88 Ranger overheating BAD PLEASE HELP

[PowerRanger]

I bought an 88 ranger xlt 2.9 4x4 recently and it's had some issues overheating. I replaced the radiator, thermostat, hoses, and flushed the system, and added an aftermarket temp gage. This morning the truck ran fine, idled around 180-190 but tonight it's been sitting at 230 -245 while I drive. I don't really know what else to do and now I've got yellow snot coming out of my oil filler cap (cap on, it's leaking out somehow). Pretty sure that means i have a blown head gasket or cracked heads. But why is it leaking out like that? And why is it still overheating so bad? I have no idea what to do now and I could really use some kind of advice since this is my only ride to and from work. Thanks for any help in advance!

 

[lil_Blue_Ford]

Hate to say it, but it will overheat if the heads are cracked.

Is it losing coolant?

Is it blowing bubbles in the reservoir tank when it's running?

Does it make weird bubbly noises when you shut it down?

Have you pulled the dipstick? Did you suddenly get more oil showing on it?

Did you replace the radiator cap when you did everything else?

There is also a chance that the water pump has given up. Usually you'll see some coolant leakage from weep holes in the pump, but not always.


Sent from my kite using a trebuchet

 

[RonD]

Welcome to TRS

"Blown" head gasket, or cracked head, means that at least one of the cylinders is pumping "air" into the cooling system, and often sucking water/coolant in to the cylinder from the same leak.

Each time you crank the engine each cylinder has at least 150psi compression, if there is a leak then some of that pressure(air) goes into cooling system.
When engine is running pressure in a cylinder is 900+psi when it fires, so..........

This "air" displaces the coolant in the head(high spot where air goes) so less cooling and engine starts to run warm.
Overflow can start to fill up with displaced coolant, and start to bubbles as some of this "air" reaches radiator cap and is pushed out into overflow tank.

The "air" can also form "air dams" blocking coolant flow in some areas until it clears causing spikes in temp gauge.

Cold engine
Remove rad cap
Top up rad full, use water
Start engine
If water comes out of rad cap opening and continues to come out then you do have a cylinder leak

Search "Glove test" as this site, that can ID a leak for sure and even what cylinder(s) are leaking.


If an engine with a blown head gasket is run long enough coolant will get into the oil, check dipstick for over full and milk shake color, if that happens then bearings can be damaged because coolant turns to steam when it gets to hot bearing surfaces and that displaces, washes off, the oil on the bearing so bearing gets "cooked" with no lubrication, a bad thing