The Stovebolt Site Forums The Shop Area Engine Shop 216 still hot

Hello, I'm still trying to figure out why my 216 is still running so friggin' HOT. It runs really NICE, but it boils over all the time especially when I shut it off. I have a new 3 row core radiator, a new (correctly installed) 160 degree thermostat. My water pump seems fine, I've even tried using "Water Wetter". I have all the original equiptment installed (fan, shrouds, etc.). I don't know what else to do, so I'm wondering if something is up with my head gasket. I'm gonna pull the head to see what's going on. Upon pulling the manifolds, I noticed that oil seems to be oozing out between the head and the block. Should it look like this? Am I on the right track? Thanks, john. [img]http://img.villagephotos.com/p/2003-9/378428/216head.JPG[/img]

John did you retorque the head gasket after the intial installation and engine warm up? Just wondering out loud.

HOw hot is it getting and have you verified this with an temp gauge in the radiator?

Just a thought, did you flush out the block before putting in the new rad? I just did this a couple days ago on my 235. Was amazed at how much junk came out of the rear end of the block. I'm told lots of crud collects around the number six cylinder.

It's definitly getting hot, 'cause when I shut off the motor I can hear it boiling from within. Note: the cooling system is a no pressure system. I bought the motor as a "supposedly" rebuilt motor that came with my truck (unrestored at the time). The head was already installed and I haven't retorqued the head. I did run a garden hose through the motor though.

There are some good sugestions on flushing the
block on Yachtcares post 7-20.
I wouldn,t pull the head unless you are blowing
coolant out the o-flow or getting it in the oil.
With a new rad. you could run a 7 lb. cap &
50-50 % a-freeze. A can of Bars leak will stop
that minor seapege.

John, I have a 216 that had the same overflow problems you have. When I first purchased the truck, I thought I would be a smart guy and top up all the fluids, especially in the radiator.
The loss of fluid may be the result of overfilling.

In the average cooling system, the anti-freezing solution expands approximatlely 2 pints on heating from 30 to 160 degrees F., and a corresponding space should be left when adding liquid to the radiator.

I reduced my volume of fluid in the radiator and I have not had a problem since.

As for your question about oil oozing, my truck is in very good condition and it still oozes oil in the location you show. Do not lose sleep over it!

remove thermostat. Refill with plain water and run engine. Stick a turkey or cooking thermometer into radiator neck and let idle. Watch for water flow and temperature climb until it stabilizes. Shut down if it climbs past 195 while idiling. Could be stuck thermostat, pinched hose, slipping belt, bad waterpump, wrong head gasket, etc.

Do a compression test. Pull head only as last resort.

chip

SOP would be to drain out the coolant, you could save for reuse if it's okay. Then do a two part flush or take to a radiator shop where they could flush it with the high tech setup. Be sure to check the thermostat, drill a hole if you don't have one to vent air from under it when filling up. If you have just been using water, excessive mineral deposits, salts, etc.. could have built up. The water pump packing will probably go out after the flush, but that could be rebuilt or replaced.
I lost a head on a gmc 228 because I could not flush out the water passages good enough at home. After pulling it, I was really amazed at just how clogged the head and block were. Hope this helps.

Might also double check the timing. I got a call about a 1940 Chevy Sedan that would heat up and boil before you could back it out of the drive. Found out the owner had been tinkering with the timing and had it way too slow. Reset the timing and no more boil overs. Might not help yours, but can't hurt to check.

Thanks all for the ideas.

Wrenchbender: My cooling system is a no pressure system. Meaning that even if I put a 7 lb. cap it would still overflow out of the vent tube on top of the top tank.

Niagara: Even if I run it 'till the coolant quits overflowing out of the vent tube it would start blowing lots of steam and I can still hear it boiling from within.

Chiphead: I have new hoses, I've checked the thermostat and even drilled a small hole on the flat part.

I've also checked the timing and tried a few other positions too. I've even adjusted the valves too. Am I still jumping the gun at pulling the head?

My cooling system is a no pressure system. Meaning that even if I put a 7 lb. cap it would still overflow out of the vent tube on top of the top tank.

The pressure rise increases the boiling point of the water, allow more heat transfer without boiling over. There is a 4 lb cap they intorduced in 52, with no other changes to the system.

I would check the water pump. First run the engine with the radiator cap off. When the engine is warm, does the water barely move? If so, check the pump impeller. Another problem can be the water moving too fast. I'm thinking Patrick's recommends a large pulley, but I'm not sure of the size. A smaller pulley will make the pump spin fast, moving the water too fast for good heat transfer.

Does water flow out the block drain? At the rear, drivers side, a few inches above the bottom of the block. If not, your water passages are pulgged, and need to be cleaned out.

Also, before pulling the head, try torquing the head bolts again. See if any are loose. That might be your problem. If not, then I would pull the head.

For what it's worth, when I had my radiator recored with a 3 row recently. The guy gave it back to me with a 4lb cap. Said that was all these ever needed. When I flushed my block a few days ago, I already had the head and water pump removed. When I applied water thru the rear holes in the top of the block, behind cyl #6, that was where the greatest amount of rust and sludge came running out. And I mean incredible amounts. I'm still trying to get the rust off the driveway. Flushing thru the front of the block from the pump opening DID NOT remove any of that junk. I am still considering pulling the freeze plugs as Wrenchbender suggested, and doing another flush, even though I did not have overheat issues with the half clogged one row that was in there. I know it's alot of work, but my vote would be to pull the head, and flush it right.

John,sometimes engines overheat because the idle speed is too low.What RPM is your 216 running at idle?

Is your ignition timing correct?

Is your fan belt loose?

Could it be you have an air lock in the block? It is suprising to me that you can hear it boil in the block. I have a 216 in my 37, But for the life of me I can't remember if I have a thermostat in it. I know I run about 180 to 190 on a 95 degree day. I guess the things I could think of is:

Air lock
The impeller is corroded and not circulating
Pulley slipping on the shaft
Bad New thermostat
Collapsed hose (I know you said new)
Sludge in the block
Wrong head gasket? I have never heard of that one though on a 216.

I think if I was going to take the route of sludge, I would knock out the 2 side freeze plugs, stick a hose in it and keep flushing. I got alot of stuff out of mine doing that. Beats taking the pump off etc...

Good luck, I would like to hear what the final problem is.

Brent

What is the temperature while running down the road? What is the temperature while just idling? Does it boil over while running or after shutting down after a run?

I really appriciate all the ideas that I'm getting. It makes me feel good that someone cares. :rolleyes:

Niagara, I've upped the idle and checked the timing. My belt is okay.

Dan, I can't rely on my guage it's really inacurate. But I know it's overheating 'cause by the time I stop it's boiling over whether I'm rolling or stopped.

Fred, I tried 2 different water pumps. I guess I'll check the rear drain plug and see what comes out.

If it's gunky, maybe I won't have to pull the head and just flush it real good.

Thanks all for the ideas. john.

Run a compression test. All clyinders should be 10-20 lbs of each other. This will check the integrity of your head gasket seal to the clyinders although the engine runs good with power? Do you loose coolant as it runs?

Considering what you have done to the engine and it is still cooking off, my bet is you have a cracked head. Chevy sixes crack around the exhaust valve seat and will cause them to run real hot.

Have a machine shop clean and magnaflux the head after you get it off.

Do you see many bubbles in the radiator with the engine running before it completely warms up? Does it boil over on cooler days or just on hot Sacramento summer days?

You should have a drain cock near the back (firewall) of the block. Take this out and use a coat hanger and poke around the water jacket. Then flush from the upper hose with the lower blocked off. This way the water will come out the back of the block. Good luck

Could the head gasket be "upside down" blocking some of the water outlet holes in the head?

John, you mentioned that you tried 2 water pumps.

Have you observed any leaks in the area of the water pump?

The water pump seal must be leak tight, not only to avoid loss of liquid, but to prevent air from being drawn into the cooling system. Aeration of the cooling liquid causes foaming. I wonder if this is the sound you are hearing bubbling within your engine block?