Finally found the fix for the overheating problem and as many of you speculated, I am absolutely relieved and pleased. I no longer have an espresso machine on wheels..

I have to go back through the posts to see if anyone thought of this and I missed it , but I don't think so.. if you did, I will send you the prize for sure!

The Harrison expansion tank return from the rad (the overflow hose) had a tiny crack in the fitting that was not noticeable when cold and quite honestly there was so much fluid flying when it was hot that I couldn't tell. This crack allowed air into the system when running and , Hey Presto!, the engine overheated and then - Barf-A-Roo..

Thanks to everyone for the help and thoughts, the race water pump was not the problem after all, but as it is off, I think I will not tempt the fates..

This was really frustrating on about 50 levels, especially as a lot of guys pointed out - there are only really 3 parts in a cooling system, a pump, a rad and water. If you want to feel like an idiot , as I did, sit back and contemplate those three parts and quiz yourself on why you are too dumb to figure out what seems so basic...

I will go back and see if anyone thought of this, otherwise I will think up some other way to award the prize I bought...

The fitting on top in this pic..



Here are the other threads:

http://forums.corvetteforum.com/c1-a...lem-redux.html

http://forums.corvetteforum.com/c1-a...tough-one.html

 

Great work. Now enjoy.

 

Congrats on finding the problem. I've been following your saga with great interest. May we assume that your avatar will soon change from car on trailer to car on road?

 

Thanks Gents!

Yeah I will change the Avatar soon

 

Congratulations! That has to be such a relief. Now you can have some fun.

 

How did you find the crack?

 

 

Glad you found it. Now you can enjoy your summer!!!

 

By the usual way - you make a mistake and a brilliant discovery follows..

Filled the system with the front end on jackstands and was taliking on my cell and not paying attention - overfilled by a lot and as the opening was tilted back, why was water running down the front?

You go through a lot of emotions when that happens..


Thanks for the good thoughts everyone...


You are correct, now I will enjoy the summer 53 BF!

 

Had anyone suggested a Pressure Test. If so it should have revealed the crack. Al W.

 

Well it's about time ! Only kidding. Glad you finally found the problem. I've gone through similar situations where you do everything imaginable and it still doesn't work. I guess the only thing to add to the thread(s) as something to do in this situation would be to put some dye in the water,. and see where it leaks out

 

This problem generated the mother of all threads on cooling systems. Expect your travails will help many future "hot & bothered" CF members.

 

I guess you've taken a test drive and confirmed you've fixed your problem. I'll be mightily suprised if you've found the real source of your problem though.

I thought from the start you had a coolant blockage and then entertained the possiblity of your cooling system sucking air. The problem here is, the crack you found isn't on the suction side of your cooling system.

For example, what is the difference between the crack you found in the nipple and driving without your radiator cap on the surge tank? It won't suck air in with the cap off and that nipple is exposed to atmosphere with the cap off when the surge tank is at normal level.

 

I agree with MikeM. I doubt this was the source of your problems.

Jim

 

Your avatar WAS your definition of trailer queen...

I hope that was your problem...if it is im glad you found the manufacturers defect..

jack

 

hmmm, trying to get my head around this one - recall that the SB rad itself has no cap, the pressure cap sits on top of the expansion tank, it ain't no overflow tank in the usual sense. A leak anywhere on the pressurized side of the expansion tank (i.e. the tank, and the lines between it and the rad) will give rise to a no pressure situation in the system, and as we cooling system experts ( ) know, that can cause probs for cooling, both due to the premature loss of coolant, which is itself bad and is replaced with air. I guess what Mike is saying is, this could only lead to so much loss of coolant, and not a big enough loss of coolant to make a difference, because the crack you found is at the top of the surge tank (and thus, it would not itself be responisible for the surge tank going dry??

so, I need MikeM (whose opinion I certainly do respect) to edumacate me a bit

 

The crack let additional air in that cannot get in when everything is sealed. The coolant puked when it boiled and did not have to get as hot to do so when there is a loss of pressure- it works fine now and that is the only part of this mess that I care about... it was the only absolute defect we found. It also does not barf anymore after some driving in much hotter weather - it is almost 90 here now.

So glad I had the engine taken apart and reassembled


Thanks again for all of the input guys, really - that was super!

 

You have already figured out my line of thinking, Jack.

Looking at this another way. The surge tank cap is vented so when the engine cools, the coolant contracts as it cools. As the coolant contracts, it is displaced by air drawn into the surge tank, through a vent in the surge tank cap. Otherwise, when the engine cools, all your hoses would collapse if the cap didn't vent. The cap venting gives the same result as that cracked nipple except the cracked nipple would leak under pressure. Otherwise, same/same.

 

Actually, that tank IS (or should be) on the suction side, as the lower fitting connects to the top of the water pump, Correct? A blocked or partially blocked small line from the top of the radiator to the small fitting on top of the tank would exacerbate the suction problem.

And I can tell you, with absolute, 100% guaranteed certainty, that if you install that tank on the pressure side of the pump, (bubba rigged into the heater hose system, the wrong way) it will most certainly fill up fast and blow water in mass quantities out the radiator cap as soon as you get some motor RPM going. Ask me how I know.

Come to think of it, maybe you do have the tank installed wrong and you are feeding it high volume pressurized water, which cracked the fitting after the small line to the top of the radiator got plugged with something at 120 miles running.

Double check your hose routings to be sure.

Doug

 

man tin tin...i really hate to rain on your parade but i dont think you have found the culprit....i hope it all works for you as you know and maybe the re assembly will prove ok but that surge tank nipple wouldnt cause the problems you described...good luck were' all pulling for you....