extremetoy

iTrader: (17)

ive got a s10 w/ a basically stock lq4 in it (small 222/222 cam) and the coolant is boiling once it gets right above 210. i put a new 16lb rad cap (stock replacement at local auto store)
i was using a mix of 50/50 coolant and water now im using all water with water wetter (it was doing it w/ both types of coolants.)

any ideas whats up?

thanks, Gary

LS6427

iTrader: (2)

There is air in the system if your coolant is boiling over. Most likely culprit is a blown head gasket(s), thats just about all it can be really. No other way for air to push its way into the cooling system.

Coolant can reach 270* and it still won't boil over if the coolant system is properly sealed.

And you should never use 100% water, you should have half a jug of Dexcool in there with the water and water wetter.

extremetoy

iTrader: (17)

i just built the motor, the headgaskets are new, no oil in the coolant and no coolant in the oil, so i dont see how it could be a headgasket problem

LS6427

iTrader: (2)

OK then. The only other thing that can be going is that you already have air in there.

Did this happen right away after the enigne was installed or have you been driving around for awhile and its been fine, and this just started?

extremetoy

iTrader: (17)

basically ever since i put the motor in

extremetoy

iTrader: (17)

could the waterpump have anything to do w/ it if it is bad

LS6427

iTrader: (2)

Then I would do this:

Start the engine with the radiator cap "off". Stand there and wait for it to heat up enough until you see the coolant start to flow. Hopefully the level drops quite a bit when the t-stat opens and the flow begins. Simply top it off with more water/Dexcool. As the cooler coolant flows into the block/heads the t-stat will close and the flow should stop. Wait for it to heat up again and start flowing once more. Top it off again. That should get all of the air out of the system.

I would also take the 10 minutes and remove and reset the t-stat. Just take the bolts out, pull the housing away from the block and put it back. Then do the above process.

LS6427

iTrader: (2)

Well, you will know if the pump is bad when you do the process above. The coolant will never flow.

BUT.....coolant should NOT boil, period. If the coolant system has no air in it and is properly sealed, you will blow a hose off somewhere before the coolant boils over.

LS6427

iTrader: (2)

A very fast way to see if the pump is working is to take the t-stat out of the housing and bolt the housing back up. Take the rad cap off, start the engine and it should be flowing immediately. Then you can put the t-stat back in and the pump is ruled out.

extremetoy

iTrader: (17)

the reason i was asking about the pump was because before i put it on i noticed it had residue comming out of the weep hole but i used it anyways, but it hasnt seemed to leak

extremetoy

iTrader: (17)

could it be the fact that i have my throttle body bypass line tee'd into the overflow line? could it be sucking air from there?

LS6427

iTrader: (2)

Don't know, but why do that?

extremetoy

iTrader: (17)

theres no bung off of the radiator to plug it to and it seemed logical (and easy) at the time.

now that i think about it, i think this is the most logical reason where its getting the air from since its like the highest point in the system ill switch it up tomorrow and see if it fixes it

thanks, Gary

LS6427

iTrader: (2)

Yeah, try that.

And get some Dexcool in there, that will also keep the coolant cooler than just water.

5.3LJimmy

iTrader: (10)

You need to put a reducing tee in the heater hose to connect the air bleed line to. it will definitely not work hooked to the overflow. If you have been driving around like that you may have blown a head gasket also.

extremetoy

iTrader: (17)

well i fixed it and it seemed to fix the problem as well

why would that blow a head gasket? its not showing any signs of a blown head gasket and still no oil in the coolant and no coolant in the oil so im assuming that they aren't blown?

Op4

Man, I think I am having the same problem. I have an s-10 with a 99 LS1 and it has been bubbling coolant out when I take off the cap. I have an afco radiator that did not come with a place to put the TB coolant line.

So did you T the heater hose and hook up the bleeder hose there to fix it?

Thanks!