There is something going on with my coolant system. I have a 2000 Camaro SS with a stock LS1. When I got home from work the other day, I heard a weird noise coming from under the hood. It sounded like the power steering pump squealing, but I wasn't moving or turning the wheel. Then, I saw smoke coming from under the hood on the passenger side. By the time I got out of the car, the smoke stopped. When I looked under the hood, I noticed that the radiator cap was missing. I quickly found it on top of the water pump lines. I figured the cap popped off and sprayed coolant on the block and headers, which likely caused the smoke. I didn't see anything wrong, so I wiped the coolant off and put the cap back on.

The next morning, I noticed that the defroster wasn't working. When I felt the air, it was cold like the outside air. I kept an eye on the engine temp, which was just reaching normal temp. When the temp. gauge got to 210, I started getting nervous. When it went just over 210, I turned around and headed home. About the time I did that, the temp started going down, and the defroster got warm. Everything seemed fine after that, but now I'm scared to drive it very far. I checked the radiator cap when I got home, and it was still in place.

I'm thinking that the radiator cap isn't venting like it's supposed to, and causing a vacuum in the system. I ordered a new radiator cap yesterday. Is there anything else I could check?

 

I'd check the coolant level very carefully. Sounds like you lost coolant and now have air inside the heater core.

Rick

 

Prior to the cap popping off, when was the last time you removed the cap? Or was it in for any sort of service work where the cap might have been removed? The cap popping off is concerning, unless there's a chance it wasn't installed properly last time. Otherwise there might be some damage to the radiator neck that's not allowing the cap to properly bite, etc. I'd inspect that closely.

Also, as mentioned above, there could now be air in the system. Perhaps a lot of air. Have you checked the coolant level since this all began (both in the radiator and in the expansion tank)?

 

I checked the coolant level a few weeks ago when I drained my catch can. I didn't take the cap off though. I just checked the dip stick. It was full. I checked it again after the cap popped off Thursday. It was still full. The last time it would have been removed, was when I had the headers installed. They had to add a little coolant for that, but that was in February. This all just started Thursday afternoon.

So, my truck batteries were dead yesterday (Saturday) morning, which meant that I had to drive my car into town to get new ones. While I was at NAPA, I replaced the original radiator cap with a cheapo NAPA metal cap. The plastic cap (RC94) from the Chevy dealer won't be in until tomorrow. The car didn't overheat while I was driving around. This morning, I replaced the thermostat. I left the radiator cap off while I poured fluid into the radiator with the car running. A few minutes after the engine reached normal operating temperature, I saw smoke coming up from everywhere. Some was coming from the radiator fill opening (cap removed). Some was coming from the firewall area on the passenger side. I'm assuming that's where the heater core is. It only smoked for about 10 seconds, then went away. Then, I looked down at the radiator, and the fluid was coming up and overflowing out of the radiator. That would explain why the cap popped off. I heard the fans kick on just before this happened.

While all this was going on,. I occasionally checked the temperature gauge, and it never went over 210. It would go down below 210, and then back up to it. I also turned the heater off and on. This didn't seem to make any difference. The air coming from the heater vents never got warm. It was just blowing cold air (it's 65 degrees this morning).

I checked for leaks, and didn't see any. It hasn't lost any fluid since the headers/4L80 swap in Feb. It has a new radiator cap and thermostat. It seems like the water is just not circulating very well. I don't know what else to do.

 

This should not have caused the cap to pop off at all, unless it wasn't properly secured in the first place and/or something is wrong with the radiator neck or cap. Coolant that gets pushed out of the radiator during normal operation just flows to the expansion tank when the cap is securely in place (and that's exactly how the system is supposed to work). If somehow there was too much volume for the expansion tank to hold, then it would get pushed out the top of that tank (as there is MUCH less resistance here than at the actual radiator cap - assuming everything is proper with its connection to the radiator).

So it doesn't sound like you're having any overheating issues now. Perhaps the t-stat and cap change has helped with some of the issues. But obviously something is still wrong if you're not getting any heat. I wonder if there's a blockage in the heater core? This could happen if cooling system maintenance has been poor over the life of the vehicle.

You mentioned that there weren't any leaks, but the smoke coming from the firewall area (assuming it was coolant turning to steam and not a solid substance actually burning) would suggest otherwise. Are you sure the heater hoses don't have a split somewhere, etc.?

 

Only few reasons the heater core doesn't warm. It's clogged, but that doesn't self fix. The system pressure isn't enough for the pump to work correctly or last the pump is bad or failing. Sounds like the water pump is going bad.

 

The car has about 95k miles on it. I didn't think the water pump would go bad that soon. It is old, so I guess it's possible.

It was still overheating. It just wasn't going real high. It was still going above normal temps though.

I'm thinking there's a blockage somewhere. I noticed a gel-like sludge on the dipstick when I checked the fluid level. I'm not sure if that's some kind of stop-leak solution or just nasty old fluid. The car only had about 86k miles when I bought it, so I didn't think about changing the coolant. I'm not sure if it has ever been changed. In any case, I'm not messing with it anymore. I'll just take it to the local Chevy dealer and let them figure it out. I'm not about to dump coolant all over my driveway trying to figure this out.

 

Based on this:

...that's not overheating. That's normal operation for the factory '99+ temp gauge. Anyway, this is mostly a dummy gauge as it will show readings just slightly under or over ~210° for anything in the range of about 185-190° to about 230-235°F. You'd need a scanner to really get a true reading.

Sounds like a coolant flush is definitely in order, at least as a starting point. Overall system condition sounds suspect, so it probably needs this regardless of any other issues.

 

last week, the local Chevy dealer wanted to change the radiator and flush the system. They wanted $1k to get started, and said it might take more to definitively diagnose and fix the problem. I said no thanks, and took my car home.

Today, I took my car to a custom truck/car shop. They installed an air/air power steering cooler, deleted the factory cooler, and flushed the system several times. They said that the coolant looked like Jello coming out. They ran some BK cleaner through it and got it as clean as they could. It doesn't smoke anymore with the heater on, and it doesn't run hot. Parts plus labor was just under $500. I think I found me a shop for my car.

 

UPDATE:

I just drove to Maryland and back this weekend. The engine runs at normal temps, and the heater works when needed. No more smoke in the engine compartment either.

I recommend to everyone with an SS or WS6, to remove the factory power steering cooler immediately. Those things are trouble waiting to happen.

 

Just an FYI. This piece is standard on all LS1 cars by 2002, doesn't have to be an SS or WS6. Can't remember if base 2001 V8s had them or not. But definitely standard by '02.