8 replies to this topic

[crazylarry12345]

I just bought an s10 with a 355 when i take it iut it pushes water into and out of the overflow bottle it is suppost.to be a fresh motor it only has a 6 lbs cap and does not appear to have water in the oil i dont want to just start tearin the head gaskets out of it

[starboyshady]

Try a racing cap , I think they are 21 & 28 lb . Is it hot when it pushes the water out ? Temp of engine , I meant .

[The Legend]

6 pounds is retarded but if it has a stock radiator with plastic tanks I wouldn't try a 20 plus

[racepace]

You could try putting a washer in the thermostat housing for now. You may be getting too much volume gushing through.

[crazylarry12345]

It is not hot when it happens, its a alum rad no plastic ill try those things thanks i will keep you posted

[racepace]

Or a different sized pulley driving the water pump to slow it down?

[BUTTBEAK]

Since it is not hot when this happens, You likely have a connection from the combustion chamber to the cooling system. Likely cracked head between seats.. or lifted head gasket. I would not use a higher pressure cap, you risk pushing the coolant into the combustion chamber after shut down and further mechanical damage( hydro lock-bent/broken rod).

 

I would remove thermostat for the further test/s.

 

Fill the cooling system, a steady flow of bubbles from filler neck once you get the system filled indicates combustion pressure entering the cooling system.

Another simple test if you have a tailpipe emission test machine at you disposal is to "sniff" the rad with the machine, if you have HC and CO you have a interconnect, gasket or crack.

ALSO Make sure the water pump is not intended to be rotated the other direction ( don't know if they ever did that with SBC, but is not  uncommon when engines that use a serp belt in some applications. Look into that, the impeller will be different) .

 

You may want to check the casting #'s on the heads, some are notorious for cracking.

[jo73]

Bad cap. Bad radiator. Clogged radiator. Water pump rotation. Crank/water pump pulleys. Wrong intake gasket, restrictions flow. Heaď/ heads worpped or cracked. That search can be a pain in the ash. And don't forget costly.

[crazylarry12345]

Been messin with it i put a 18 pound cap, but as soon as i start it even cold with the cap off it starts bubvling out. Startin to think its a head provlem, gasket or crack. Thanks for all the responces