The Stovebolt Site Forums The Shop Area Engine Shop 235 Won't stop boiling over

Hello Guy's , here are the facts .The truck is 1954 1300 Canadian, the engine is a 235 . Doing a repair for a friend .the truck boiled over big time last time he drove it.. I replaced the thermostat and things were good for half a day then boil over again this time with the rad cap from my own rad witch is working fine on my truck . Flushed the block for quite a bit then I replaced the water pump with a new one, ran good no boiling. Did a highway run for about five miles and pushed it had no problem, then next day boiled over again after a run to the parts store down the street , Replaced the rad with another known to be good one and another Thermostat also did a flush this time with a AC Delco flush additive,, boiled again after being up to running temp for about ten minutes . Finally removed thermostat all together same thing boiled just took a little longer, I figure there must be a blockage in the water jacket somewhere ....Out of ideas Please help
. Thanks Layback the prisoned with it lol.

Check the timing.

Air trapped in the cooling system. The water pump doesn't pump air.

If this Jeopardy what caused my engine to boil with no t stat.............What is the head gasket ? ( blown)

Is there the slightest amount of water/antifreeze in the oil ?

Second guess.........water jacket blocked.

Try pressure testing the cooling system- - - - -7-8 PSI is plenty, since that's what the truck was designed for. Leave the system pressurized for a few hours, then come back and see if the pressure is still there. If not, keep pumping it up and waiting. After a few tries, pull the spark plugs and spin the engine over with the starter. If coolant squirts out of one plug hole, you've found your leak. A slight compression/combustion gas leak will cause the symptoms you're describing.
Jerry

Thought about timing but engine starts every try and runs perfectly and pulls well,

Would timing explain that it was boiling i stopped let cool down topped up the rad and then it ran almost back down to normal for a mile till i got home.
(Don't know a lot about the timing).

I have made every effort to clear any air in the system , i ran the engine at idle with Rad cap off and let it bleed out ,Is there another way?

There is no sign of antifreeze in the oil no steam from the exhaust....... Talk about Jeopardy I'm inclined to go with the final answer water jacket blocked, What's the fix for that

Thanks Guy's Open to all ideas here

Will drain and flush the block again and do the pressure test .

Head gasket

Take the thermostat out, the fan belt off, fill with coolant to the top of the lower thermostat housing and start it up if you see any bubbles in the thermostat housing you have a compression leak. Usually a head gasket, warped head or a cracked head.

An easier way to check may be, depending on where your located and emissions machines at inspection garages availability? Is to simply check for hydrocarbons in the coolant system. Its the tell tale sign of, as stated b4, head gasket, cracked head, etc. And this way of diagnosing is performed without any disassemble.

there is a liquid check that involves drawing up air from the radiator and bubbling it through the checking fluid with a suction bulb. If the liquid turns from blue to yellow, you've got a small combustion gas leak into the coolant. If it turns green, you've got a big leak. Check the NAPA store for a "block test kit". I use one frequently during my warranty claim inspection business. O'Reilly auto parts has the same kit for less cost, but their test fluid sucks like a Dyson vacuum cleaner!
Jerry

Just a quick question, are you topping off the radiator or leaving about an 1 1/2 below the filler opening? They will burp out some coolant if there isn't room for the coolant to expand.
'

Yes have been leaving the air space, back shortly with full report

I hate to be the bearer of potentially bad news but I would say you have a blown head gasket or a cracked head. It's putting hot exhaust gas into the coolant. Pull all of the plugs out and pressurize each cylinder one by one with a compressor. You will need the hose to thread into the plug hole. These can be borrowed from auto zone as part of the compression tester kits. As you compress each cylinder the piston should push to bottom dead center. Listen for air hissing into another cylinder and pull the radiator cap off and look for air bubbling up through the radiator. If you find either you have a leak or a cracked head.

Did the Goose neck and fan belt off thing with no thermostat and the water began to bubble at about 189 degrees , bubbled once every 4 or 5 seconds. Did this a second time and it bubbled at around 175 degrees.

A mechanic friend of mien said to check the sparkplugs for whiteness at the tips, that it would indicate a leaking head gasket. Number one to number four have it, number one showing the most.

I also did the 7lb pressure test cranking the engine with the plugs out, I had cardboard in front of the plug holes while cranking but did not get any sign of moisture on it.

Right now there is only water in the engine I'm thinking it would have evaporated on the pistons by the time i got to the cranking over part.


I have tried to attach some pics but haven't used the photobucket in ten years not sure what will happen there.

Thanks for all the tips guess the next thing is to pull the head.

https://app.photobucket.com/upload

Photobucket is not the preferred way to post photos. Read the instructions in the left margin of every page. Very easy to do and posts directly to your thread. Lots of our members cannot see photobucket.

Well all this conversation and time spent speculating. You could of pulled the head and take a real look at what going on in there. Its already suspect that there is a head gasket or crack issue. Now have at it..

Just take Jerry's advise and buy a combustion gas in coolant tester (at NAPA or Amazon). I used one recently while chasing a problem on a diesel tractor. Easy Peasy and quick, only takes a couple minutes. Then you know for sure if the heads gotta be pulled.

RonR

Having the head pulled in a few weeks as soon as the shop we want can take it ,

Thanks again to all. Will up date then

Oh Wow folks. I cracked a 216 head while the temp gauge read cool. The water jacket was plugged and dry right under the gauge sending unit was the dry spot. Take the head off, it's easy and the valves probably could use adjustment anyway. Doc.

Hello again back at it after another Medical leave of absence. , finally got the engine apart luckily it was just the head gasket. While he/we where at it did the valves and gaskets. Running great now. Thanks so much to all for the help and patience .It was a great learning experience hopefully it will help others.
Be safe out there.