Head gasket ?

[michelfloride]

Hi,

I was in trouble with a cracked thermostat housing, low coolant, engine overheated ......

Housing is replaced and by the way new thermostat

No noticeable leak
No water in oil
no oil in water
no smoke at tail pipe
No smoke at all
oil is clean and doesn't smell burn
no "sweet" smell
engine runs fine at idlle and high RPM
No over heating
to early to say if there is loss of coolant

No interior heating, but I know there is a broken vaccum hose somewhere( AC and heating vaccum ) so I assume it's normal

But I have bubbles in expansion tank !!! when engine is hot

also coolant in expansion tank stay cold even with hot engine....I don't know if this is normal or not

I suspect a possible blown head gasket.
If yes , what the risk to continue to drive the car, if I keep the coolant level OK?
I have to drive 200 miles this week end

Thanks

 

[sr139fox]

Blue smoke in exaust. Oil. White smoke in exaust, If you have access to a digital temperature gun check the exaust at the outlet. Compare all exaust. One that is significantly cooler could be a bad head gasket or other problem.

 

[JuBean]

ho long ago was all of the cooling system work done? Bubbles in the expansion tank sounds like the est of the system is just purging air and that is the only place for it to push that air.
The coolant in the expanion tank will not always be warm with the engine at operating temperature especially if the cooling system is low since it will expand in the radiator instead of pushing out to the tank.

 

[michelfloride]

head gasket?

Thanks

The repair has been done very recently. Before I posted my thread, I just drived the car 10 mn to check everything, but I was not confortable since I saw the bubbles
Afterward I drived for another 20mn, and you are right, the coolant becames hot in the expansion tank.
Still no changes, no white or blue smoke, no coolant loss, no odor, oil clean and odorless, temperature normal.....but still some bubbles in the expansion tank on a regular manner when engine hot.
I would say a few (5, 6) little bubles, half inch buble.....(how to explain "little buble"?) every 5 to 10 second, steadly.

I will try the temperature on the exhaust pipe, if one exhaust cooler could also mean a loose outlet or a bad exhaust gasket.......right?

Thanks

 

[koda2000]

If the bubbles in the expansion tank continue, you probably have a head gasket that is leaking compression into the cooling system. If the leak is small it probably wont make much difference to the way the engine runs. You could do a compression test and see what your compression is across cylinders. If you're not getting oil in to coolant, not getting coolant in the oil and the engine runs okay, just keep an eye on it. Certainly not worth tearing the engine apart right now.

The antifreeze in the expansion tank usually doesn't get hot. Warm maybe. What does your temp gauge read? It should be in about the middle of the gauge.

 

[michelfloride]

Update:
Following sr139fox advice.
I took the temperature on each exhaust.
240 to 270 variable on five cylinders, 180, steadily on cylinder 1.

No more bubbles after changing radiator cap, but I didn't drive the car I let the engine run half hour on idle on the drive way.

 

[michelfloride]

to Koda2000

Thanks for your opinion,

I am pretty sure I have a gasket problem, I don't know why, maybe just because I am unlucky with this fu......car!!
I confirm no water in oil, no oil in water, no smoke, no odor, and no noticeable loss of coolant.
Engine runs fine.
Temperature gauge stays under half by driving, a little bit higher on idle but allways under half.

Some bubbles and cylinder 1 exhaust cooler.......

If small leak, what if I continue to drive this car and keep an eye on the temperature gauge?
can the leak becomes worser?

What do you think about K&W gaskeat sealant?

Many thanks

 

[koda2000]

If you're pushing exhaust gases into the cooling system, no type of gasket sealant added to the cooling system will seal a leak in the head gasket. If you were pushing coolant into a cylinder (white smoke out the exhaust) a sealant might work as a last resort. If you're pushing oil into the cooling system, or coolant into the oil, you have a cracked head.

If the bubbles have stopped, then maybe sr139fox's advice was correct. If the bubbles continue, keep and eye on the coolant level. If it remains the same I wouldn't worry about it right now. If it continuously drops - worry.

You'll know if you have a serious problem when your engine starts to run like crap. I assume you have the 4.0L SOHC engine in your Sport Trac (don't believe the OHV was even available). Simply replacing a head gasket is usually not the solution (as heads tend to warp when overheated) and changing heads on a SOHC is not an easy or inexpensive job.

I'd keep my fingers crossed that it doesn't get any worse and I'd keep driving it.

 

[michelfloride]

This was my thought as Advance Auto Parts advised me to put some sealant in the coolant, it can work when coolant comes somewhere out, but not when compressed gases push into the cooling system, gases will just push the particles away.
What do you think about the exhaust temperatures?

Yes 4.0SOHC........a piece of crap, to replace the heads you need to pull out the engine, 3 chain belts , one in the rear, a nightmare......it would ne better to find an used engine........but difficult to find one

At this time it runs fine, I cross the fingers and will see over the next 500 miles.

Thanks you very much

 

[koda2000]

This was my thought as Advance Auto Parts advised me to put some sealant in the coolant, it can work when coolant comes somewhere out, but not when compressed gases push into the cooling system, gases will just push the particles away.
What do you think about the exhaust temperatures?

Yes 4.0SOHC........a piece of crap, to replace the heads you need to pull out the engine, 3 chain belts , one in the rear, a nightmare......it would ne better to find an used engine........but difficult to find one

At this time it runs fine, I cross the fingers and will see over the next 500 miles.

Thanks you very much

I'm not sure what to make of the difference in exhaust temps as measured. I don't feel the method used is particularly scientific. Good luck and report back.

 

[sr139fox]

#1 cylinder is running 100 degrees cooler. Could be from water being sucked in the chamber, or bad compression, pushing past the head gasket, or just a bad plug, wire, or other cause. I would pull the plug and compare it to another plug. Do a compression test when it is removed. That should tell you a lot about that #1 Cylinder. Swap plugs and check again. I agree, sealant won't fix a bad head gasket.

It could be trapped air in the coolant system. Elevate the front of the car, like on ramps. You want the cap at the highest point. With a cold engine, remove the cap and start the car, let it warm up, looking for bubbles. Sometimes the air will work itself out to the highest point. The removed cap should vent out the trapped air. Done this for years and works most every time. I only top off coolant when the engine is running with a warm engine. There is a vacuum tool used to apply to the cooling system to get the air out. Most garages have them.

If all else fails, drive the piss out of it and save for a new motor. It might last a day, week, months, or years. You never know. Good luck Dave p.

 

[Demo1986]

Do you really have to pull the engine to replace a head gasket? I have to replace a gasket because I have an external leak.

 

[boominXplorer]

These head gaskets usually do not leak, it's when the head heats up and warps they leak. They are MLS gaskets so they can't just "blow out" without rusting up first.

To the OP, If you want to make sure you got all the bubbles out get one of the funnels that attach to the radiator cap area and fill it half way up the funnel. Then squeeze all your hoses and see if you get any bubbles. Then let it run with it on there and manually activate the heater control valve so it flows. You can tie the arm back with 2 zip ties.

 

[michelfloride]

Do you really have to pull the engine to replace a head gasket? I have to replace a gasket because I have an external leak.

Yep, mine is a 2003 with a 4.0 SHOC.........I asked 4 mechanics, each of them confirmed the engine have to be pull out, one of them refuse to do it (he said the worst ford engine, a pain) an other one told me it is better to find an used engine.
There is a way to replace left head without pulling out the engine, but very, very difficult.

 

[michelfloride]

UPDATE
I drive the car since a few days
Still bubbles, engine runs fine.
I have a loss of coolant ( in radiator) of aprox 8 oz after 2 hours driving, but I suspect the coolant going into the expansion tank, so not sure about loss
When engine hot and on a stop or crossing light ,I can feel a little shake, from the engine, like a slight swing or like a low idle, only when gear is engaged.

WEIRD !!!
If I drive with open rad cap, coolant level stays stable and perfect, and no shake/swing on stop, everything looks to be normal even after 100 miles driving, it looks like I could drive from Florida to California without problem (???)........but I guess it is not normal, since a rad cap should be tight...........

Subsidiary question:
The coolant system is not like on my other cars, there is no relief cap on the expansion tank, just a plastic cap with a little hole and no seal......if I considere the configuration I even can't understand how coolant can come back from tank to the radiator, (1 hose from plastic tank to radiator cap, and coupling to radiator is above the cap seal)...... it looks like the tank is only for overfilled coolant in the radiator. Before overheating I never cheked the radiator, but only the tank, there was allways coolant in and also when the engine overheated, althought there was no any more coolant in the radiator.
So the question is HOW TO CHECKE THE COOLANT LEVEL?

 

[sr139fox]

Have you tried a new cap?

 

[michelfloride]

Oh yes cap is new...........almost everything is new on this ####ing car, it drives me nuts

 

[koda2000]

The cooling system is sealed. The overflow tank's hose is located in the bottom of the tank. When you heat water it expands and if the pressure in the radiator exceeds 16 lbs, it flows from the rad to the tank. When the radiator cools, the coolant gets sucked from the tank back into the radiator to keep it filled.

My cold coolant level in the expansion tank is about 3/4" lower than when the engine is hot.

If you find you need to add 8 oz's of coolant after 2 hours of driving and that your engine runs rough unless you leave the rad cap loose - that's a bad sign. Blown head gasket and probably a warped head. That's probably why you found one cylinder that is running 100 degrees cooler than the others.

Sorry for the bad news.

 

[michelfloride]

Yes, I came to the conclusion of a bad head gasket.
Anyway I continue to use the car and keep an eye on the temperature, can it going worse?

OK for the coolant back to radiator when temperature cool down. I think at the begining, associated to my leaking therm. housing and a bad thermostat sensor, my rad cap was bad....... instead to suck coolant from the tank it sucked air from the cap when cooling down, thats the reason I allways got coolant in the tank and no anymore coolant in the circuit.

sometime **** happen

Thanks a lot