![Froth/scum under radiator cap. I've replaced the cap twice, flushed the coolant twice, and am not burning/losing coolant. No coolant and oil mixing under oil cap/dipstick. Clean the cap and it keeps Froth/scum under radiator cap. I've replaced the cap twice, flushed the coolant twice, and am not burning/losing coolant. No coolant and oil mixing under oil cap/dipstick. Clean the cap and it keeps](https://preview.redd.it/1tuf7y7cbqv51.jpg?auto=webp&s=368b4f0916c841d1f97967d35b65c5171536c33e)
Froth/scum under radiator cap. I've replaced the cap twice, flushed the coolant twice, and am not burning/losing coolant. No coolant and oil mixing under oil cap/dipstick. Clean the cap and it keeps
![White sludge on radiator cap. 2010 pathfinder 4.0L V6. Was doing an oil change and inspection. Im a 1st year mechanic, been in the field for 1 year now. What causes this? White sludge on radiator cap. 2010 pathfinder 4.0L V6. Was doing an oil change and inspection. Im a 1st year mechanic, been in the field for 1 year now. What causes this?](https://i.redd.it/4x5ock9ntg431.jpg)
White sludge on radiator cap. 2010 pathfinder 4.0L V6. Was doing an oil change and inspection. Im a 1st year mechanic, been in the field for 1 year now. What causes this?
![Amazon.com: Comfort Zone CZ8008N 1,500-Watt Electric Oil-Filled Radiant Radiator Heater, Permanently Sealed, Never Refill, Adjustable Thermostat, Stay-Cool Handle, Tip-Over Switch & Overheat Protection System : Comfort Zone: Home & Kitchen Amazon.com: Comfort Zone CZ8008N 1,500-Watt Electric Oil-Filled Radiant Radiator Heater, Permanently Sealed, Never Refill, Adjustable Thermostat, Stay-Cool Handle, Tip-Over Switch & Overheat Protection System : Comfort Zone: Home & Kitchen](https://m.media-amazon.com/images/I/71iIkxyI7JL.jpg)