I have been losing a little coolant, about half the full to low mark on the expansion tank, over the period of two weeks or so. The usual coolant smell isn't there and I don't see any under the car. The hoses seem fine, but I haven't checked too thoroughly yet. I was looking under the hood while the engine was still warm and heard a slight hissing sound from the expansion tank cap. If the system is supposed to prevent coolant loss through evaporation with a pressurized system a slight leak could allow water vapor to escape resulting in coolant loss. I'm guessing that the coolant has a higher boiling point so the water would evaporate first, thus no coolant smell. This could also result in the wrong balance between coolant and water. Could this be the source of my leak, or is this just wishful thinking? I hope not as this is about 8 bucks to fix.

Thanks again for the help. I can't exactly return the favor with Volvo help, but if you need some help with statistics or research let me know.

 

Thats using the ol' noggin. Great first step. I think you're right on with your assessment. Thats great that it might be a cheap fix as well. If its the cap hissing, you could confirm it if you have some teflon tape handy. That's just something that I would do since I'm lazy and it would only take 10 seconds, but obviously not a permanent fix. Anyway, just wanted to give you the thumbs up on the detective work.

 

I agree, sounds like you are in the right direction. For $8, I'd try it out.

What type of stats - can you help me with my homework on the Mann-Whitney, Wilcoxon Signed Ranks, and paired-t tests? Actually I can handle it, but I was curious since I happen to be taking a class on stats right now.

 

That's the stuff. Undergrad or grad school?

 

Grad school - Systems Engineering.

Btw, I like your quote. I considered doing a paper on Kurt Vonnegut at one point and even borrowed a few books of his from the library. I couldn't decide on a topic though and changed it midway through.