Head swap problems

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Jan 5 2007, 01&#58;52 PM) [snapback]78414[/snapback]</div>

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When you pull the stat, drill an 1/8" hole near the top of it as an air bleed if there isn&#39;t one already. I think I remember Dustin saying something about pulling the upper rad hose off the radiator, pour coolant into the hose until fluid starts coming out of the top of the radiator.
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I&#39;ve done both...

As for flow with passage blocked, yes I got flow. I hope it&#39;s not the pump, but I know of a couple LS1 powered formy&#39;s that currently have cooling issues today. Pumps aren&#39;t that expensive (&#036;120) at the local parts store.

sounds like you done everything right, I would definately say it has a vapor lock due to the head swap. I seem to have the best luck with squeezing the heck out of the upper and lower radiator hoses like your pumping them up or something. this should be done with the cap off and the engine running. Youmay have already done this but if not its worth a shot. When i purchased my first ls1, the thermostat was froze....I had to go purchase a new one from gm. Im sure that isnt your problem but thought i would add that i have saw them freeze.

There&#39;s not a lot that can go wrong with a pump, the impeller blades can corrode off and that&#39;s about it. Anything else and it&#39;s catastrophic failure or water pouring out on the ground from a weep hole. I hear the new stats are designed to fail in the open position somehow. I&#39;m not sure how that works but our BMW&#39;s stat is stuck wide open and it takes about 15 minutes of driving to warm up the engine and it gets too hot when parked with the engine idling. I&#39;ll be replacing that one tomorrow. Park that dude with the nose high so that the air bubbles come to the front of the engine, remove the air bleed plugs and start filling the engine through the upper radiator hose as mentioned earlier. When you quit getting air out the bleeds, block them off again. Fill the engine until water runs out of the top of the radiator and then slip the hose back on it. It should be full enough to have the reservior automatically fill the radiator as the engine cools.

I wonder if it could be a bad set of gaskets that they failed to punch out a couple of holes? You should be getting water out of all four corners when you fill it up with the plugs removed.

Get one of the rubber tipped air nozzles and blow into the air bleeds and see if it comes out somewhere else, if not you&#39;ve got something plugged somewhere.

Cooling problem is solved and the beast is alive...............Seems the system was vapor locked. I know this isn&#39;t a common problem but I drained the system down, pulled off the upper radiator hose and filled it with coolant holding it as high in the air as I could to let head pressure push the air out. Once I knew most of the air was out I pulled a fan relay and let her heat up and the thermostat opened&#33; I&#39;m running a little lean at idle but I&#39;ll fix that. As far as hauling ass goes, there&#39;s no problem there. I can&#39;t wait for someone to mess with me. I now have a full blown LS6 plus with the mods and matching numbers.

Thanks for all of your suggestions and help. Eliminating all possibilities is how we work these things out.

Sweet&#33; Glad it was that simple.

Hey, Red... I said pump b/c a co-worker&#39;s LS1&#39;s pump is busted. Guess what... formy sounded like something was grinding. Swapped the pump, and problem gone.

Sucks to be stomped by the simple stuff, but always end up happy not spending a life&#39;s savings fixing problems.

I hear you on the bad pump. My cooling problem on the BMW was a defective stat. I took the water neck off and the stat fell out in pieces. :bash: POS bimmers&#33; :laugh: