So recently the weather has gotten cold and I have a coolant leak that only seem to happen when it's cold on the first drive. So after the car sits all night and cools down completely, when I go to drive it in the morning and whenever I stop after driving a few miles, I come out and see coolant leaking on the passenger side of the engine. When I drive it for the rest of the day, the leak seem to stop so I think it only leaks when the engine is cold.

When I open the engine bay, I can see that the rear of the alternator is wet. Both drive belts are wet too, although it seem like the power steering belt has more coolant on it. Although it seem like coolant is dripping down the passenger side of the engine even the oil pan and belt tensioner look wet. The wheel well plastic cover has coolant all over it when I checked today after the 1st drive this morning. I did see coolant dripping from the ac compressor down to the splash shield cover then down to the ground. I know our cars leaks from the water pump at this age, but I had mine done 2.5 years ago and 40K miles ago. Also if I'm correct a water pump leak would leak coolant straight to the ground and not get onto the drive belts and other parts on the side of the engine. It appears to not be leaking from the thermostat and coolant hose that secures onto the thermostat. Although it's hard to see into the thermostat as it's hidden under the timing cover.

What could be the cause of the coolant leak if it only leaks when cold on the first drive of the day? I can't see where it's leaking from exactly, but I'm thinking to go ahead and replace the thermostat and the thermostat gasket as that's the only thing I can think of that would leak onto the rear of the alternator and drive belt.

 

Clean everything and look closer. It could be a freeze plug in the head behind the timing cover. https://maxima.org/forums/5th-genera...lant-leak.html

 

So I looked at the link, I couldn't find where the freeze plug is, I did find another post where JVG mentioned the freeze plug is in the middle of the engine and the coolant would leak in the middle if the freeze plug is leaking.

I have a leak on the passenger side and it only happens when the car is cold and seem to spill coolant all over the wheel well.

 

In the first pic, it's the circle next to the thermostat and above the water pump. There are more of course.