Losing coolant, but where from?

[kris]

I've been losing coolant for a while now, but quite slowly. As in, ive had to top off two or three times in the last four months because my dash told me it was low. I haven't had an issue with overheating, I just had an inspection a couple weeks ago and emissions were lower than last time on all counts, I haven't noticed any smoke, no coolant in my oil or oil in my coolant, no leaks that I can see, and I believe the water pump was replaced 25k miles ago during the engine rebuild. I will add that the engine rebuild was done by my cousin (very capable) but on my uncles budget, who wasn't planning on keeping it long. The first thing I had to do when I got the car was scrape rtv off the valve cover to replace the gasket.

[TXSaturn02]

If you are on your original radiator, you are due. A slow leak (in the form of steam) will develop in a crack (from what I've read here on many posts) in the radiator. If in the form of steam, in a small crack, you wouldn't notice it dripping anywhere. The crack will continue to get larger.

[flyhop]

A bit off topic, but how would one notice/find a small crack in a radiator? Do you hear a hissing sound, or see a tiny jet of steam? Do you pressure test the system and wait for a drip out from below the radiator? Look for a wet stain under the radiator in the morning?

Just curious.

[TXSaturn02]

Originally Posted by flyhop

A bit off topic, but how would one notice/find a small crack in a radiator?

Just curious.

If you search, you might find some pictures from people who have posted pictures of the common area the crack usually starts. I can't remember exactly, but have a general idea - I believe on the driver side.

[madpogue]

Originally Posted by flyhop

A bit off topic, but how would one notice/find a small crack in a radiator? Do you hear a hissing sound, or see a tiny jet of steam? Do you pressure test the system and wait for a drip out from below the radiator? Look for a wet stain under the radiator in the morning?

Just curious.

Cold pressure test.

[Signmaster]

The common radiator crack is on the drivers side, right where the lines from the transmission enter the radiator. Even if you have a factory 5 speed, the leak is in the same area, just no transmission line enters the tranny.

The crack will start hardly noticed unless the radiator is at max temp/pressure. Even then they start very slow, and might only leak a few drops now and then. This slowly increases. And even an ounce or so of lost fluid adds up when you factor in all the drive cycles in a few weeks or a month.


In the end, the only way to confirm or deny a leak is to get everything clean and dry, start the car, and find the leak. There are a lot of places coolant can leak, but without finding the leak it's just a guess.

[madpogue]

Originally Posted by Signmaster

In the end, the only way to confirm or deny a leak is to get everything clean and dry, start the car, and find the leak.

No, it's not. The whole point of a cold pressure test is to find a small leak by making it leak as a liquid and not a vapor.

Speaking of which, a failed reservoir cap is another prime suspect.

[Signmaster]

Originally Posted by madpogue

No, it's not. The whole point of a cold pressure test is to find a small leak by making it leak as a liquid and not a vapor.

Speaking of which, a failed reservoir cap is another prime suspect.

True enough. If you have a pressure tester, it should find anything external.

[screwpid]

Mine sometimes leaks beacuse of the old clamps. Go to home depot and get some new steel clamps. If you got those old oem squeeze clamps, they got to go.

[Saturn2002SL2]

check the plastic part of the radiator on top by the seems. The seems might be cracked like mine...

[kris]

With how many different places I'm having recommended to check, I think I'll just start with a cold pressure test. Though with no income and a car that needs registration, tires, an oil change, a motor mount, and something else that's not coming to mind at 2am, I think this slow coolant leak will be put on the back burner and checked regularly. Thanks guys!

[BIGGUNDOCTOR]

I found a small slooooow drip on mine at the base of the radiator in the fin area where it is exposed to rocks, curbs, etc, and may have taken a hit. I do the same, add water when the dash light shows.

When I first bought the car I was losing fluid, and found a small spring on the radiator cap had turned sideways. Took my pocketknife, and flipped it vertical again, and the leak stopped.