Leaking coolant by the thermostat... then stopped

[Spark365]

Hi everyone, so I was leaking coolant from the thermostat for about 2-3 weeks, then, it completely stopped. No leaking at all. When it was leaking it was around 15-20 celcius outside, now it's always below 0. Can the temperature be a cause why it "fixed" itself and when it's going to be warmer it's going to come back? It's really weird

Thank you all

[Thunderguts]

If it was leaking at all, you know you have a problem that you'll need to address. A leak won't just "fix" itself. Are you sure it was coolant? If it was coolant, you're living on borrowed time. How many miles are on the car? It could just be a faulty hose/coupler. The thermostat and water pump don't normally leak, but you need to find the source and replace it.

My guess: maybe the engine isn't getting hot enough in sub-zero temperatures to build enough pressure to cause the leak. That's a bit strange because these engines like to run hot and will purposefully restrict cooling to build up engine heat.

[Spark365]

Originally Posted by Thunderguts

If it was leaking at all, you know you have a problem that you'll need to address. A leak won't just "fix" itself. Are you sure it was coolant? If it was coolant, you're living on borrowed time. How many miles are on the car? It could just be a faulty hose/coupler. The thermostat and water pump don't normally leak, but you need to find the source and replace it.

My guess: maybe the engine isn't getting hot enough in sub-zero temperatures to build enough pressure to cause the leak. That's a bit strange because these engines like to run hot and will purposefully restrict cooling to build up engine heat.

Yes I'm sure it was coolant, I had to fill up coolant in the expansion tank. The weird thing is that it would leak overnight when the car is parked for more than 8hours (approximately), but would not leak if it was parked for a small amount of time. Anyway, I did ordered the thermostat and water pump, I will replace everything if it starts leaking again

[NorthernDancer]

At the top front of the engine is a large coolant hose going into the engine. It's very easy to see. Between the hose and the engine is a plastic fitting and it's known to leak. I would suspect this fitting more than water pump/thermostat area.

https://www.ecstuning.com/b-ecs-part...024797ecs01~a/

Actually it's the same on N52, N54 and N55.

[dtla1]

Also check the tank itself for any signs of leaking, they tend to crack/leak where the two plastic piece of the tank, the lid and the box for the tank are fused.

[soursha]

Originally Posted by Spark365

Hi everyone, so I was leaking coolant from the thermostat for about 2-3 weeks, then, it completely stopped. No leaking at all. When it was leaking it was around 15-20 celcius outside, now it's always below 0. Can the temperature be a cause why it "fixed" itself and when it's going to be warmer it's going to come back? It's really weird

Thank you all

I have a similar issue and can't seem to figure it out. I already replaced the WP/Thermostat as well as the "mickey mouse" flange with an aluminum one. The reservoir seems to be dry too