From the GM service book:

 

If your radiator hoses are pressurizing to the point of explosion with the cap on, you have combustion leaking into the cooling system. There is no mechanism that can increase the water pressure past 16psi other then heat or a leak from the combustion chamber alone. And the amount of heat required to achieve the burst pressure of your radiator hoses would be plainly obvious is the car overheating.

The system is self bleeding, there is nothing required for you to do to get the system to fill up with coolant other then running the car with the tank cap off and filling as necessary. Ive done coolant flushes and refills and radiator changes and stats on plenty of these cars as well as plenty of other sealed GM systems and none of them have required bleeding.

Have you tried running the car with no thermostat at all?

 

Alrght

Drilled a 1/8 hole jn the tstat like everyone els did online

Now the car will not get hot and still no heat in the vents. Virtually no pressure built up in 20 min of running and driving. Means my headgasket and block is fine. But how come no pressure ks building?? Surge tank cap take a **** and leting air out? Or am i missing something here

 

Oh yea. Meanwhile my car was in pieces i gutted the cat, and its runnin and sounding better than ever. Lol

Why no pressure

 

J am not losing coolant anywhere. Staying steady

 

Ok idk what you all did so far, I didn't really read it. When I changed the tstat on my LNF, it took forever for it to bleed all the air out. I mean foreeeevvvveeerrrr. I idled it and reved it with the cap off, then took it for a slow spin. The coolant was in the 250s and no heat, then all of the sudden something cracked and the coolant dove 30-40 degrees down and I had scalding heat . Then the heat went away and the coolant returned to 250s. What I believe is happening is there is an air pocket by the tstat in these cars. As anyone who has taken Thermodynamics or Fluid Dynamics should know, air is compressible where coolant is not, air also doesn't transfer heat as well as most fluids either, therefore the air will have a harder time cracking the tstat open because as it heats up it just compresses itself. My coolant didn't completely bleed all the air out until I drove it for maybe an hour.

 

Yea after 45 min my temps are in the 90 celcius right now. Took a long time. Still no heat though
About 10 more degrees and tstat will open

Oh its holding a steady amount of pressure now. Still no heat

 

Did u have cap on/off and heat on/off when ura finislly popped??

 

Slowly getting more and more heat temps staying 97-100 when driving whicj is nornmal for a 98 degree tstat

Giving it a rest to settle ad hopefully it can push all the way out

Fingers crossed

And **** my life this l61 LOVES a gutted cat. Hasnt been that long since i drove it but i dot remember ot having this much get up and go

 

One thing to note: having the heat on or off does not affect the flow of coolant through the heater core. The cold/hot knob on the HVAC only moves a louver that controls how much air flows through the heater core. Coolant flows through the heater core 100% all the time.

However, it can be a good indicator of where your problem may be. Coolant flows through the heater core even if the thermostat is closed. If your engine is hot, and there is no heat coming through the vents, then your water pump is not moving coolant.

 

Brand new water pump working perfectly
I xan take the drain plug out of it running and coolant rushs out.

 

Not even sure if it is possible with our cars but any chance you installed the thermostat backwards? That can really delay or even prevent the opening when combined with an airlock

 

Not possible
I tried

 

Something is being left out of this conversation, you cant have excessive pressure, no coolant flow, no heat, and overheat at the same time. Seeing as how these radiators are sealed, theres no way for you to look through the top of the radiator cap for coolant flow, and you cannot judge whether or not your waterpump is working by opening a bleed screw on the bottom of the water pump, which i didnt even know we had.

 

There is a drain plug

And here. Go take te plug off with the car off. Observe... Now start the car and take the plug out.
My water pump is working


And before i drilled the hole. My car qas ovet heating, builidg way too much pressure, and no heat

Since i drilled the tstat. My temps when driving are around 90-100, theh go down when ideling....? I dont fkin know. And there is heat. Not as good as it should be, but its there. I am still having a prblem with the system maintaining pressure. I opened the hood after driving awhile and no pressure, yet temps wete OK to say the least, snd heat was working but would die off if ideling and on max

 

Right now its idelig and been so for 10 min and temps are town to 67. Im gunna burn this thing
To the ground soon

I have no fuxking idea whats wrong with it. I replaced a tstat and it never ******* worked right again. I spent hours on it, tore it apart tryig to find a problem and came up with nothing.

Everything that has anything to do wih the cooling aystem has been ripped apart and inspected. Only the rad and headgasket /cracked block are only things i havent got into, annd after todays run the rad is fine. This air locked kicked my ass BAD left right and center, even riped my ***** off and threw em way or the motor its self is fucked.

 

Betting your head gasket and block are just fine, you'd have to be losing coolant if either of those were the case. You live near Powell, take a road trip over there with it and see what the old man thinks.

 

who is powell? where is this? a shop? in or around thunder bay??

not that powell raceparts is it? in port perry? a full days 20 hr + drive? haah :P

 

powell is a guy out of canada who.works/ed with gm racing and makes and installs awesome racing parts. one of the most knowledgeable and valuable guys for out platform on this board

 

anyone wonna buy a car?

 

I'll buy parts lol

 

stock 05 l61, i maintained the **** out of this thing, everything got replaced when gone / on its way out.

annnnd thats how i came across that old shitty tstat, and got in this boat. and worst part is after putting a assload of time and money into this car + buying a suv and getting that on the road im pretty well tapped out for funds. bought the suv like 3 days before my car started messing up, thank god i did. i can still get around

 

im so beyond stumped, exhausted , and frustrated with this dam car. i just know, for a dam fact. its going to end up being some small stupid fkin problem i missed and should have noticed a long time, usually how these things work out.

i just wish, air, or coolant would leak from SOME WHERE, anywhere to give me a place to look at. ive been looking at the same **** for 3 weeks off and on and havent come up with ****. the only reason im guessing it drove today was enough coolant was being pushed through the hole i drilled to make it operate semi how its suppose to. should just sell it right now, for a price someone cant pass up and leave it to them. wont need anything for safety

 

The reason your car doesnt get hot is because you wrecked your stat by drilling a 1/8th inch hole in it. If thermostats require a bleed hole with a check ball then they will have it, if they dont, then they dont require it to bleed. 1/16" is all it would have ever needed to allow air bubbles to pass through to bleed the system. Orientation of the thermostat is the most critical piece of the puzzle when getting the system to bleed correctly after a thermostat change. All thermostats have a specific orientation in which they are to be installed in the housing.

Have you tried swapping thermostats or since you already noted there was a problem with the radiator, have you replaced the radiator?

 

the tstat originally in the car was shot, i replaced it.
i put new one in, and i couldnt get coolant to flow
took it to dealer, they confimed no flow, probably bad tstat, so i bought another, new OEM tstat, tested it, and installed it. here i am