4.0 OHV Burning Coolant

[Big Jim M]

This could also be a bad rad cap.If your losing pressure your boiling the coolant.For every pound of pressure drop you lower the boiling point 10 degrees.Have the rad cap pressure tested or just get a new one with the correct pressure.Just a thought,most people over look this.

Jagar water boils at bout 212* If a 16lb cap adds 10* for every lb of pressure the coolant won't boil until 370* or so degrees is met.. For sure your information is incorrect. With a good cap the coolant boils at bout 260 degrees..don't it?
Big JIm

 

[JoeCanada]

I'm also having a similar problem...I was towing my dad's boat home from the lake a couple weeks ago, when I noticed my temp gauge was pegged hot after about 2 hours of driving. I pulled over ASAP, and found almost no coolant left in the system. It was so hot, in fact, that it was starting to melt the valve cover gaskets.

I let it cool down and filled it with water, and managed to limp home, but the temp gauge was still hovering around the high side of normal, and I kept having to top it off with water every 20 mins or so.

I took it for a quick drive the other day, after filling it with water again, and the temp gauge jumped right up to the top after only a few minutes of driving, and there was white smoke coming from the exhaust at idle. So I took it home, and haven't touched it since. I just replaced the lower intake gasket a month ago with a Ford OE replacement.

My question is similar to redranger's: How do I diagnose what my problem is? I assumed blown head gasket, and my plan was to take the heads to the machine shop and have them pressure tested, and put new Ford headgaskets on. But how can I be sure that it is the head gasket before I take everything apart?

 

[Big Jim M]

The first thing to do is to make certain what the problem really is.. Fill it and start it in the driveway and watch for outside leaks while it is idleing... Also with the cap off and a hose near with a small rickle of water coming from it start the engine and while keeping the thing full with the trickle watch for bubbles coming regularly from a blown head gasket..
Before taking the heads off be sure and certain what problem you have.
Big JIm

 

[94redranger]

so if it does bubble up than it is head/head gasket failure? Is there any way to tell if it is the intake gaskets besides physically checking them?

 

[Big Jim M]

so if it does bubble up than it is head/head gasket failure? Is there any way to tell if it is the intake gaskets besides physically checking them?

First thing I'd do is eleminate other possible leaks.. If it doesn't leak outside the coolant system and it doesn't have bubbles..then it is prolly the intake gasket...BUT one truley doesn't KNOW that until everything else is eleminated..
Big JIm

 

[Bob Ayers]

so if it does bubble up than it is head/head gasket failure? Is there any way to tell if it is the intake gaskets besides physically checking them?

With your engine idling, try spraying carb cleaner at the lower intake-head interfaces. If the lower intake gasket is leaking, you will see a change in RPMs when the carb cleaner hits the leak. Also, if you check the lower intake bolts, and they are loose, this would be a good indicator of a leaking lower intake gasket.......

 

[MAKG]

With your engine idling, try spraying carb cleaner at the lower intake-head interfaces. If the lower intake gasket is leaking, you will see a change in RPMs when the carb cleaner hits the leak.

While that should work, most of that interface is inside the valve covers.

 

[JoeCanada]

Can a leaking lower intake gasket cause 'white smoke'?

 

[Big Jim M]

Well...yes it can..but a small amount of oil can also make what can be considered white smoke.. You are guessing until you start really trying to find out what the problem really is.
Big JIm

 

[MAKG]

If you have an automatic transmission with a vacuum modulator, that can cause white smoke as well. Along with a vacuum leak.

 

[JoeCanada]

With the engine idling, and the rad topped off, the water bubbles out rather ferociously from the top, in addition to water dripping from the tailpipe. So I would assume this means the head gasket is the problem?

 

[Big Jim M]

Joe my guess, from reading your remarks, is that you have had a slow leak and ran out of coolant while pulling that trailer.. Then you overheated the engine and now have cracked a head or block, if you are lucky all you did was blow a head gasket.. I would advise taking the heads off and having then looked at by a professional. Take the head gaskets with them for him to see. Then do as he advises about repairing the engine.
Don't forget to install a new thermostat when you put it back together.
Big JIm

 

[MAKG]

And a new rad cap. And inspect the water pump, heater core, radiator, core plugs, and all the hoses for evidence of leakage (usually, corrosion on metal parts or white deposits).

Generally, certifying heads as good requires special equipment (Magnaflux) and some experience. But if you can SEE a crack, you know it's bad and might as well save your money.

 

[woodyedmiston]

Also check the bottom of the overflow tank for a linear crack. Mine lost water without putting any on the ground for weeks before I found it - in my 93 ranger. My 99 began to loose water, the coolant tank was fine. But - if found my daughter had been filling the coolant tank to the top regularly for a year - it diluted the anti-freeze and started the freeze plug (please don't anyone jump in and say it's some other kind of plug) above the starter and oil filter to leak gradually. By the time the drops ricocheted off of all that they never hit the ground. But the top of the oil filter housing was wet. The seeping plug looked like it had a tiny dirt dauber nest on it.

 

[94 splash]

and you can alwaus do a compression test ..do u can see what side is giving u a prob