The Stovebolt Site Forums The Parking Lot Big Bolts strange overheating problem

1949 Chevy ton and a half.

I had a slight head gasket leak of engine coolant. I put in a bottle of that liquid stuff with the gooey plus the metal flakes. It stopped the head gasket leak but then I started having an overheating problem. I took the radiator out and it was full of globular slime. I finally got all that flushed out. The thermostat was also goobered up with slime. Checked the water pump and it looks fine (see below). Still had the overheating problem.

So I tore it all down again, made sure water would run through the radiator as fast as I poured it in. It does. Put it all back together.... still overheats. Tore it down again. This time I ran a roto-rooter toilet snake through the water jacket of the engine block. Got caught on that stupid oil line that goes through the water jacket. (What a dumb thing the engineers did.) Got out the air compressor and blew air in one hole of the block waterjacket and it comes out the other hole. I haven't put it back together again yet because I only have one more water pump gasket.

This is what I believe: either a) there must be (have been) a gooey blockage inside the engine block water jacket or b) the water pump suddenly stopped working just at the time I put in the gooey head gasket sealer stuff.

My question is this. The water pump impeller turns when I turn the pulley. The impeller looks to be cast iron and has all the vanes intact. It seems darned unlikely that the water pump on that thing can fail! Has anyone seen a water pump of this type fail?

Harrell

Harrell,

If you eyeballed the pump and it looked good, it's good. Overheating problems are almost always the result of a plugged or rotten radiator or a thermostat that has failed to open or is getting sluggish in opening.

It is also possible that your thermostat was air locked on your second attempt and in reality your overheating problem was cured with the first douche.

If there is a problem, my bet would be on the radiator. I'm not sure that your flow test was a accurate representation of a clean clear radiator. That's my guesstimate!

Stuart

Make sure there isn't any of that slime stuff on the capulary tube for your gauge. Maybe it's sending a false reading. You can also check component temperatures with those laser thermometers to see if anything is actually getting hot, and where,
Scott

or you pluged the water pump up with the sealant and ruined it that way.....


there is a "steam hole/drain hole" in the pump housing, when they fail they will leak form it. if it failed when you had it chocked full of the sealant it may not show it.

As Stuart suggests, it might be possible that you developed an air lock at the thermostat. A mechanic friend I respect routinely drills a small hole in the plate of every thermostat he puts in any engine which ensures that you avoid getting air trapped on one side of the thermostat. As cheap as thermostats are, you might consider putting a new one in. You can always test your old one using a pot of water on the stove -- just watch to see if it opens as the water heats up towards the boiling point. Best of luck.

I never use the stuff heard to many horror stories like yours.
Have also heard not seen that the can plug the plumbing in the motor itself don't know if its true but maybe.

Harrell,

I'm with the air-locked thermostat idea. Check out this recent thread on the subject:

"Water not circulating"

One thing that helped us was the Infra-red thermometer. You can use it to quickly check the engine temp below the thermostat housing and above the thermostat housing. If the block reads 170 with a 160 thermostat in (or 180/190 with a 180 thermostat in), BUT the radiator and the upper hose are not nearly as hot, THEN the water is not circulating through the thermostat.

The hole in the flange of the thermostat housing is a good idea, just keep in mind that the hole can get plugged up with stop-leak too, and you can still get air locked.

Hope this helps. Post your results!

-Michael

Thanks everyone. It's fixed now - I'm not sure exactly what the problem was, but it wasn't the radiator. It needed to be cleaned out because it had a lot of goo in it. But after I cleaned it out, the problem still existed. Then I ran a roto rooter toilet snake through the water jacket of the engine block AND took out the thermostat. The thermostat was new. Those last two things (running the toilet snake and removing the thermostat) allows the engine to run without overheating.

It certainly could have been an air pocket behind the thermostat. But, the radiator, water pump and engine block needed to be cleaned out to get that gunk out. The sealant did its job of sealing the tiny water leak from the head gasket. And although I had to do a lot of work, it was still less work and more comfortable work than pulling the head again.

Harrell

P.S. Had I pulled the thermostat first, it would still have overheated because the radiator had so much gunk in it. I was astonished to see all the goo that came out of the radiator.

HS

Harrell,

Always feels good to get it figured out! And now, you'll be happier, just knowin' yer radiator and engine are cleaner!!!

Wonder if that roto rooter thingy could get all the gunk out of me . . .

Congrats!!!

-Michael