Recently I had Infiniti replace my cooling fan motors and thermostat. The engine would overheat when in stop and go traffic and the ac was on. The overheating issue was fixed. However, after getting the work performed by Infiniti, I noticed that I started losing coolant. I didn't have an issue with losing coolant before getting serviced by Infiniti.

There are no puddles on the ground, and I can’t find any leaks coolant leaks. There is no coolant in the oil, and there is no moisture in the exhaust. The heater and A/C work perfectly and there are no issues with overheating. After a hard run, I open the hood and cannot see any steam escaping.

The coolant drops around (EDIT) 1/4 of an inch in the reservoir after about an hour of driving and after letting it cool for over 10 hours. It doesn't seem to leak when it hasn't been driven, but it is possible that it does in fact leak, but the drop in the reservoir is so small that it can barely be detected.

Two times in just over one week, I have had to add coolant fluid from just below the min mark to midway between the min and max. In the year I have owned the G before getting it serviced, I have never had to add any extra coolant.

I’m thinking it is just a tube that needs to be better secured to a connector, but I am not sure.

Any ideas?



07 Coupe AT.

 

When the engine is warm the level in the reservoir will always be lower

 

I meant the coolant dropped (EDIT) 1/4 of an inch from the level it was at before driving.

 

Maybe I'm misunderstanding but you're saying the level is lower after you drive, when the engine is hot, which causes the level to drop slightly. That's perfectly normal

 

I let the car sit for 10+ hours, and then mark on the reservoir where the coolant was. I then drive for about an hour. The next morning (after another 10+ hours of letting the car sit and cool), I check the coolant level and it is 1-2 centimeters below the mark I made the day before.

If i drive for another hour and let it sit for 10 hours again, the coolant will be (EDIT) 1/4 to 1/2 of an inch lower than the original mark.

 

Can you smell coolant after you drive your car? It has a very distinctive smell you can't miss once you know what it is. Take your G back to the dealership since they did the work, tell them what you're experiencing. They can do a pressure test that will show where your leak is....Gary

 

^^ +1 take it back the the stealership and have them do the service for it since they were the ones to work on it last.

 

Sounds like there is nothing wrong - just the cooling system stabilizing - usually no matter how well you bleed it, it will still have a bit of air trapped. Give it a week or two and the cooling system level should stabilize. When the engine is cool and on a flat surface, the overflow tank should be at "MAX" level. During normal engine operation the level will rise slightly above max. Keep checking before driving when the engine is cold and top off to max, that's how you can keep an eye on when the coolant level has stopped dropping. If the coolant level fails to stabilize after a week or two, then I would contact the dealership to check for combustion products in the coolant.

 

There is a scent of burnt coolant that can be smelled under the hood whenever the engine is run. However, that scent started when I was having engine cooling issues, and the scent I have now is considerably less pungent, and has been getting less powerful with each progressing day.

That is what one of my friends said, but I didn't really believe it. I would have expected that any air trapped in the system would have caused the engine temp to run higher than normal, or the heaters to not work, both of which are problems I am not currently suffering through.

 

^^^ What bythabay said. I had my cooling system flushing and filled with Nissan Blue coolant at Infiniti. I checked it before I left the dealer and it was full. After driving for a while it went down a few inches. After a week or two it stabilized and I topped it off.

 

I've driven it about 250 miles and the coolant level hasn't dropped. So it seems as though it is as both of you said. Thanks.

False alarm, I guess.