Foaming coolant under heavy load, bad head gasket?

[bavArian]

Hello guys,

took my A for a longer trip today. Around 105 mls at ~30 °C / 90 °F weather. With my cooling problems I had to stop several times and generally go slowly, but we made it. I did notice however that as soon as I hit the gas hard (with the engine properly hot) the radiator almost immediately foams up.
A second after I step off the gas the foaming lessens considerably or even stops entirely. If I for example drive in 2nd gear with higher rpms without much gas/load that does not happen.
It also does NOT happen when the engine is colder, a minute or two after startup for example.


So it has to do with the pressure inside the cylinder. After arriving at home and letting the engine cool down a bit I removed the water pump belt, topped off the rad. and let the engine spin up from idle as fast as it can. (full throttle)
I could see one or two rather small bubbles (0,5 to 0,75 in diameter?) surface in the rad. neck around a second after each spin-up. Nothing when running at high rpms without load. In my opinion that points to a faulty head gasket.
BUT there's two things that slightly confuse me:
a) There is absolutely no white smoke coming from the exhaust or carb.
b) I have no measurable coolant loss when the car is sitting.

I did check the head nuts with 45 ft. lbs. (without loosening them up first) just to see if one of them is loose. (engine was still warm, about 45°C / 110 °F so I didn't want to use the 55 ft. lbs.)
None of the nuts were loose.


Tomorrow when the engine is cold I'll probably loosen and torque up each head nut in the proper order just to make sure it's not only a lack of torque.


From the symptoms I've described I guess that's only a really small leak? I've seen videos of faulty head gaskets, there's usually a lot of bubbles in the rad. neck even at normal or fast idle.
Could it be a crack in block or head or do the symptoms I've described usually point to a bad head gasket?


Does it make sense to try a sealant for the coolant like Bar's Leaks first or do these generally not work even with small leaks? Seems like opinions on these products differ, but nevertheless I'd like to hear them.


Thanks and have a nice day,


Daniel

[TMarsh]

Are you sure you are having an overheating problem, and not just a foaming and loss of coolant issue. I had a similar problem with foaming and it turned out to be the combination of the antifreeze I was using and some preventative radiator sealant. Flushed everything out and replaced with 50/50 green Prestone. Problem solved. Do not fill above core tops. Check with meat thermometer or H/F infrared sensor. Maybe you will get lucky like I did and not have to go into the engine right away.

[bavArian]

At 110 °C / 230 °F coolant temperature, yes, I'm sure I also have problems with overheating.

I just don't know how much of these temp. problems may be head gasket related yet.



There def. is a certain problem with combustion gases in the water. It isn't as severe as a completely blown head gasket, but somewhere there is a small leak. I just want to know how best to tackle this problem.

[nkaminar]

Yes, re-torque the head to 55 ft-lb in the morning. As T Marsh said foaming can be caused by a combination of chemicals in the cooling system or just some weird antifreeze. Foaming will not cool the engine. Water and antifreeze conducts heat much better than bubbles. Drain, flush, and fill the cooling system with water. Do a test drive. If it stays within operating temperature, then drain out the water and add 50/50 water and a good brand of antifreeze. T Marsh had good luck with the green Prestone.

[katy]

Originally Posted by bavArian

Tomorrow when the engine is cold I'll probably loosen and torque up each head nut in the proper order just to make sure it's not only a lack of torque.

Good plan, you only need to back the nuts off 45 or 90°.

[nkaminar]

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In case it is not obvious, back off only one nut at a time.

[bavArian]

Thanks, but the one-at-a-time is obvious.


Forgot to mention that I did flush the rad. with water already. I'll try once again with vinegar mix after retorquing.

[BTERRY29]

Do a leak down test. Simple to do and you can rule out head gasket. Could just be cavitation from the water pump.

[bavArian]

Originally Posted by BTERRY29

Do a leak down test. Simple to do and you can rule out head gasket. Could just be cavitation from the water pump.

I had the bubbles with the water pump drive disconnected.



An hour ago I marked the head nuts and studs, and one at a time backed each of them off and torqued them again. I did follow the order in Les' red book.
Except for studs #s 9, 11 and 13 all arrived exactly where they were before. #9 could be torqued about 40° (very rough estimate) further, #11 and 13 only a little bit further than before.
I'll do a test drive in a few days when I have some spare time and check if the problem was solved or if the head has to come off.

[w.michael]

I had a very small crack in a head that would not leak until the engine warmed up and the crack expanded. I think that sounds like what is happening with your engine. The solution was to replace the head. One of our great engine rebuilders who posts here “gave” me a stock head, charging me only a very reasonable price for bead blasting, magnafluxing, and decking the head.

W. Michael

[1crosscut]

Test the coolant for combustion gases. There are simple test kits available here at auto parts stores that are pretty inexpensive. I would think that they would be available there.
It is a liquid that with the engine running you pull the air off of the top of the radiator through the liquid turning it a different color if gasses are present.
It will almost surely answer the question as to if you have exhaust gas leaking into the cooling system.

[bavArian]

Update:


Took the A for a short test drive in nice and chilly 28 °C / 82 °F weather *sweat* and tried to provoke the "overfoaming" by accelerating pedal-to-metal/wood at medium to high revs in 3rd gear.

It still gets too hot (which I anticipated) but the coolant doesn't foam at all anymore. So it seems like it really were the 3 head studs putting not enough pressure on the head gasket to keep a seal under heavy load.

Nevertheless I'll keep an eye on that.

[katy]

Thanks for the update.

[ronn]

vinegar mix should stay in the cooling system for a few weeks. It doesnt do much if immediately removed.

[jack backer]

Change head gasket

While head is off, check/ clean water jacket.

Find an industrial hot water pressure washer with chemical degreaser ( most tractor repair/ truck shops have one) use the hot water to get the radiator hot (200 degrees plus) and flow the water/ degreaser back and forth through the radiator, getting it hot expands the tubes, the degreaser breaks down the grease/ dirt blockage.

Regardless of ambient temperature your car should operate consistently at 160 degrees..no “cool down” or reducing load required.

[wwirz]

It could be that you overfilled the cooling system. Mine also "frothed" when I overfilled it. As a starting point the coolant level should only be as high as the baffles. You likely do not have a problem at all except for too much coolant in the system. It stopped coming out of the bottom of the cap because the coolant found its own level. Drive it, have fun, keep an eye on it.

[bavArian]

Originally Posted by wwirz

It could be that you overfilled the cooling system. Mine also "frothed" when I overfilled it.

Nope, it's not a problem with overfilling the radiator.

a) I didn't have this problem for the first few weeks this year and
b) It stopped immediately after I retorqued the head.


Unfortunately I can't drive the car at the moment as we have temperatures of ~34 °C / 93 °F the last few days. That would be taxing even with a good cooling system, and mine's not good atm.

[jack backer]

Fix it correctly and high 90’s ambient temperature only affects the operator, I run 9% grades in 90 degree weather no problem. Once sorted out the ambient thermal threshold for proper heat exchange is quite high, ford ‘over engineered’ the cooling system.

[henryford30]

Hallo, ich heiße Josef und komme aus München.
Ich habe deinen Thread über das überhitzen gelesen. Mein 30er Ford hat genau das Problem wie du es geschildert hast. Habe den Kühler durchgespült, der ist blitzblank!! Werde jetzt noch den Motor durchspülen, aber ich denke es kommt eben von der Kopfdichtung.

Vielleicht kannst du mir einen Tip geben, kannst mich gerne auch anrufen, da kann man doch besser über das Problem reden.
Vielleicht kannst du mir eine PN schreiben, dann könnte ich dir meine Handy Nr. geben.

Danke dir schon mal !!!


Viele Grüße


Josef

[katy]

Originally Posted by henryford30

Hallo, ich heiße Josef und komme aus München.
Ich habe deinen Thread über das überhitzen gelesen. Mein 30er Ford hat genau das Problem wie du es geschildert hast. Habe den Kühler durchgespült, der ist blitzblank!! Werde jetzt noch den Motor durchspülen, aber ich denke es kommt eben von der Kopfdichtung.

Vielleicht kannst du mir einen Tip geben, kannst mich gerne auch anrufen, da kann man doch besser über das Problem reden.
Vielleicht kannst du mir eine PN schreiben, dann könnte ich dir meine Handy Nr. geben.

Danke dir schon mal !!!

Viele Grüße

Josef

Translated:
Hello, my name is Josef and I come from Munich.
I read your thread about overheating. My '30 Ford has exactly the problem you described. I flushed the radiator and it's sparkling clean!! I'm going to flush the engine now, but I think it's coming from the head gasket.
Maybe you can give me a tip, you can also call me so we can talk about the problem better.
Maybe you can write me a PM and I could give you my cell phone number.
Thank you in advance!!!
Best regards Joseph,,,,,,,,,,,,,,,,