I've noticed that maybe every 6 months , somehow air gets into my coolant system . I can tell this because when driving slowly for an extended amount of time , the aux fan will come on when I stop . Ok . So then I park the Rover , wait till morning , and bleed of a small amount of air . Then I fill up about a tablespoon full of coolant . No more fan . So , I see many posts about waterfalls and fans . Very important to remove those stubborn airbubbles . Going on 5 years on my Turner engine . No problems . Just sayin'

 

If the weather is warm, the fan coming on after stopping could be normal, no?

 

Sometimes components on the top end have tiny leaks, they can suck in air, but due to their location, don't really drip. Sometimes any coolant that could leak dries up immediately so you never see a leak but later on see a build up of crusties. Top seam corners of radiators and the ends of upper hoses are common tiny leakers. The hoses you'll see a little build up of crust at the end of the hose, either due to hose breaking down inside at end or the clamp either failing (spring style) or needing a tighten (worm style). Or sometimes it's a freaking rodent that nibbled a heater hose enough for a pinhole leak then decided to die in your engine bay 🤣🤣

 

If I spent the $ on a Turner, I would make darn sure I tracked down a leaking coolant system. Would be cheaper to replace all the hoses than risk damaging the block or getting stuck. If you did not have a new block, I would say not to worry about it.

 

Get cooling system dye and uv light you find the leak in a couple of days

 

The amount of coolant loss and air , is of no consequence , really . In the Oregon summers , my aux fan never comes on . I guess I'm lucky . Turner engine was only $12000 . Included heads polished and ported . As for comparison , a top end rebuild for Toyota Sequoia is $10000 . I got the better deal.