I recently had a coolant leak issue (as was evidenced by a constantly returning puddle on my garage floor). When I got around to looking for it, I quickly found a bunch of residue on the outside of the coolant reservoir and on the engine below it. There were also some tiny cracks in the reservoir. So I ordered a new one. While I was waiting on the new tank, I had to refill the reservoir a few times, but it was only a little every few days.

However, since replacing it last weekend, the problem has worsened. There is no visible puddle anymore, and no obvious signs of leakage anywhere on the top of the engine (I haven't crawled underneath the car to look there yet), but the amount of coolant I'm having to add has increased dramatically. On my 35 mile drive to work, I lose nearly an inch of level in the tank. There's no white smoke, loss of power, frothy oil, or other obvious signs of cross-system contamination. But I have used nearly a gallon of coolant/water mix since last Sunday. So obviously it's going somewhere.

I didn't notice when I ordered the tank that it didn't ship with a new cap, so I put the old one on the new tank. Now I'm wondering if all this stuff is evaporating out from under the cap while I'm driving. There's lots of condensation on the inside of the tank when the engine is hot. Does this sound plausible? Could that much liquid be escaping through the cap? Or should I keep looking for other culprits?

Thanks in advance for any help you guys can give.

Jeremy

 

?? secondary water pump maybe??

 

You get the cookie! Sorry, I forgot to close this thread out. Yep, it was the secondary coolant pump. Glad I didn't drive it anymore than I did either; the end of the pump disintegrated when I touched it and drained all the coolant out of the system above it. It was beyond failed.

 

Glad to hear you caught it in time.