If you remove the cap very slowly and carefully, with a few rags between it and your hand, it will not "explode."  If you are not careful about it, then yes, you are getting burned, probably seriously.  This is where the infrared thermometers are really handy.  No need to risk removing the cap on a hot radiator.



Lawrenceville, GA

I checked all the sparkplugs today, they all look fine, some are kinda rich but there's no weird foam or white color or any oddness like that.

A friend of mine is suggesting that maybe due to high heat or other reasons, a failure occurred between the water jacket and the nearest cylinder. Does this sound like a possibility? He admitted he didn't know much about yblocks.

I fought cooling problem on my 55 for 2 years turn out that it had a 5 1/4 inch water pump pulley on it, which moving the water through rad way to fast/check your pulley should be 7 1/4 inch
jim

So - If you simply run the engine up to temperature in the driveway, with the hood up and the radiator cap OFF (you could drive it around the block with the cap loose too) - then have a look down into the tank. What is going on then? A blown head gasket is to be suspected due to the "white" exhaust comment - bubbles would then be pumping into the upper tank - a visible sign for sure. You might have to add some water to get a good look. Losing exhaust into the water jacket can make the coolant very hot - very quickly.

I don't have direct experience with the sedan engines that have no waterpump spacer (T-birds are bad) but there should be signs of water moving in the upper tank when the thermostat is open. We had a fellow write in here one time (with a sedan), and his engine had an old waterpump where the impellor had sat and rusted so badly (vanes were missing and filled with gunk) - it simply wasn't pumping enough water. This becomes more serious with an auto trans - sitting in gear against the brakes - rpm is down low and both water pump and fan air flow is minimized.

I did notice in your photo of the thermostat - that it is the one with the 1.0 inch poppet - and that is a known flow restriction. The best one I've found is the "high flow" version - 160º temp - from Mr. Gasket. Mine opens wide and reliably at the rated temp - there is also a larger opening model available at NAPA that opens at 170º. The Y-block thermostat OD is the same size as a big block (426 - 440) Chrysler and sometimes easier to come by than asking for a 272/292/312 part.
 

 
 Steve Metzger       Tucson, Arizona

Thanks for the advice, I'll take it. I do want to correct one thing, I meant the intake manifold not the exhaust manifold. The idea is I think one of the two front water jackets is leaking across and into the intake of one of the first cylinders (1 or 8 I believe) If so, it looks like the coolant is getting burnt up and exhausted as there was wetness in the tailpipe. My buddy also once he saw the smoke said it wasn't white smoke like I thought it was.


Oh also the car starts right up like one or two seconds of cranking, he said it wouldn't start up that easy with a blown head gasket.

I sure hope my block isn't cracked..  I haven't had a chance to take my intake manifold off and check for leaks in the gasket. I'm just hoping it's not.. cuz I'll be screwed.

When my 55 was all original the temp gauge read almost all the way to hot even though it was close to 180.


Butchering up everything I can get my hands on in Dayton Ohio

stuey is the one that is most likeley corect,white smoke is a good indicator along withover heating of head gasket isues.

Well I got the water pump off today, nearly killed myself it felt like.. it was so friggin hot today. I ended up having to take the radiator off just to get the pump off. Though I'm pretty sure you guys already knew that, wasn't a huge deal since the system was drained already and it's only held on by four bolts. Hell, having it off the car will probably make it easier to flush it with a garden hose or something.


The pump looks okay considering, though it does have a bit of sludge along the back-plate where it meshes with the front of the block. It's pretty gross looking, kinda looks like mashed up green flax seeds. I do gotta say, those pumps sure do have dinky little impellers in them don't they? No wonder if it's not circulating very well. I'll post some pictures up here in a bit. I kinda wish I could get the pump taken apart, but I don't have a puller to take the hub off.