Can't figure out wtf is going on with this car. It's a 2001 Camaro SS w/50k miles.

The car is getting hot at random. Always when driving though. Ambient temps here in AZ are 105-120 right now.
The first time it got hot, I pulled over and waited about 10 minutes and started it back up and it was already back to 210. I suspected the thermostat. Drove it home and it got warm, over 210, but didn't get too much hotter. I swapped the thermostat, idled for 30 minutes. Never got hot. Drove it again and it got hot. I replaced the rad cap and replaced the thermostat again with a 160 degree. The way it seems to rapidly cool down out of nowhere while idling acted a lot like a sticking thermostat. Idled forever. No problem. Drove it and it got hot. Again, it cools down at idle. I went ahead and took a look at the cooling fans because of the way the radiator is tilted on these cars I thought maybe they require cooling fans to push air through even when driving. They both came on with the ac on, but not with the ac off. Even when the car was running over 130. I hooked up the scan tool which gave me the option to cycle on fan 1 and fan 2&3. (I know there is only 2 fans, but there are 3 relays and those are the options on the scan tool. When I commanded "fan 1" on, the relay would click, but nothing would happen. Swapped the relay, commanded it on with the scan tool and the fans would come on, but at a pretty low speed. When I command the "2&3" fan on they would both come on at a high speed. Not sure if this is normal operation or not but again, it cools down at idle, while stopped. I did recently replace the alternator, and I had to remove the air dam at the bottom, but it is reinstalled. I did notice the last time it got hot, and I let it cool down by idling in my garage that the AC was blowing warm, then cool, then warm. The compressor was operating on and off like normal but it seemed to be shutting off for longer than normal. This is the first time I've had any issues with the AC. I also noticed that the temp is registering at a hotter temp on both of my scan tools than the gauge is reading. The engine is getting hot consistently, but sometimes it cools back down, and sometimes it just runs a little hot. Then sometimes it quickly heats up almost to the red. The randomness makes me think tstat. But I've had 2 news thermostats in it and it acts exactly the same. I don't have any more ideas on this thing. Any input would be appreciated.
Again, only gets hot while driving, even at low rpms, and usually rapidly cools down at idle.

 

I also bleed all air out of the radiator before putting the cap back on. Unless there is a weird procedure for bleeding the air on these, I should be getting all the air out. There are no coolant leaks and it's not losing coolant.

 

my truck was doing the exact same thing around this time last year and it ended up being the waterpump. I could literally ideal the truck all day and it wouldnt run hot but as soon as i started driving it BAM it would get hot. I suspected thermostat at first too so I took the thermostat out and took it for a spin and it still ran hot so that's what led me to the waterpump

 

When is the last time you've pulled the radiator out of the car and thoroughly cleaned it? Sand, dust and debris collects up in the cooling vents causing them to loose the abilty to flow air through and cool the coolant going through the lines in the radiator.

 

Man I thought that only happened with plastic impellers. I'm out of ideas though I'll probably go ahead and swap it. Was the engine in your truck a GM engine with the same style water pump as my Ls1?

 

I haven't pulled it out. I visually inspected it and it looks pretty good. If this was the issue I would imagine it wouldn't cool back down at idle though. 🤔

 

[QUOTE=Ls1ronnie;20510426]I haven't pulled it out. I visually inspected it and it looks pretty good. If this was the issue I would imagine it wouldn't cool back down at idle though. 🤔[/QU

I guess that's the same as saying that I can see circulation in the radiator reservoir so the water pump must be okay.

 

2000 silverado with a 5.3 and a factory water pump. Honestly man I experienced exactly what your speaking of and the water pump 100 percent fixed it. Man I live in Louisiana and it's ridiculous hot here and I can jump in that truck right now and drive it anywhere and it doesn't run hot anymore.

 

Well cool. That's why I posted on here. Hoping for someone with the same/similar experience. The water pump on the 5.3 is the same as the Ls1 so if it happened to yours it could happen to mine. I wonder if it's built up some corrosion inside the impeller or something. Thanks for the tip! We'll give her a go.

 

clogged radiator, internal, or external, could cause issues. you could try a chemical flush. and make sure the rad is fully pressure cleaned on exterior to remove dirt bugs etc.

usually the water pumps will leak a little bit from the weep hole when they go bad. they are designed that way.

 

It sounds like you've already done some thorough troubleshooting, but diagnosing overheating issues can be complex and require a systematic approach. Here are some additional suggestions and things to consider:

Check for coolant leaks: Ensure there are no visible coolant leaks in the system. Even small leaks can lead to overheating, especially in high ambient temperatures. Check the radiator, hoses, water pump, and coolant reservoir for any signs of leakage.

Radiator condition: Make sure the radiator is not clogged or obstructed. Over time, debris and contaminants can build up and reduce the radiator's cooling efficiency. Consider having the radiator professionally cleaned or replaced if needed.

Cooling system pressure test: Perform a cooling system pressure test to check for any internal leaks or pressure loss. A pressure test can help identify if there are any leaks that are not immediately visible.

Water pump functionality: The water pump is responsible for circulating coolant through the engine and radiator. Make sure the water pump is functioning correctly, and there are no issues with its impeller or shaft.

Head gasket test: A failing head gasket can cause overheating. Perform a head gasket test to check for any combustion gases in the cooling system. If the head gasket is compromised, it may require replacement.

Cooling fans: You've already checked the cooling fans, but it's worth verifying that they are operating as expected. Ensure they are coming on at the correct temperatures and running at the appropriate speeds.

Coolant quality and level: Confirm that the coolant mixture is correct and at the proper level. Insufficient coolant or improper mixing can lead to overheating.

Airflow through the radiator: Ensure there are no obstructions to airflow through the radiator, such as leaves or debris caught between the radiator and the condenser.

ECT (Engine Coolant Temperature) sensor: The ECT sensor is responsible for providing the engine temperature information to the ECU and gauge. A malfunctioning ECT sensor may provide inaccurate readings. Consider testing or replacing it if necessary.

Consider professional diagnosis: If you've exhausted your troubleshooting efforts and still can't identify the issue, consider seeking help from a qualified mechanic or a dealership with experience in Camaros. They may have specialized diagnostic tools and expertise to pinpoint the problem accurately.

 

the first thing I did was removed thermostat, then afterwards I did a chemical flushed on the system including the radiator and none of that worked. All roads led to waterpump

 

my waterpump wasn't leaking anything and that was my problem

 

keep us posted on the please

 

Replaced the water pump and I still have the same problem. When I drained the coolant it looks a little cloudy and had some blackish debris in it. I mounted a funnel that seats nicely in the radiator, filled it with coolant, and waited for the air to bleed out. I let it run for a long time, and there was still bubbles coming out so I just kept letting it run. Endless bubbles. I noticed the coolant in the funnel started to appear cloudy as well and some small blackish debris. After idling for a very long time suddenly coolant started blowing out of the radiator as if I had removed the cap from an overheating engine. The engine was not overheating. Based on everything I've seen here I'm suspecting a blown head gasket. I appreciate all the advice, but based on the fact that the engine cools down at idle, and gets hot fast while driving. I believe I've got a bkown head gasket. The first time it got hot it did not get into the red, and never has, but I did notice that my scan tool reads a much higher temp than the gauge is showing at all temps. So it may have gotten hotter than I initially realized when it first overheated. I appreciate all the advice, but I don't see how a clogged radiator would cool the engine at idle, in 120 degree ambient temperatures, but get hot while driving. I'm going to get the blue liquid "block tester" that sniffs out combustion chamber gasses in the cooling system to verify. I'll report back when I do.

 

If you had a blown head gasket coolant gets into the combustion chambers and contaminates the oil. You'd also see white smoke or what looks like steam coming out of the tailpipe. Check it out and let us know.

 

It depends on where the gasket blows. I'll update probably tomorrow. Thanks.

 

I am doubting a BHG. Not very common in the 5.7 I believe.
IF you have one, you will notice: white exhaust fumes, chocolate milk oil, low coolant reservoir, loss of power.

I believe You have a new water pump, and T stsat. You either have a blocked radiator, or air trapped in the system. A compression test would easily figure out the head gasket. Again, not likely on the 5.7 unless you have a **** ton of miles.

if you bleed the coolant system, it needs to be on a heavy inclined driveway. with both AC on, and heater on.

 

Did you jack up the front of the car when you bleed th system? Air in the can be tricky sometimes. Also I sometimes disconnect the hose running to the steam lines and make sure I have a constant flow coming out.

 

You should add coolant to the system slowly to minimize the amount of air you trap inside the system, don't just go pouring it in.