Need4Camaro

iTrader: (1)

99 Z28 from hell.


My old pump was leaking so I replaced with a Duralast from Autozone under warranty. Ive had issues with bleeding my coolant system for a long time but this time its almost impossible.

First my Intake bellow (Slinky thing between the MAF and the Throttle Body) literally shrunk on me after removing it to take the pump off, it literally decreased in diamater and would no longer fit over the Throttle Body, bright idea, microwave the piece so it would expand and fit over the TB, It WORKED, at a cost however, I destroyed my Microwave, literally after it was done the Microwave shutoff and would not come back on.

The coolant level at the radiator is ALWAYS overflowing, its always spilling out the top in a constant poor.
The temp gauge slowly climbs to the 3/4ths mark
The heat is bone cold, meaning nothing is making it to the heater core or if anything is, its dead cold.
When I turn the engine OFF to avoid overheating my radiator turns into a GEYER and SPRAYS coolant EVERYWHERE for up to 30 seconds.

I decided that perhaps because its a pressurized system, since the cap is off, there isnt enough pressure for coolant to pass into the engine so I put the cap ON the radiator before turning it off in hopes that the coolant would preserve itself..Instead, after turning the engine off and waiting a few minutes I touched the radiator. The radiator is BONE COLD. I then OPENED the top thinking there was likely no coolant inside and I was okay to add more, INSTEAD as soon as I twist the cap it EXPLODES off the car like a bullet several feet away into the back yard then me and my ENTIRE CAR gets DOUSED in COLD ANTIFREEZE... THANKFULLY it was cold or I'd be in a hospital right now.

Last time I bled it, I had to drive it until the low coolant gauge came on. I'm not getting that far before it overheats, just a radiator full of highly presurized cold antifreeze.

I KNOW THE THERMOSTAT IS WORKING. I heard it open, I watched bubbles come up from the radiator as soon as it opened...Im not getting even luke warm antifreeze yet its under ALOT of pressure...

I know coolant is making it past the radiator because when I squeeze the upper radiator hose, coolant gets coughed out the radiator.

What on EARTH...

LS6427

iTrader: (2)

I can't believe after 19 years with the LS1 this is still happening....

Look at my Flush write up.......bleed the system as per the Bleed section at the bottom.

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Need4Camaro

iTrader: (1)

Looking for the write up but unable to find, can you link me?

Need4Camaro

iTrader: (1)

Never mind, I found it. I was squeezing only the upper hose, didn't do the lower hose but the thing is, when my T-Stat opens, it just overflows from the fill neck, it doesn't go through the other radiator hose, my radiator just over flows whenever the T-Stat opens and the coolant level at the radiator never goes down.

Chevyguy2001

When i changed my waterpump i had it up on ramps and i refilled the coolant started the car kept filling it up when it was getting low. Never had it spray out at all.

eseibel67

iTrader: (10)

Must be an airlock. Are you doing this with the front right side of the car (rad cap side) as high up as possible? If you can't find an upward grade to park on, use a jack.

LS6427

iTrader: (2)

You need to take the t-stat out, make sure it opens. Throw it in a pot of boiling water.....

If its working.....toss it back in. If you want to make sure you don't get an air pocket on the engine side of the t-stat....disconnect the upp radiator hose at the radiator....put the water hose in the upper radiator hose and start filling the heads/block that way.......when the water starts to run out of the t-stat port, then mount the t-stat back up....while the upper radiator hose is still being filled and water is running out of the t-stat port. This will ensure there is no air pocket on the engine side of the t-stat after its mounted back up.

If there is an air pocket on that side....the t-stat will never open because the heat from the cylinder walls will never make it to the t-stat to open it up.

Last resort...
You can drill a 1/8" hole in the t-stat and make sure that hole is at the 12 o'clock poistion when you install it. Then all the air will push itself out of that hole as coolant starts to flow immediately after engine start-up, and you will have no air pocket. This tiny hole will not affect the cooling system at all....

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wssix99

iTrader: (5)

Several bad things are going on here. It probably isn't just one thing...


Is your cooling system stock? It should bleed itself during the heat/cool cycles as water circulates in and out of the overflow/expansion tank.


This should not happen - at all. What's up with your expansion tank? When you have boil-overs, your expansion tank should overflow. Nothing should come out of the radiator cap. ...unless you have the wrong type of cap on there. If you have the wrong cap, the system may not pressurize properly. That could also lead to some of the other problems you are having.

Our caps are very special. I highly recommend only using GM caps with stock F-Body radiators. They are complex units that release fluid to the expansion tank when the system is over-pressurized and let fluid back in when it develops a vacuum.


+1 This, too.


Yea, that will do it. There are likely metal belts inside the rubber bellows...

Need4Camaro

iTrader: (1)

I think I managed to resolve it, I literally had to fill it with the car OFF, cap the radiator, let the car run for awhile and shut it down, left it overnight, coolant was low in the radiator, filled it again, capped the radiator, let the car run again, left it for a few hours, radiator was low again, topped it off, capped it, let the car run again... heat started working, engine stopped over heating... If I leave the cap off, I lose too much coolant.

Haven't had to jack the car / put it on ramps but I can try that, sounds pretty logical.

Good ideas here. Im pretty confident the T-Stat is still good. I may try the radiator hose trick if I run into more problems

This car is full of bad things, I wouldn't be more surprised to find more

I have an Aluminum slightly larger radiator and I also had to relocate the Throttle Body coolant into the upper radiator hose.

I believe the expansion tank is catching as much as the capacity of the small hose allows for it too, but the coolant seems to be coming out MUCH faster than the expansion tank is able to catch.

If I leave the cap open with the car running, as soon as the T-Stat opens, coolant starts overflowing and pouring out the radiator. Seems as though pumping the hoses doesnt help. I havent tried pulling the throttle body hose near the TB though.

Microwave started working again. If this happens again Im ganna buy a smooth bellow.

wssix99

iTrader: (5)

You can't do this. It's a pressurized system and your radiator is the pressure cap. Once the thermostat opens the coolant will go the path of least resistance.

If you want to take the cap off and look, you can do that when the engine is cold. The fluid level should be at the top. The cap also needs to be on for the siphon to the expansion tank to work properly. The pressure cap regulates that. If you take the cap off when the engine is warm, you'll loose the pressure and siphon.


Here's how it works:

- Start the engine. The engine heats up, coolant flows and expands. Pressure builds. Excess pressure is allowed to escape by the pressure cap and fluid flows to the expansion tank.

- Stop the engine. The engine cools. The coolant contracts and builds up a vacuum. The pressure cap relieves this pressure by allowing coolant from the expansion tank to suck back in to the radiator. (and not crush the radiator from the vacuum)

^ This process will also bleed any air out of the system naturally. The air will gather at the top of the radiator and will be pressed out to the expansion tank first, before any fluid as the system pressurizes and the coolant expands. You can monitor this through the expansion tank levels and by looking in at the radiator when its completely cool. (You don't want to loose that siphon until it has cooled down!)

If you run this through a few cycles and you still have air at the top of the radiator... you have a problem - and not necessarily a bleeding issue. There are a number of instances where gasses can be introduced to the system faster than the normal expansion/contraction heartbeat can bleed them out...

01ssreda4

iTrader: (96)

This is the worst thing ive read all day

Op please read LS6 and WS posts very carefully.

Need4Camaro

iTrader: (1)

In short, I managed to get to get it bled. Squeezing the hoses while it was running didn't work though. Anytime the cap is off while the engine is running, the filler neck is ALWAYS overflowing with coolant, engine will overheat, doesn't matter if I squeeze the hose or not, it just pours out the filler neck even if the level is low as long as the car is running. If I turn the motor off while the radiator cap is not on then the radiator gushes a whole gallon of coolant out the filler neck.

I didn't try disconnecting the throttle body coolant hose.

Instead what I did was filled he neck while the car was OFF (to avoid constantly losing coolant) and then put the radiator cap on, ran the car till it got hot. Radiator itself is still cold. Let the car sit for a few hours (because even though the radiator was cold, its still under too much pressure, last time I took the cap off it gushed coolant everywhere and I lost about a gallon.) Come back and open the radiator and refill it, put the cap back on, run it again.. let it cool down again.. fill radiator up again, repeat process, eventually it stopped overheating, got my heat back, everything works..

wssix99

iTrader: (5)

^ Yep. You'll need to go get a Model T, if you want that old trick to work.


What happened to your overflow tank in this process? Did it go dry? If not and if you had air in the radiator, then you may still either have a problem with your cap or don't have a proper siphon between your radiator and overflow tank. (Either will lead to more problems later.)

LS6427

iTrader: (2)

Well glad you got it....but you must squeeze both the upper and lower radiator hoses to move the bubble past the t-stat.....works every time, first time for me.

Did you do both hoses....it has to work...?

.

1 FMF

iTrader: (1)

i'm still laughing about the microwave failing.

Need4Camaro

iTrader: (1)

Not sure, I should go out and check it. I really need to make a youtube video of what its doing because its not normal. I've bled the coolant on another LS1 and didnt have anywhere near this much trouble. I'd do it but then I'd also have to go out and buy another jug of $15 coolant ...which I cant afford right now lol.

wssix99

iTrader: (5)

Have you checked the level in your expansion tank? What is the level now?

eseibel67

iTrader: (10)

I've filled cooling system from empty on LS1 F-body several times and bleeding air never requires any special intervention. But this trick has worked for me several times on other cars that couldn't get the burp out. Gravity is free and easily accessible so I use it whenever I can.

1 FMF

iTrader: (1)

did you ever get the microwave fixed?

Need4Camaro

iTrader: (1)

I havent checked it yet. I havent driven it in awhile now because after finding the leak literally right after replacing the alternator with my new job beggining only in a few days gave me really cold feet about continuing to use the car as a DD so I literally went out and bought a 5th Gen V6 Camaro for a DD, but I still own the 4th Gen. I will try to check it tonight.

I was very worried I would have to foot the bill to replace it, and its one of those Microwaves thats mounted above the oven too so I couldnt reach the power outlet without removing it. Fortunately it started working again for no explained reason the next day and is continuing to sing her radioactive RF signals away... lesson learned, no more automobile parts in the Microwave