have a 97 caravan 3.3 v-6 that is losing water somewhere. has gotten so bad that it loses almost a gallon just driving about 20 miles. has no water in oil, no oil in water, no air bubbles in radiator while running at normal temp. this thing has no drips underneath, or anywhere. never steams from under hood after driving. have checked all hoses, and there is no water leaking from water pump weep hole. can see absolutely no signs of a leak anywhere. motor has never overheated since we have had it(almost 6 yrs). motor doesnt miss. seems to run just fine other than drinking lots of water. i can find absolutely no sign of water leaking anywhere on motor at all. have heard of headgasket being blown on outer edge causing water to leak to outside of motor. but losing this much, would surely see a leak, or at least steam from somewhere!! anyone have any ideas at all? this thing is driving me crazy, and i cant afford any more grey hairs![>:]

 

First do a cooling system pressure check and look for leaks while the system is under pressure. If you have a leak that's spraying, you might not notice it when the car isn't running. Plus, if it's losing pressure while the engine isn't running, you can sometimes use and automotive stethoscope to listen inside the intake manifold for a pressure leak.

You can also pull the plugs and look for a plug that's cleaner than the others. That would indicate a head gasket leak. If you find one, repeat the cooling system pressure check and insert the stethoscope hose into the plug hole. Also do a compression check.

 

we have let this thing set in the yard and run for hours, and checked it while it was running, and checked it after turning it off. still no water. if it was leaking internally into intake manifold, wouldnt it be putting white smoke or steam out tail pipe? no moisture except for the normal condensation coming out exhaust. no smoke or steam at all. i have crawled under this thing with it running at operating temp. and no sign of water at all. have shut it off and checked again, and no sign of water at all. plugs were changed not long ago, and no abnormal discoloration on any of them. all looked the same.

 

Well this is a stumper! One other spot that coolant can be lost is across the transmission cooler within the radiator--have you checked the trans fluid level?

 

transmission fluid is full, and normal red color with no signs of water. a water leak this bad, surely i could see water dripping or spraying somewhere, and if it was internal, shouldnt there be lots of bubbleing in radiator while running, or white smoke from exhaust? I have neither one!!

 

I had a similar thing happen on a 93 dodge dakota (318) happen to me. Turns out the top header for the radiator was weaping under the cap area. I couldn't find it running it because it was very slow---but constant. I finally found it doing a pressure check of the cooling system using a regulator and cap that has the pressure relief lever back into the overflow hose. You also might want to check the overflow bottle. Sometimes they crack and slowly leak out, or the overflow hose.

Just some ideas

 

Since all this beagan have you filled back up with antifreez? I had a similar problem on a caddilac, drank water and no leaks. I filled it back up with antifreeze and the leak became apparent. The antifreeze would put white smoke out the tail pipe as the motor sucked it in via a bad head gasket. The caddy ran fine, would just drink all the water and overheat in 20 - 30 miles. Too bad it was a nice caddy, but not worth wrencing the head( if that's all it was )

RIPol' caddy

Joe

 

do a pressure test.. and a die test.. they make die to put in the radiator... fill up with a/f and die.. let run for 20 min or so.. if its that bad.. maybe a little longer... put on 'special' glasses and use a blacklight.. if there is a leak.. you will find it

 

have not done a pressure test yet, but did fill everything up, and parked on a dry cardboard(no luxury of concrete)and noticed a drip under filler neck. checked, and around mounting bolt bracket is wet, looked at passenger side, and is wet same place, running down and running across lower valance. will do dye and pressure test next. have just been running water for a while now, but was leaking back in winter with antifreeze in it, and noticed no white smoke out exhaust, and always smelled of antifreeze under hood, just never could find anything. maybe just same leak got worse over time, and finally showed itself. dont think it is head or gasket(hopefully). has never run anywhere near hot since owned. always runs at middle or just below on guage. am i on the right track???

 

Yup,
Sounds like you're on the right track. Check the filler neck for any possible cracks, and the connection for the overflow tube for a small crack. The pressure check is really the right way to go.