Hi all i need some ideas of where to go next.
Ranger 2008 3.0 Turbo Des had a head gasket replaced 6 mths ago and now having over heating issues after driving for about 10 mins. It usually starts to heat to at least 3/4 after high speed and after pulling over straight away the temp will drop to 1/2 within 1 min if i just idle or roll. I have also noticed after when cooled down a loss of coolant in Rad. Also the lower hose is always cold to touch when the upper hose is hot. Heat blowing into cabin when turn on fan to hot OK.
so far I have changed the upper hose as it had an extremely slow leak, still over heats.
had the thermostat replaced, still over heated.
bravely removed the thermostat myself (with help from a man to tighten bolts) and tested in boiled water and it functioned OK, so put back in.
At same time drained the whole system, took out the water pump, the pump seems to turn OK without noise and the fins looked good, so put it back in.
Cannot find any external leaks anywhere.
so put in a another second hand radiator as a test, still over heats. Ran a hose through it prior and seemed OK?
filled up the whole system again and burped the air out for about 15 mins because at first it appeared to have a large bubble coming up every 10 secs when running without cap on.
Planned on doing a flush tomorrow but wonder if another head problem again? no water in oil, no oil in water, runs well, but the bottom hose cold has bugged me? the bubbles appeared to have stopped. could the pump still be bad even if it looks and sounds OK? Any ideas would be appreciated, thanks

 

If upper hose gets hot and lower hoses stays cool then radiator is plugged up, flushing might help but you will most likely need a new radiator

There should only be a 20degF difference between upper and lower rad hoses, i.e. if upper hose is 190degF then lower should be 170degF, so both in the "hot to touch" range

It can also mean the water pump is not circulating coolant fast enough, so a judgement call

EDIT: re-read you post

Are you sure fan belt is on the correct way?
On many vehicles you can route fan belt incorrectly which turns the water pump in the opposite direction, so limits circulation
Had to ask

You can do the Glove test to see if head gasket is leaking again
Cold engine, take off rad cap
Put a latex glove over rad cap opening so its sealed, plug overflow hose port if it has one
Crank or start engine
If glove starts to inflate you have a cylinder leaking pressure into the cooling system, so bad head gasket or cracked head

 

Thanks for your reply, appreciate it.
Today I gave the system another bleed but this time I drove the car up on one ramp (the rad. Opening side) and turned on the heat fan inside the car to full. (Something I totally forgot about doing before). After about a couple of mins of operating Temp, all the bubbles stopped. I continued to do this for another 10-15min still no bubbles then topped up coolant and took for a drive around all the back streets for about an hour and NO overheating issues (before it would overheat in the first 10 mins). The only issue I have now is the orange engine light turned on during the last 5 mins of the drive, so I came straight home. The overfill bottle had only raised by about an inch, the bottom hose still cool to touch, however, the metal pipe that attached to the thermostat coming off my bottom hose was warm to touch (Before that remained stoned cold). The engine didn't appear to be overheated either. I haven't flushed yet, but now I'm a bit worried about this engine light coming on. My mechanic is booked out till late next week so trying to figure the issue out myself in the meantime. To complicate the matter, I can hear water gushing around the front passenger side, like its behind the dash under glove box area....?? its been raining so maybe just a water leak, or maybe a clogged heater core thingie we bob? If I get a mechanic to do a scan would a code come up to explain the engine light issue?

 

Yes, the engine light means there is at least 1 code in computer's memory

You can buy a Bluetooth OBD2 reader for under $25, it works on any OBD2 vehicle since 1996, it uses your smartphone at the display, the APP is free or $5 if you need more detailed code retrieval, which most don't
The reader plugs into the OBD2 port in the cab and then you connect to it via Bluetooth, wirelessly, on a phone or tablet, very simple to operate and as said works on any vehicle, not a Ford thing