I have a 2002 4L with 265K. It ruptured (split) upper heater hose. Replaced, still overheated. replaced thermostat. Still overheating and has a high pitch whistle-like/tea kettle sound coming from engine area after it starts to warm up. Any thoughts?

 

I’m thinking perhaps your water pump impeller may be wasted, and not moving the coolant, especially considering the mileage of your vehicle. If the water pump is original, I would think that’s a lot of miles on that component, and impending failure wouldn’t be too far out of question. I would also consider giving the radiator a good flush out as well.

 

When you replaced all this stuff and re poured coolant into it, did you burp your cooling system? If not you could have air in the system and could cause overheating

 

whistle and high pitched noise, sound like you water pump

 

Thanks Bearstream. Water pump is good. I've been told could simply have air in the system. Apparently after doing work on the cooling system one should add the coolant directly into the radiator and not into the reservoir. Found out that was it.

 

That was it. Thanks. I was advised that when working on the cooling system, to refill directly into the radiator and not into reservoir as I did. Can cause air in the system as you suspected.

 

Nope. Pump good. Turns out it was air in system. Running fine now.