I'm thinking you used an aftermarket, Stant or MotoRad thermostat.
These engines are designed for a specific warm up time , you need an AC Delco thermostat 180 degree, not the professional $14.00 one , this one!

This has the part number,

https://www.carid.com/acdelco/gm-ori...n-131-158.html

Oh, and you timing chain is stretching the front guide is broken or almost gone.

 

"Oh, and you timing chain is stretching the front guide is broken or almost gone."

How are you determining the guide is broken or almost gone?

Thanks

 

Noise that rattle sound, I've done over 20 of these Ecotec, it 99% that front guide.

I've seen this many times


I use this type of bolt to avoid that issue

 

Here is a 7 minute video that shows how the temperature escalates. Firemangeorge suggested I test to see if the temperature drops at 180 degrees well it doesn't. It gets to 180 and keeps climbing.

When I turned the car off the fan stayed on and coolant was boiling in the reservoir.

Video:
https://drive.google.com/file/d/0B-c...ew?usp=sharing

 

I'm thinking like oldblue in post #10, if the pressure cap is no good, that allows the coolant to boil. GM P/N 15042975 any shop could probably test it.

Also agree that you should check out the timing chain, if you wait until it breaks, your engine will be a goner.

Thermostats, when they fail, usually fail open. But it is possible that it could stick closed and cause an overheat situation. You could test that by removing the thermostat, putting it in water on the stove with a thermometer in the water, see if or what temp it opens at.

 

I can't see the temp read out in the DIC , what does that show?

 

It shows you need new glasses or a bigger screen!!

Seriously though, temp went steadily up to 230*

 

FYI. I suggested doing that test by taking the car on the road, not by sitting still in park.
On the road there is air flow across the radiator. That's what I was basing the temp readouts on. Back when I thought I had cooling issues, I did many test rides watching the coolant temperature changes. That's how I came up with those readings to watch for. On the road driving.
Sitting still while the car warms up,,,,sorry. Can't give you any info about that. Never tested mine in that manner.

 

I was outside, the glare was hard to read through. I had my glasses on, RJ
I reviewed the video indoor and can see the temp readout , it climbed to 230,
As FMG states it's sitting still , how is it when driven, I'm guessing same issue.

 

With engine is cold, remove the radiator cap, fill the coolant system with water. Completely fill it to the top. Start the engine and watch the water in the locatiuon where the cap has been removed. Look to see if there are any tiny bubbles present. If there are bubbles, it is an indication that the headgasket is failing and will need replaceing. I understand the OP has already had a compression test done and the Psi's are within 10% of eachother, however, a compression test is a limited view of what is happening within the cylinder head.


Has anybody suggested a chemical engine block test? This test will certainaly rule out or definitively confirm a blown head gasket (in regards to exhaust gases entering the coolant system).


Doesn't matter if the vehicle is moving or at a stand still with the engine running. The coolant temperature will still fluctuate with the thermostat opening and closing.


Bad coolant flow???? Faulty water pump???................With engine cold, connect an OBD monitor/scanner onto the DLC port. With the monitor/scanner displaying RealTime Engine Coolant Temperature (ECT) info..........Next, place a tempersture guage into a heater vent (There is a specific tool for this test and can be purchased cheaply at any auto parts store). Next, start the engine and turn on the heater to the maximum heat setting. Look at the scanner and you will see the ECT number rising. This is the coolant temperature in the cylinder head. Look at the temperature guage in the heater vent. This is the temperature of the coolant inside the heater core. The two temperatures should rise at the same rate. The reason for this is because the coolant constantly flows through the heater core regardless if the heater is set to the ON or OFF positions............If the scanner indicates the engine temp is (for example) 150* and the temperature guage in the heater vent indicates the temperature is (for example) 95*.........well, then you will know there is a coolant flow problem (not associated with the engine thermostat)........either a bad heater core or a bad water pump. To rule out a bad (blocked) heater core, simply disconnect both heater core hoses and flow some water thru one end and it will come out the other end. If water doesn't come out the other end, you will know that you have a bad (blocked) heater core (though a bad heater core wouldn't cause an engine to over heat. If water flows thru, you will know that coolant supply to the heater core is the problem (water pump).........However, if both these temps rise at the same rate, you will know that the water pump is not the problem.

Other tests can be performed, but I think I've posted too long of a post as it is. I know some people hate long posts..........Though I generally make long posts. smh.