 15 miles to the gallon of antifreeze. I'll spare you all the gory details.)

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Raydar

88 3.4 coupe. In progress.

Out of my mind. Back in 30 minutes.

I surely agree with replacing the caps! Also, there are many places that coolant can "seep" out without really leaking noticibly. Replace the caps and keep a check on it. I check mine once a week usually. Good luck!

Phil

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87 FIERO GT 2.8 5spd
0-60 in 6.8 seconds!

You likely have a slight leak someplace. A likely culprit is the heater core in many cars. Weepy hose connections are also very common.

Mixed coolant has a pretty low evaporation rate. If the cap on the catch tank is in place, even if old, evaporation should be nearly nil. Doesn't hurt to repair/repace the catch tank cap. (Usually the cap is good but the gasket has rotted away.)

I always recomend people replace rad and thermo caps as a set. It's cheap insurance.

Also. Read my cave article and make sure you install the correct Front cap. Most parts books list the wrong Stant cap up front. Using the wrong one will cause trouble.

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RIP Crew of Columbia. 01-Feb-03