The Nissan Path

I've read a few posts about air getting trapped in the coolant system- which I think I have and will try to purge this weekend. I do have a couple questions on this though. I was having the cool air at idle issue and noticed my reservoir tank was low, so I added about a quart of coolant and this helped for about a month. I did the same thing a month ago and now its happening again. When I had my oil changed last week at the Nissan dealer, they said my tranny fluid looked ok. Is it normal to go through this much coolant in the winter? -I just moved up here from FL and have never used my heater this much. Also, is it bad and why would it be, to have the fluid in the reservoir tank above the max level line?

When the engine gets hot, the coolant expands until it reaches the pressure limit of the cap and pushes coolant into the reservoir. As it cools, it contracts and creates a vacuum that pulls the coolant from the reservoir back into the engine. So, if the reservoir is overfilled, the coolant could get pushed out the reservoir vent and leave a puddle of coolant on the ground (as well as the parts of your engine compartment that it runs down). If you have rear heat and a large air pocket in the system, you could see some loss in coolant as the air is slowly purging out of the system. Another possibility is there is a leak in the system. If you have rear heat, you may want to check the coolant lines that run along the frame to the rear heater core as they have been known to develope leaks on some Pathfinders. Of course, check for leaks under the hood and at the front and rear evaporator case drains. As far as "purging," make sure the system is full, turn all of the heaters to the maximum heat setting and jack up the front of the vehicle as much as practically possible to let any air in the rear heater lines/core (if equipped) to move towards the front of the vehicle.

Thanks. That makes sense. Also, I do not have much if any heat coming out of my rear ceiling vents. I couldn't find any leaks in the engine bay, but I will check for leaks along the frame as you suggest.

check your transmission fluid as well. Hope the radiator is not broken and leaking Coolant into your transmission.

The tranny fluid is ok. I did find a leak at a connection right by my rear passenger tire- behind it a little along the frame. It looks as if someone tried to fix it before and did a shotty job. There is a hose connected to a coolant line connected with hose clamps. I bought it used with 92k miles a year ago. I took it to a local shop this morning and they want to charge 550 bucks to fix it! Parts are cheap, but they want to charge $85 /hr to fix and drain the coolant/refill/get air out. Seems a little high, but ? I'm taking it back in tomorrow to get fixed.

I just found this thread which shows the same problem I have. Something to keep an eye on...

http://www.thenissanpath.com/viewtopic. ... sc&start=0