03 g35; ~50k kms. (it's been 0* to -30* the last little while, so I can't comment on engine over-heating because, well, I doubt it would in these temps, lol)

For the last several weeks I noticed that I almost never got any heat when the heater was on. Couldn't figure it out. I looked at my coolant today, and i lost about 1ltr worth (it was wayyyyyyyyyyyyyyyy below the min mark; and took about 1ltr to fill up 3/4 of the way between max and min)

I havn't noticed any leaks on the ground or white smoke (other than the usual for our current temps). havn't changed the oil yet so I can't say anything about what's going on in there, but if anti-freeze is disappearing and you can't find a leak, that's probably head gasket, no?

 

Added some anti-freeze, forgot to mark where I filled it up, so I'm not certain if it's down or not, but when I driving, without any heat or ac on, all the windows are steaming up like crazy.

I remember reading something where if your head gaskets are almost shot the inside will fog up?

I reallly need to get it on the oil and change the oil and see what I find I suppose., but I'm just curious if anybody can confirm the above?

 

dotn't forget to put fully synthetic oil!