The Stovebolt Site Forums The Shop Area Engine Shop Truck radiator boils over :(

Well, I guess maybe I jinxed myself yesterday in the discussion about jw51 and Bill hanlon's flush jobs on their trucks. Old Roy (1950 1/2-t) overheated today on the highway and is now sitting in a gas station.

The water was boiling out of the overflow reservoir. There are no evidence of ruptures or leaks anywhere else. I'm wondering if the thermostat could have stuck shut or if some crud somewhere in the system was dislodged and is stopping up the works.

My immediate concern, however is how to get the truck out of there. I intend to let it cool down and either fill it back up with water and drive it to 10 mi to my mom's house, or remove the thermostat and drive without the thermostat out to my mom's house 10 MI rather than go the 30 mi back to my own house at least until I figure out what's going on.

The Sam's club fuel center attendant was kind enough to loan me his car to come out here and get tools so I've got to get back there ASAP and get this show on the road.

Any suggestions are appreciated. And if anybody has any specific advice or wants to call me in person, feel free to do so. My number is 678-358-7890.

It's cool down sufficiently to touch all of the parts under the hood including the exhaust pipe and hoses. I decided before dismantling anything that I would pour some water in it and start it up and see what happened. The water is Rusty Brown so I suspect that something broke loose inside of there, a hitherto unknown piece of Rusty debris or whatever and move to a position to clog things.

When I filled it with cold water and started it up it does not appear that water is flowing

Well, I think what I'm going to do is just fill it back up with water and drive the 10 mi to my mom's house. When I'm there, I can then more comfortably remove the thermostat or hoses or whatever I need to to do some exploratory investigation. And if it overheats or gets too hot I'll just pull over on the side of the road and let it cool down I got a 5 gallon bucket of water with me

Otto, Glad to see you gave us an update. Maybe we should change the title of your thread again now that you have tried a few things. It seems Bolters respond better when the Title is clearer. Or may you may want to just start a new thread, with a post asking for input on what you find once you get Ol Roy to your Mom's??

When I was first driving my Model A to college (normally a 1-1/2 hour trip) it had a clogged radiator. I would run till it started steaming, pull over and refill the radiator. The trip took about 4 hours with the stops to fill the radiator. Once I got the radiator re-cored, things were fine.
Your 10 mile trip with some extra water should go fine.

Yes I just got out here to my mom's and was able to keep the temperature just under 212° on the gauge, which has proven to be very accurate when compared with a infrared thermometer. As long as I was moving it 40 to 45 with the heater on full blast the gauge stayed right around 210°. Only when I had to stop behind a slowpoke did it go over to 212°. With a 4 lb cap I figure it's going to boil over at 224°.

Now that I'm out here, I'm going to let it cool down and drain everything and flush it with clean water at first and see what I can come up with. I think also I'll remove the thermostat and take a look down there and see what kind of Gunk has been dislodged from the bowels of the engine

Probably a good plan. Glad you made it.

I recall having a stuck thermostat on a family station wagon when I was a kid. There were hammering sounds coming from the engine. The mechanic we pulled into just removed the thermostat and we drove on without problems. I would check the thermostat to see if it's stuck shut, or just replace it with a new one.

Just took the cap off and it was not boiling so the temperature stayed below 212 and I can stick my finger in it for a split second without being scalded. Nevertheless it obviously is brown and it's running hotter than it is supposed to

A quick emergency fix is to remove the top radiator hose at the thermostat housing and poke the center out of the thermostat with a big punch or a screwdriver. Top the system off with plain water and drive on to somewhere you can do more diagnosis and repair. There's nothing small enough to pass through the upper hose and get trapped in the radiator, so you can scavenge out all the bits and pieces that get dislodged pretty easily.
Jerry

I pulled the thermostat out and I'm going to test it in a pan of water but it although had a lot of powdery rust particles and crud on it nothing big that looked like it might have been stuck. It is surprisingly a 160° thermostat. I have always assumed, for no particular reason, that it had a 180° thermostat in it.

The 160tat seems to be working just fine on the kitchen stove

When the engine boiled over, what was the outside air temperature?

Outside temp was probably around 90 or so maybe in the 80s. However I've driven this truck in 95 plus degree weather in rush hour traffic and never had overheating issues.


I found a appropriate thermostat housing gasket in the barn and put a thin film of wheel bearing grease on each side and sealed the thermostat housing back up. It drove it around for a while and it stayed around 195 instead of 180 but crept up to close to 2:12 when I pulled in the driveway and was idling. I took up some slack in the fan belt in case that might be a contributing factor but probably not the ultimate problem

Agree, should run OK in 90 degree weather.

No doubt you've checked ignition timing, fresh and full oil in the crankcase, etc. Could the water pump all of a sudden have failed to circulate coolant efficiently; e.g., worn or broken impeller(s)?

I would suspect the water pump. Does the water seem to be circulating with the radiator cap off after thermostat opens at 160? You would need to let it cool enough to remove the cap and let it idle until the thermostat can open. It should be easy to tell when it opens. JMO

Yes, thats a good way to check if the water pump is working. That water will start flowing when the themo opens.
Rusty brown is a concern.

I also am suspecting the water pump.

I found a T stat housing gasket for a Ford 460 in my Mom's barn that fit so I put the housing back on with the 160 T stat left out.

I drove around 6 or 8 miles and the temp stayed around 196 for most of the driving but climbed to around 210+ when I pulled back in the driveway.

Normally engine runs at 180 all the time.

It was hard to tell if water was flowing in the radiator as it was starting to rain, getting dark, etc. I'll look more closely tomorrow.

I forgot to measure the distance between T stat housing bolts so I can buy the right gasket when I get a new T stat. Can someone tell me that measurement? I don't trust the parts places to get the right one.

I haven't looked at the water pump removal process. Anything unusual or is it pretty much like any other pump?

I guess w/o the thermo in , that water pump would start rolling water right off.
You`d be able to tell.

Can't recall which motor you are running in your truck, which would identify which style water pump is being used. At any rate, water pump removal should be straightforward.

Just leave the upper hose disconnected at the radiator nipple and start the engine. If the pump is working, you'll know it right away! I worked on a little Japanese 4 cylinder engine once that had a stamped sheet metal water pump impeller which had rusted away to less than half its original diameter- - - -mostly nothing but the hub was spinning with the shaft. The only complaint the customer had was "The heater doesn't work right!"
Jerry

I took my old gasket to my FLAPS (it is a NAPA) to match up a couple of weeks ago. The guy just looked it up by application, a '52 GMC 228. Computer was right. I bought 3. I'm pretty sure that the same thermostat housing (and therefore gasket) is used on GMC and Chevys of that era. NAPA part # 1038-ST.

It was difficult to discern whether the pump was working or not by looking in the cap but when the upper hose was disconnected water came shooting out. So I think that's a pretty good indication that the pump is functioning.. of course it poured water all over the generator.

Of course now I guess my only option is to begin flushing this system and see what I can discover.

I did bring a partial jug of muriatic acid that I had laying around I'd say it's about a third of a gallon. What would be an approximate mix ratio? Or should I just pour it in and fill up the rest with water and let it run for a while?

With the engine running and the system full of coolant, and the radiator cap off, I can detect no movement in the water flow. I spit into the filler neck and the spit bubbles just stay where they are.

Yet when the upper radiator hose is removed water comes spewing out of it from the force of the water pump. And I know that the radiator isn't stopped up because when I do that it drains as it's being drawn into the engine via the pump.

Why can't I see movements when I look into the radiator?

Idling at about a thousand RPM just sitting here and the temperature hasn't gone higher than about 182 or 3. Of course I forgot to bring my infrared thermometer to look around for hot spots. And the spit in the radiator cap is just staying put

At higher RPM I definitely see movement in the radiator.

And the water is the color of chocolate pudding

At higher RPM the temperature has climbed to190-195

Water flowing out of the petcock on the rear of the block is perfectly clear. The coffee chocolate colored water was not thick it just seemed to be some dross floating on the surface and not a thick gunked up mess

That seems not right.

Time to check for a head gasket leak or a cracked head- - - -water pressure, air pressure, or a "block test kit" which uses an indicator liquid to detect combustion gases in the cooling system.

www.harborfreight.com/combustion-leak-detector-64814.html?

The test fluid sold by NAPA seems to work better than the supposedly same stuff sourced elsewhere, even O'Reilly's.

Jerry

Head gasket air pressure test- - - - - -
Get each cylinder to TDC on the compression stroke and lock the flywheel with either two pairs of vise grips at the bottom of the bell housing, or just put the transmission in high gear and chock the wheels front and rear. 100 PSI of air pressure through the spark plug hole- - - -watch for bubbles in the radiator.

Water pressure test- - - - - -
couple the top and bottom radiator hoses together with long flex hoses and a piece of PVC pipe with a garden hose adapter plumbed into it. Bypass the heater core with a loop of heater hose to both nipples. Pressurize the cooling system to 20-30 PSI with a garden hose. Remove the spark plugs and spin the engine with the starter. Look for coolant squirting from the cylinder with the leaky head gasket and/or a cylinder head crack. This test will also find freeze plugs that are rusted out and about to fail.
Jerry

In the event of a cracked head/cylinder or compromised head gasket, wouldn’t bubbles likely appear at the radiator filler while engine is running? That could be what’s causing the muddy froth in the coolant.

Some leaks only happen under load- - - - -not enough combustion chamber pressure at idle to allow bubbles to show up, so the engine has to be stressed a little. However, a leaky head gasket is like being a little bit pregnant- - - - -the situation isn't likely to improve anytime soon!
Jerry

OK, here's the recap with random pictures.

While running the engine and flushing with clean water, the water flowed out of the engine with a little rust on the surface - not thick brown sludge.

After adding muratic acid and running for awhile, the mocha-colored water flowed out of the radiator. This too was only dross on the surface and not thick sludge. I see in the photo that there were actually bubbles in it so maybe that's an indication of exhaust gasses.

I dared to open the engine block drain cock and to my surprise it wasn't crusted up or corroded and it didn't break off. I opened it with my thumb and forefinger without pliers. Except for an initial few drops of rust water, it immediately flowed crystal clear and continued to do so.

The rust seen when I removed the T stat seemed only to be a small amount , probably from the cast iron T stat housing. No real thick crud was found. Even though the pictures look like a lot of sludgy rust in the housing, it actually doesn't come off on your fingers after flushing.

Th inside of the radiator is shiny copper/brass color with no slime or crap coming off on my fingers when I stuck them in.

Even though I couldn't see water flowing in the top of the radiator - even at higher rpm, plenty of water chugged out of the upper hose when removed from the radiator.

The radiator drained as this weentr on I presume due to the action of the water pump. Can a water pump be only working at partial capacity?

It sure would be easier to replace the pump than a head gasket.

Anyway, after closing everything back up and filling the system with water only, the temp stayed at 180 while idling but crept up to 195-200 wihile driving around.

I'll perform the test(s) to determine whether a head gasket is leaking. I have to decide whether to do it 40 mi away where I have no tools and equipment and have to remember to take out everything I need, or have it towed back to Rancho Relaxo and do it here.

I don't want to risk cracking a head by driving it, even if I can keep the temp below boiling.

Don't forget to neutralize the muriatic acid with baking soda. Simply draining it doesn't stop the acid etching process.
Jerry

Jerry, I found a T with a hose connection on it that will fit the heater hoses. I''ve already bypassed the heater core. If I block off the upper and lower radiator hoses, I should be able to pressurize the system using the heater hose instead of the radiator hose, right?

Yikes. I'm not even at the truck anymore.

How much baking soda? I can have my mom do it for me. SHe has tons of the stuff for maintaining her pool.

Some additional troubleshooting techniques for tracing down a leaking head gasket or a cracked cylinder head or block:
- Shut down the engine and let it sit all night. When engine is stone-cold the next day, pull the spark plugs. In a leaking cylinder, small water droplets can appear on the spark plug and inside the combustion chamber/cylinder.
- When starting a cold engine, examine for signs of an engine misfire. A wet cylinder compromised with coolant can misfire when cold.
- Motor oil will eventually emulsify (milky appearance) when coolant leaks into the cylinders and eventually down into the crankcase.

Something bad happened by the look of that thermostat. I hope it is the water pump.
I get the feeling part of it internally failed and collapsed inside. In my trucks, with the cap off and pump
open you can see water rolling in the rad. Pressure or heat my be causing to appear to chugging out the upper

BD, It looks worse in the picture than it actually is. The crud on the T stat was just some rusty crud, probably from the inside of the T stat housing. I rinsed it off and put the T stat in a pot of water on the stove and it opened up as expected.

Is it still the full strength acid mix? Or a water flush after you dumped the acid?

Either way, I’d use a box of soda and the engine needs to run to mix it up.