Is it possible for a waterpump to be bad when you see coolant flowing with the cap off? Also when the water sucks down into the radiator when you start the car. Car started overheating, thermostat was damaged. Replaced thermostat. Car will idle for 10-15 minutes at 165-170 then coolant starts to boil out of the overflow resivior and the temp goes up. Ultimaitly boils itself dry and overheats. Bled the system with heater on until nothing but water streams out of both valves. No coolant in oil. Coolant level stays the same until it boils out of the overflow.

 

did you burp the air out of the system?

 

Have you tried a new radiator cap.

 

had a similar issue, ended up being a clogged radiator.

Instead of just bleeding it, try back flushing it. It's a $4 kit from autozone. Everycar I've had, has one of these on it.

 

Get under the car and see if there is any coolant coming out of the water pump at the weep hole. If there is the water pump is no good. Definitely want to take of it before it gets on opti.

 

the number one most important ting that needs to be addressed is bleeding correctly. You say that you bled it with the heater on. This implies to me that you bled the system with the motor running. This is wrong.

 

trying a new cap tommorow, bled it wrong?....I was always told to fill up the pump when the thermo is out, then top off the rad.....start the engine and open the lower bleed valve until only fluid comes out, then open upper valve until fluid comes out. Shut off car, re check levels and reset the cpu light. always worked before.Is there a better way? The rad is new. thermo is new, hoses are new, cap is 1 year old. pump has somewhere between 75k has 150000k. no water coming out of peep hole.

 

the water pump is moving water. One side is suction and the other is discharge. If you open the bleeder with the car running, it will suck in air.

The correct procedure is to simply fill the radiator, open both bleeders untill it runs stead, then close. start the car for about 30 seconds so the pump can run. Refill, repeat, and then cap it off and take it for a short drive. Let it cool and then check teh level again.

Again, just make sure that you only open teh bleeder with the car off. Otherwise it will just pull air in. There is a funnel adapter commonly available that works VERY well on an LT1. It hooks to teh radiator and lets you fill the funnel. This means that you have a lot of force, higher then the bleeder pushing coolant into the system. If you use this while bleeding it will force air out much much more effectively then just bleeding alone. It's a wise investment if you can fine one Lisle makes one, along with several other companies.

 

the full story is posted in road racing forum under track day disaster. I sent it over here to see what you guys might think.

 

I will try that tom after I put a new cap on it, thanks HBH

 

sure, let us know how it goes.


Also, not sure if it's still out, but get the thermo back in. it's the only thing that will seal the housing, and due to the coolant routing free, it can actually hinder flow to the motor and cause problems.

 

Ok, replaced thermostat...one new one for another....and put a new GM rad cap on it. Bled it correctly...car idled for 25min at 165. Noticed something new though, a small but constant wisp of "steam" coming from the coolant resivior. Kind of like when you put a ciggarette in a bottle. It remains constant no matter what RPM the engine is at. So, I smell it and guess what, it smells like gasoline mixed with oil. Kind of like what you would invision the intake tract of a head to smell like. So, I want a second opinion and decide to drive it down to my local speed shop, I make it 100 feet and the car starts backfiring and getting hot real quick. I immed turn around and head back. It backfires off idle and surges, within 1 min it went from 165 to 200 and is rising stead, as soon as I park it again I notice water spewing from the overflow tank again. At this point I am thinking head gasket...

 

you can pick up a "block test kit" from napa for about 40 bucks and test for exhaust gasses in the system.

 

Oh, yea,......full of all kinds of ****. Pulled engine apart today and found soot in ALL the coolant passages. Spark plugs look nuclear......time to build an engine.....yay