Rust in Cylinder Head

[mud pie]

My father, way back when, put a new thermostat in.  Unfortunately, he didn't put it above the retainer...  So, during my project of getting the Willys running after all those years in the garage, when I pulled the elbow off the engine, I saw the thermostat * sideways in the head.  Thanks, Dad, rest in piece, still love ya.  When I peered into the head, I saw, what appears to me, to be a lot of rust.

Since I just got my radiator back from being re-cored, I'm not wanting to plug it up.  Is it normal to have rust in the head and I'm creating "rot-rohs" that don't exist ?  Should I pull the head and have it flushed ?  If yes, is this something I can do myself, or is it time for a pro ?

Or just run it (whenever THAT will be..) and keep flushing the cooling system ?

[Carls_jeep]

Chances are if there is rust in the head there is rust in the block. You can leave out the thermostat and run a hose from the head inlet to a 5 gal bucket and a hose from the water pump pickup into the bucket and fill the bucket with water and radiator flush. Then run the engine until it comes up to temp, shut it off and let it set until cool and then run it again. You could do that several times to try to flush the residue out of the head and block. You will want to open the pet * on the block and drain the block after that and you could even stick a water hose in the thermostat header and run some water in to flush the block.

[Doug]

Mine's pretty rusty in the coolant passages. �But it has never been a problem. � If it looks like chunks are going to break off and be floating around, then clean it out like carlsjeep said.   When I was rebuilding my engine, I found a length of wire coathanger inside my block.  I think the previous owner was trying to use it to scrape off crud in the passageways and dropped it and just left it.  I pulled it out during my rebuild when I saw it through one of the exhaust stud threaded holes.    

[mud pie]

I'm hoping it's just in the head, as when I drained my block prior to removing the radiator (which was bone dry at top), the block coolant came out nice and green; not rust colored at all.

But, my block has been dry for the past three weeks waiting on my radiator to be re-cored. I hope the rust hasn't progressed, even though I capped off all openings and my Willys is in the garage warm and dry, while my daily driver (smart cabriolet) sits outside. �Hint: when dropping it off for repairs, don't tell the shop to "take your time", because they will !! � :-/

I was thinking, worse case scenario, was to pop the head, let it sit in a tub of Evapo-Rust for 30 minutes.  Anyone ever use that stuff ?  Supposed to be the bees knees for things like this.

[Carls_jeep]

Evapo-Rust does work but you have to get all the loose rust off before it can do it's job.

[Bob W]

When I was rebuilding my engine, I found a length of wire coathanger inside my block.

Sometimes lengths of wire were included inside the sand molds that the blocks were cast in. The wire allowed for easier breakup and removal of the sand inside the engine and remained when it was done.

[Doug]

Bob, now that is something I would have never guessed or thought about.   Now that you mention it, I am betting that was the source.    I wonder if I should put it back in my block for authenticity?