2.5L ('98-'01) White smoke and cold hose

[MotorBoater]

so I uploaded a video to YouTube it’s only a minute long..

I have a 98 Ford Ranger with a 2.3 harness and pcm replacing the 2.5 harness and pcm. What could be causing a not so firm upper radiator hose that’s cold when the engine is warm all the smoke out the tailpipe? Now my first thought is head gasket with coolant leak and internally although the oil isn’t milky, but the exhaust smells sweet… I have replaced both O2 sensors, new cam sensor, new crank sensor, new thermostat because the other one got plugged up when I tried to use blue devil head gasket sealer, if you can leave me your thoughts, I would appreciate it because I’m about to push the truck off a bridge

 

[RonD]

Cold engine
Radiator cap off
Top up radiator with water
Start engine
Watch for radiator to start overflowing in the first minute or so, if that happens then blown head gasket or cracked head, for sure, its definitive

Coolant/water in the oil is not as common any more, it really depends where the head gasket fails, has to fail near an oil drain passage


Blown head gasket or cracked head allows air to be pumped into the cooling system on compression stroke(and firing), also sucks coolant in on intake stroke(which causes the white smoke)
The air displaces the coolant, so radiator overflows with cap off
The air also goes to the high points in cooling system and stays there, like upper rad hose and heater hoses, so they don't feel as hot even if engine is overheating

Its good there is no coolant/water in the oil pan, because oil/water mix will ruin the bearings if its circulated
So remove the head and have it pressure tested for cracks, and get a new head gasket

Pull out the spark plugs on the passenger side, the ones that are easy to get too, lol
Look at the tips
If a tip looks "Steam Cleaned" thats the cylinder that is leaking, there can be more than one

You also can find out which cylinder or cylinders have the leak using the Glove Test
Search on the forum for glove test


Original issue was most likely the engine was overheat because of a failure in the cooling system
Low coolant/leak
Failed thermostat
Failed water pump/fan belt

If allowed to overheat a head will get much hotter than the block
And any metal expands when heated, and expands even more when OVER heated, lol
So the head metal expanding CRUSHES the head gasket, causing the blown head gasket
OR
Head metal cracks from over expansion

So its not a chicken or egg thing, head gaskets don't just blow one day, and heads don't just crack
There was a previous overheating episode that started it all off

 

[scotts90ranger]

The engine might be warm but the whole cooling system likely isn't, I have 2/3 of my radiator plugged off and at highway speeds the engine doesn't warm up enough to get heat output under 50F, everything is new and in good order...

The Lima engines don't really blow head gaskets, they crack heads between the valves, could just put coolant into the exhaust with no other symptoms. I would observe for coolant loss over a few days.