93z383

iTrader: (-1)

Car is a 97 z28,

The car takes a long time to heat up, and when it does, it gets about 3/4 up on the temp gauge and runs pretty hot. Never overheats or anything, just runs hot. I tore into it today. Found out there was no thermostat even in the car lol.. can you even do that?

Put in a 160 degree T stat which did nothing to help. Then I drained all the coolant via the plastic plug on the bottom of the radiator, and barely anything came out, maybe 1/8th of a 5 gallon bucket I used, and it billowed steam at high pressure for like 3 minutes straight. Crazy. Checked all the hoses, everything's good or has been replaced, nothing is pinched either. Looks like the owner replaced the water pump too, which is not leaking from the weep hole. When I drained the car, I jacked it up from all angles to try and get it all out. The weird thing is that there is still a bunch of coolant in the reservoir with the dip stick, and draining it all, and running the car won't get it out. I have no idea why that is.

So wtf is going on with this car, and what should I do? I'm wanting to flush the radiator real good, but need to learn how to flush a LT1. Anybody know what's going on with this car?

93z383

iTrader: (-1)

By the way, the car runs perfect, super strong, and has no strange smells or smoke from the exhaust or anything. Just thought I'd throw that in there, I was thinking the head gasket for a second but now I'm 99% sure it's not.

Blind898

iTrader: (1)

If you want to 100% drain the coolant from the block unscrew the 2 knock sensors on both sides of the motor at the bottom of the block, stick a hose in the T-stat housing and let it run for 20mins. As for it running hot mine dos the same thing. After flushing, and putting in a new t-stat it will sit nicely at 195 while driving and all but it takes a good while to warm up. But once its warm and it sits for 3mins the temp will jump to 245 before the fans kick on to drop it.

93z383

iTrader: (-1)

So you think I have a problem or should I not sweat it? Think I should at least pull those knock sensors and flush it?

I just don't want to be kicking myself in the *** later, and I want the car to run colder

What of the no thermostat situation? Do guys actually commonly run w/o a tstat? I mean I guess it would mean coolant would just constantly flow as soon as you start the car, would that keep in running cooler? I've just never seen/heard of that and would like to know. I guess in theory if you ran no tstat in the summer it would be better, right?

LT1FirebirdSLP

iTrader: (2)

Pull the knock sensors. Flush the motor.

As for the thermostat. You really should have one. It helps regulate the temperature of the motor. Coolant in the radiator gets a chance to cool down while coolant in the heads and block is doing its job absorbing heat. Once a certain temp is reached, the thermostat opens and the two figuratively swap places (not as simple as that) then the cool coolant from the rad starts absorbing heat, and the hot coolant from the block goes to the rad and begins dissipating heat into the air. Without a thermostat you kinda just get a constant flow of coolant from rad to pump to block and so on and so forth with out ever really giving the coolant a chance to either absorb heat or cool down.

Also, make sure your fans are working and that you are using your air deflector on the bottom of the car to direct airflow up and through the rad. Without it, air will continue to flow under the car with out being pushed up and into the rad. And that means the rad can't dissipate heat as efficiently.

93z383

iTrader: (-1)

Thank you for answering the tstat question I will keep the 160 in there for sure, it should do great anyway. I had to pull it from my 383 car but I don't drive it much so I can order one, just needed one NOW lol.

So yeah I'll flush the system and report back. Can someone tell me if this is correct just to be sure?

Drain the radiator by pulling the plastic plug & removing radiator cap
Replace plug
Pull knock sensor x2
Run the hose down into the top of the radiator & flush, water should come out KS holes?

Should I do this a few times, like put the KS' back in, fill the engine with water, run it for a few minutes, pull the KS and flush it again?

And when it comes time to fill the car back up all the way, you do it while the car is running, loosen the bleeder screw on the Tstat, and fill until all the air is out, coolant starts flowing from the bleeder, and the level is proper?

Blind898

iTrader: (1)

"Run the hose down into the top of the radiator & flush, water should come out KS holes?"

Pull the knock sensor and run the hose down the T-stat housing. Running it in the radiator can work but doing it threw the T-stat housing's better.

http://www.youtube.com/watch?v=njLXL...ure=plpp_video

Closest video you will get that will give you an idea.

93z383

iTrader: (-1)

lol I was just watching that video

Thanks for the quick answers I really appreciate it, you have no idea lol

I'll give her a few flushes and report back.

LT1FirebirdSLP

iTrader: (2)

Couple notes here.

1. Optispark rules all. Be very weary with liquids going near it. That said, prestone makes a great flush kit if you don't mind cutting into the heater hose. Here is the kit. It makes for a very easy way to flush, just plumb in the kit and hook up a garden hose. Run the motor while flushing.

2. You may only have one KS. I have a 94 and there is only one on the passenger side. There is just a plug on the driver side. When I flushed I just pulled the plug on the driver's side. However, the choice is really yours.

Water will go in the kit via heater hose, out the hole in the block. Wait till it runs clear. Then turn off the car, drain everything (rad and block), refill with 50/50 and bleed as necessary (use lots of rags, protect the opti)

To refill I start with an empty system, add fluid till it doesn't go down anymore, start car, add more fluid, open bleeders, add fluid, close bleeder, add fluid, cap the rad, then drive it a little and let it cool down. Check level and add fluid in rad if necessary, this should get you close. Might take you a few drive cycles to get 100% but I've never had any issues with this method.

Also raising the front of the car will move trapped air to the front of the car (ie into the rad and out of the heads)

93z383

iTrader: (-1)

Awesome, I'll follow that then. Yeah I just went under the car, saw only 1 KS on the drivers side, and ran back in here, so you answered my question before I even had to look it up

1 more thing, how does the connector on the KS come off? I'll just look it up but if anyone wants to answer quick that works too Just don't want to break it.

LT1FirebirdSLP

iTrader: (2)

Pretty sure it's pinch and pull

93z383

iTrader: (-1)

Ok this is bizzare dude....

Flushed it all out, put KS back in, reconnected everything back up. Poured coolant in with the bleeder screw open and the car running several times for a few minutes until it warmed up and started circulating..

Once it was warm, coolant started overflowing back up out of the radiator and the plastic resevoir, and EXTREMELY high pressure steam is spraying out of the bleeder screw on the tstat. It was so hard it blew my big work light off the engine, and continued like that for at LEAST 10 minutes straight, it's in fact still going, I just came inside for a quick smoke and to post this.

Wtf is going on, something has to be wrong here. Clogged radiator? What the hell is this?

SS RRR

iTrader: (2)

Are you sure the steam pipe return and reservoir hoses are not mixed up? The steam pipe return goes on the port below the reservoir port.

97Z28SS

iTrader: (5)

Something is pressurizing the cooling system and in my expirence it usually means a blown head gasket.

Blind898

iTrader: (1)

This is the same thing my car dos too, the system seems to get under high pressure so theres no way to have the cap off before it starts blasting out all over. Even with the cap off while the cars cold then turning it on to warm up. Once it starts getting hot it turns into a boiling mess. My buddys 95 formula doesn't do this at all and its the same engine. As for the head gasket cmt at least for me im no lossing any coolant or oil and they arnt mixing.

What kind of work has been done to your motor 93z383? Before i got mine i was told the engine had been rebuilt with some minor work to it but no one could tell me what was done.

Could an incorrect part or something put on wrong cause the cooling system to go crazy?

SS RRR

iTrader: (2)

Maybe? IMO either that or your system contains a massive amount of air.

Blind898

iTrader: (1)

On this diagram should hose #4 uptop have a constant flow into the radiator with the t-stat out? or is that hose 13/14 that dos that? I know on a 95-97 lt1 its abit different. with my friends 95 firebird there was a constant flow from a hose under the cap when we took the t-stat out when flushing it.

93z383

iTrader: (-1)

Well the car in question is a 97 z28 M6, my daily driver, but the 93 I built myself, everything but the internals. I know a decent amount on these cars but somehow there's always a surprise waiting for me no matter how many times I've done something.

So I seem to have gotten all the air out, and the car is running a bit cooler. Now it stays around the mid line once it's hot. Bad headgasket is definitely out of the picture, no oil/coolant loss and the coolant that came out was bright green. I'll have to check on the hoses and make sure they're routed right.

The crazy pressure thing happens only when the car is off.. I guess it's just the system depressurizing but I figured if it was fully bled coolant would come out at some point and not just nothing but vast amounts of air.

LT1FirebirdSLP

iTrader: (2)

As soon as the coolant system stops cycling, its going to heat up because you have coolant absorbing heat from the motor but not going anywhere because the car is not running. So there will be a period of time after shut down where the system will be under greater pressure.

The car sounds like it is running a bit cooler which is good. Midline is about where you wanna be.

I would say in the future, once you have the car at operating temperature, do not open rad cap or crack any of the bleeder until the car is cool to the touch. If you are going to bleed, do it while the car is running.

93z383

iTrader: (-1)

So there's still some pretty strange **** going on... I checked all the radiator and heater hoses and they are all routed correctly and in good shape. Pulled the passenger knock sensor and flushed the coolant, put in a 160* thermostat after seeing there wasn't one at all in the car. It's slightly better, but the same as before. When cruising the car stays pretty cool, around mid line, very cool on the freeway. After driving a while or sitting still, it's still getting about 3/4 up and staying there even when the fans kick on until I get moving again.

When I shut the car off and it sits for maybe 5 minutes. I hear a lot of loud bubbling coming from under the radiator cap and the thermostat housing. No idea if that has anything to do with it..

I'm lost.. all I know is everything appears to be functioning properly - water pump, fans, hoses, radiator - but the car is hot. Not even just on the gauge, but the car is so hot when I was working on it today everything in the engine bay was so hot it burned me a bunch of times even after the car was off for an hour. It's also raising my IAT temps and making the MAF, TB, everything super hot which is bad for everything.

WTF...

I mean is it possible I just have a water pump that's working very poorly, maybe a cheap brand or something, or ditto with the radiator? It just doesn't make sense because I've tested it all, taken hoses off with the car running and the waterpump seems to be pumping coolant fine, and coolant is passing fine through the radiator as well. All I have to compare to is my 383 LT1 car with a Meziere HD waterpump. That thing never see's anything above 160 and even when running everything in the engine bay is cool to the touch. This just doesn't seem right.