Coolant level fluctuating in overflow tank (1 Viewer)

[drowzyGX]

Check fluid levels every Saturday before running errands. 3 weeks ago noticed the level in the overflow tank was barely above the low marker. Been checking it daily since then. Always check cold, after the car has been off overnight.

The level is fluctuating between the low and the full mark. Never observed it doing this before. Radiator was replaced when I bought the truck, and the coolant level was always dead-on the full mark when I’d check cold. Temp never gets above the halfway mark (technically just a hair under it). No signs of any leak.

Shop that did the replacement offers a warranty. Had them take a look last week, and they blamed the radiator cap. Replaced the cap with oem, and it’s still fluctuating.

Is this fluctuation normal? Anything to be concerned about?

 

[Rednexus]

Mine's been doing the same thing lately. It seems to be dependent on if the engine is warm or cold, and if I'm on a slight incline or not. I've chalked it up to the frequent weather fluctuations we've had around here (0 to 75F), but otherwise have not worried about it.

 

[drowzyGX]

That is good to know. I did some googling and apparently this isn’t totally uncommon in other cars. I’ll keep an eye on it. I figure no leaks and no temperature jumps while driving…should be good to go.