My Altima has a coolant leak near the engine and I was wondering if someone can help me ID. what/where the suspected culprit is. I tried taking my car to a mechanic but he passed it off as past residue that was not cleaned up well enough, in other words, quick checks are pointless. My Coolant reservoir fell from Max to near Min in just one month.

Here is all the information I know.
- I can see the residue only in the morning time (7 to 8am), but not after work (4 to 5 pm), when I drive home. Temperature variation is 40 deg F to 75 deg F.
- The engine evaporates the coolant every time so it looks like nothing is wrong
- I suspect it is coolant, because it is green.
- Every day I check under the car, there are no signs of coolant on the ground
Here are some shots I took of the exact positioning of the leak
http://imgur.com/gQP5w26,hnuv5dj,5OwaSyb#0
http://imgur.com/gQP5w26,hnuv5dj,5OwaSyb#1
http://imgur.com/gQP5w26,hnuv5dj,5OwaSyb#2

Here is one with me highlighting the coolant sighted area
http://imgur.com/AjGJApA

I will try to jack my car up tomorrow to see if I can get a better view, (and take more pictures) but does anyone have an opinion of what is on the right side of the engine that could be coolant related?

looks like it's where the thermostat is. have you recently replaced it? and to make sure it is leaking and see exactly where, get a coolant pressure test kit. that will reveal some answers.

I have some more pictures,

The underside, from drivers side taking the shot. Not as helpful as the top view I think
http://imgur.com/8DLPj20,Fb2xbOi#0
http://imgur.com/8DLPj20,Fb2xbOi#1

I will try looking at the thermostat, Thanks Gambit

no problem man. just make sure when you go to put the thermostat back in and seal it up, use a silicone agent for the housing to seal. just don't get it on the thermostat itself. you figure they would come with gaskets, but nope. at least when i got my new thermostat it didn't come with a new gasket. good luck dude

http://imgur.com/qPL9Ug7

I used LC-13 of the Nissan altima FSM as a guide.
I do not think the culprit is the thermostat or the water outlet connection. The thermostat is too far away and I cannot feel anything wet/grimey along the water oulet line. Are there any other places the coolant would go through at that spot?

is there any evidence of coolant residue above the thermostat? as for the housing, it could be a slow leak to where it's riding on the lines to a different place all together. i just recently figured this out with a fuel leak issue i was having. i'd try it just to be safe and if there's still a leak, then pressure test the coolant system. the pressure test will really help you in determining the relative, if not exact, location.

i'm assuming the pink arrow with the circle is what you're referring to. and it looks like the cyl.4 exhaust port off the motor. you pulled the exhaust manifold off? if you did and saw coolant coming from there, you have a problem. that's a headgasket. or a cracked water jacket. but i hope that's not what part of the motor your referring to.