4runrjunkie

Hey everyone,

I am hoping to get some input on my 3vze because it is currently frustrating the heck out of me. About a month ago, I noticed I was starting to leak some coolant down the back of the motor. I was pretty confident it was the bypass tube (i think that's the common one) or the valve leading to the heater core. It wasn't an excessive leak by any means, and so I just kept an eye on the coolant levels and figured I would fix it when I had a more forgiving balance in my bank account. This was all working out well until I came out one morning and had a giant puddle under my car. I checked my rad and couldn't see any coolant in it, so was pretty sure whatever was leaking had given way over night and had drained it all out. I decided to fill it back up, burp the system to get any air out, get it up to operating temp, and then try and find the leak. Here's the problem though, it held the coolant level perfectly fine! No leak anywhere to be seen. I was thoroughly confused to say the least. It held solid for about a week and a half, then a couple of days ago I started to notice the little drip mark was back underneath the truck (maybe two inches in diameter over night). I figured I would get back under there this weekend and check it out, but last night it completely drained again. I filled it up, burped the system, got it up to operating temps, and once again there is not a leak to be found

Long story short, I want to know if anyone has experienced this before, or could maybe point me in the direction of what could be causing this. I can deal with a slow leak, and I can deal with a catastrophic leak repair, but not being able to find where the damn leak is coming from after a catastrophic leak is really getting annoying.

Any input would be greatly appreciated. Thanks!

Gevo

Well, can you give any more information about what you have done to try to figure out where the leak is and what you saw? There are many hoses, even in the back of the engine bay. Check your sensors on the bypass... There is one that is a valve based on the coolant temp, if the membrane in there is messed up that could cause a leak. I can't remember if it's normally open or closed. Also, do you have rear heater? is this 4 runner or truck?