ok 95 ranger 3.0 4x4 automatic trans, just rebuilt the top end about 6 months ago, with a brand new head on drivers side. lil truck ran fine but a little ruff at idle after rebuild, nothing to set codes! i put ALOT of miles on my lil truck as in a 1000 miles or more in a week.
the issue is that it is starting to run hotter than normal. normal = 175-185 deg, i have a 185 deg thermostat in it with a after market temp gauge so i can tell when the t stat opens! the temp is starting to creep up as in 195-200 deg and now im loosing coolant!
pulled the t stat just to be able to drive it, no noticeable or smellable coolant leaks.

would a clogged radiator cause this? i pray its not a head gasket that went!

sorry this is so long and thanks for all the help!
Mike

 

Clogged rad could cause this, the rad should feel hot all over with a fully warmed up engine, any cold spots on the rad indicate that it's blocked.

So what's the temp with the thermostat out ?

Did you test it on the stove with a new one for comparison _ they should open about the same rate ?

You say you're losing coolant, this makes no sense to me, any coolant that flows past the rad cap goes into the overflow reservoir on the fender well.
The reservoir shouldn't be so full that it over flows when the engine gets hot.

Head gaskets don't fail unless the engine is over heated. The heads expand, crushing the head gasket. When this happens the crushed head gasket doesn't seal anymore and you get leaks.
Plus you say you're not losing any coolant, so I'm going to assume the head gaskets are not leaking.

 

lol ikr jeff, when i open the pressure relief lever on the cap it will bubble in the over flow tank some times. somehow im getting air into the system, not sure how. when i checked the over flow tank yesterday it was half full, when i checked this morning it was almost empty. filled it back up to half full and then drove it, im waiting for it to cool down. and it ran warmer than it should with out the thermostat! it will normally run 159-160 with out the t stat. today it was 180-190 till i turned on the heat for a sec. that just tells me it is either eating coolant or blowing it out the overflow tank. but no fluid on the ground

 

and i wont let it over heat! 195 and i start to get nervous. i was thinking when they heat soak when ya shut them off. that might cause a gasket failure.

 

If it's using that much coolant, then it has to be going somewhere.
From what I've been reading here, it's running hot because you're loosing coolant, not because of a bad thermostat.

If you turn the heater up full, does it come out hot (engine fully warmed up) and then cool air ?

If I remember right, you used that copper spray gasket stuff on the head gaskets ???

You're getting air in the system because you're losing coolant.

It could be that's it's being burned in the combustion chamber, not enough to see huge plumes of steam out of the exhaust though.

Check your plugs and oil. You know what to look for.
Steamed cleaned plugs and milky oil.

EDIT, looked through your posts, you did use that copper spray gasket stuff _ at this point I would say that it's failing.

 

i have a oil leak so the oil gets checked every fuel stop, and it likes to sit about a half quart low and no chocolate milk thank goodness! im tired of puttin plug wires on it,cause one always seems to break when i pull them. but when the race is over ill go out and pull plugs to inspect and while im at it i might as well do a compression check to while im at it

 

Get your self one of these.

 

lol thats cool , i just got the pliers type, and yes i did use the copper spray gasket with new gaskets, the stuff i have was gave to me by a drag racing buddy of mine and he uses it on every engine he rebuilds, race or stock rebuild!

 

so far plugs 1 and 2 look great for the 2500 miles they have on them! i need a bucket or milk create to stand on for #3

 

if i cant figure it out before next weekend ill have to run it like i stole it for 3 hours to home and fix it there!

 

Take a pile of water with you !

When you used that copper stuff it was to solve a "popping" problem.
It was never discovered what was causing the popping problem.
From that other thread, I know it was solved after you used that stuff.
That's why I have my suspicions that something has gone wrong in that department.

If the mating surfaces are "true" you shouldn't need to use that stuff.
You also used it on the lower intake manifold, but it should be wet there if it was leaking.

We'll see what the rest if the plugs look like.

Nothing makes sense, that amount of water being used, one would think that it would show up as steam in the exhaust or make the oil milky.

 

well a update jeff, after i got something to stand on, all plugs look good (maybe to good for having 2000 miles on them), and depending on when im driving it ,(mornings here have been in the low 50's and in the afternoons its around mid 90's) mornings around 150ish and the afternoon with a\c maxed 185ish depending on my new 2 month old heavy duty fan clutch(sounds like a jet engine when it kicks in).
im heading home Thursday night to replace the radiator, and debating if i want to mess with pulling the old head and replacing it along with new gaskets! i think ill do baby steps, first radiator then test with heater core bypassed for now! i did notice this after noon that the water was bubbly in the radiator (little bubbles like dish soap bubbles) when i get home tomorrow i wont shut it off and i open the pressure relief lever to see if it gurgles the over flow tank. i check it every morning to make sure the overflow isnt empty

 

You should do Ron's glove test before spending money on a new Rad _ or anything for that matter.

 

https://www.ranger-forums.com/2-9l-3...4/#post2120151

He explains it very well here.

 

i already have a new radiator at the house. have been suspecting a bad rad for awhile now, last time i flushed it{ engine rebuild) hardly any coolant came out the petcock, had to pull lower hose to drain,

 

Coolant doesn't flow out that tiny petcock unless you let air in.
Did you have the rad cap off when you tried to drain it ?

 

Open rad cap when engine is cold, make sure coolant is at the very top, top it up if not
Put cap back on

Drive it normally
next time it is cold open rad cap again, if coolant is not at the very top then you do have a leak in the system

Overflow recovery system is very simple and works well
Radiator is full to the top cold
Rad cap has TWO valves inside
1. Pressure valve rated at 14-16psi, cap rating, has the large spring
2. 0psi recovery valve, small valve in center of the cap, small spring

When you heat up any fluid it will expand, same with coolant
As the engine warms up the coolant it expands, and this creates the pressure in the engine/radiator.
When pressure gets to 16psi(rad cap rating) its valve is pushed open and warm coolant flows out to Overflow tank, until pressure is below 16psi.
There are lines on the overflow tank, COLD and HOT, so it is normal for coolant to be sent out to overflow tank when engine is warmed up.

After the engine is shut off the coolant cools down and shrinks, eventually the pressure in the engine/rad will get down to 0psi
If any coolant was sent over to the overflow tank when engine was warm then the pressure will drop below 0psi, i.e. -1psi, thats when the #2. rad cap valve is pulled open and sucks coolant from the overflow tank back to the radiator to keep it FULL to the top
So after each cool down rad should be full to the top, if not then there is a problem

This cool down is when AIR can be sucked in from a leak
Air is much easier to move than coolant
A small leak might only leak a little coolant but it can pull in alot of air as engine cools down.

Overflow hose can also have a leak, so air is sucked back in on cool down instead of coolant.

If rad cap #2. valve is bad you will notice collapsed upper rad hose when engine cools down, negative pressure in cooling system.


Overflow tank hose is at the bottom of the tank for a reason, if there is air in the engine/rad system then it should collect at the top of the rad, at the rad cap.
When engine coolant heats up and pressure gets above 16psi then cap opens and any air is sent over to overflow tank first, it then bubbles up to top of tank and is gone
When engine cools down coolant is pulled back in replacing that air, so a self purging system if it is working correctly

This is why rad should be FULL to the top when cold, if it isn't then there is a problem

 

I had a leak in my over-flow hose, there was a sharp bit of metal that was chewing on the hose.
Mine was so small, I really wasn't losing any coolant and sucking very much air, but I could smell coolant, then one day I noticed this tiny plume of steam coming from the hose.

 

haaa think i smelled the problem today coming home from work (95 degrees in the shade)! i turned the a/c on and smelled a light musty coolant smell and as of right now i cant reach the pass floor board because of all the tools! so when i get home tomarrow ill clean it out and feel/look around! and for gp ill replace that hose as well! lol
the truck is 22 yrs old and i plan on keepin her that long or longer! thats why it dosnt faze me to throw parts at it! and thanks ron for the input, i understand why ya did it

 

ok another update! wow that was a hairy drive home! 3 hrs and the temp was all over the place! 160-195 and never constant! the truck is warming up as i type! replaced radiator, bypassed trans cooler in radiator for now with a after market cooler, if the tiny bubbles continue i will by pass the heater core! time will tell. i gota check my lil mistress temps, oh ya trans temp gauge is hooked up now so ill post that temp in a lil bit

 

blankedy blank blank blank....had the a/c on and it was sittin at 180 and when i shut off the a/c it dropped to 170! still running hotter than expected! the trans was at 140 so im ok with that. this is at idle for both with the thermostat removed. im waiting for it to cool off and then i will by pass the heater core and try again.

 

On my 1994 4.0l the heater core is always active, coolant always flowing thru it, no valve on the hoses.

It got old a clogged up a bit.
Temp gauge normally ran at just below 1/2 after full warm up.
It started to go up above 1/2 and then back down, randomly, no relation to uphill downhill AC on or AC off, would just start to go up above 1/2 and then back down to "normal".

By-passed heater core and was back to normal, put in new heater code and all was well.

Your 1995 may have heater core by-pass valve on heater hoses, if this valve is not working then you would get the same symptoms, or if HEAT is selected and core is clogged up then same symptoms.

So yes by-pass the system, connect the two hoses from intake and water pump together, by-passing the valve and core


Removing thermostat can cause temp to go up and down, put it back, and use 190-195degF model

180degF can't prevent overheating if there is a problem with cooling system, it just wastes your money with lower MPG and you run dirtier oil because of lower oil temp
The 15degF difference represents about 10seconds more warning of an over heating problem
Ford temp gauges have 210deg as 1/2 way, 220degF is not unusual just above 1/2, 250+ is over heating, about 3/4

 

wow ron i have never had a vehicle run at 200 or above! they have always been between 185 and 195. that is why i have the thermostat out right now. 180 with out t-stat for my lil truck is running hot, it should be around 150 and steady, not jumping all over like it is. 3 hr drive and i think i watched the gauge more than the road on this trip!

 

coolant system is down to just engine and radiator. found a very small crack in the vacuum line the the heater control valve ,thats fixed now. so i think im in to replace head gaskets and intake gaskets. i might pull upper intake to re torque heads and see what that dose

 

There is no indication at this time that you need to replace your head gasket(s).
Did you do Ron's glove test ? Go to the link in post 14.
Or even take it to a rad shop and have them pressure test it. Not expensive.
Same with you lower intake gaskets, if they were leaking you would see a puddle or some sort of seepage at the back of the engine.

EDIT:
Does you 99 have the "stretch" head bolts, is it even permissible or necessary to re-torque those bolts ?