That is the one I used to do the test. Ran it 'Wide open throttle' WOT and engine was warm, about 5-10 seconds on each cylinder. Still does not tell me around what range it should be for my motor, but it does say that the cylinders should all be within 10% of each other and I got 4 Cylinders very very close so that tells me there is no leaks, but of course after 200k miles on the car the compression isn't going to be what it once was.
I did not add any oil to the cylinders because I wanted a raw reading and some people have said that is like lying to yourself to get a better test score. You'll get a higher psi, but it's not true.

 

You might want to see whether a repeat test gives the same pressures. I believe spec is about 180 PSI.

 

hm, maybe I did it wrong, there was an adapter that looked like a spark plug, I put that in, tightened it down, then hand tightening the hose with the fitting into that. There was really no other way to do it because the plug holes are pretty deep, more then 6" and no way to get the tester out with a wrench since there's a hose connected to it.
So maybe I ran a bad test...

 

The compression tester should have an o-ring on the fitting that goes into the spark plug hole. With that o-ring making the seal, it just needs to be hand tight by twisting the hose.

Test once normally, then add oil to the cylinder and test again. If reading increases substantially you then know that the rings are leaky.

 

I went to another auto parts store and rented a new cylinder pressure test kit. Car ran about 15 minutes or 8 miles prior to that. This time the readings were : 190 - 190 - 187 - 190 , did not test with WOT this time.
Looked good so I drove another 25 miles or so , when coming to a parking lot, heat gauge went up to halfway mark. Drove around, heat went down to 1/4 gauge, normal operating temp. At another point the heat got up to 3/4 so I turned on the heat and drove and it went down again to 1/4. The fan is coming on and one thing I noticed while idling and heat was at 3/4 was bubbles coming up in the resivor tank. Morning mark was between min and max, at 3/4 over heat was over max halfway to the top of tank.
I'm clueless here because my cylinder compression looks good from what I can tell and I also ran a radiator pressure test and it held steady at 16 psi which is the rated pressure for the cap. No visible leaks on the hoses anywhere or on the radiator.
Is it possible the radiator is clogged? I noticed I don't even have to step on the gas for the temp to go down, just be coasting around 40-50 mph downhill and it goes back down to 1/4 temp gauge.

Thank you.

 

Those numbers are much more like it. The temp gauge's normal place is at the halfway mark. Did you properly bleed the coolant system after changing the thermostat? Park it on an uphill incline, or use ramps or jack stands to get the engine angled upward. Turn the climate control up to full heat (but don't turn the heat on), pull off the radiator cap, and start the engine. Let it warm up to operating temperature and let it run until the radiator fan turns on and off twice. That should be enough time to get all the air out of the system.

 

Kits can be purchased to test for exhaust gas in the coolant.

 

Yes, I put it up on a jack when car was cold, took of the rad cap topped it off but I ran the heater while car was running, would that effect the lines? I seem to have a problem with air in the lines because I always get bubbles coming out of the radiator no matter how many times I burp it.

So if I understand right, jack up the car when cold, take off cap, top off coolant, run car with heat open, but no fan pumping out heat, keep topping off coolant and wait for rad fan to kick on at least twice.

 

^Right.

The heater is basically a second radiator, so it would keep the coolant cooler. I don't know much about fluid dynamics, but I assume getting the coolant hotter helps get the air bubbles out. Now, if the car just keeps blowing bubbles after awhile, that might indicate a problem.

 

Opening the heater valve wide open while bleeding is done because air can also get trapped in the heater core. Having the valve open allows coolant flow to move the trapped air out of the heater core.