[Eric]

Nope, original hoses. I did flush the system through the rad hoses and it seemed to flow fine. But even a garden hose could push water through an obstructed system I guess.

I replaced the cylinder head temperature sensor today. You can do it by removing the alternator and basically shoving your hands into the engine valley. You cant see anything but it is the only sensor that screws into the cylinder head in there. The other (knock sensor?) is connected to the block.

Nothing changed after replacing that sensor.

After looking at it a while I decided I had no flow or very little flow through the rad. I decided to pull the upper hose and the thermostat to see if somehow the system is airlocked. No air trapped in there, coolant on both sides of the thermostat. Despite me flushing the system, the coolant I drained out looks like the damn titanic.

I re-assembled the system and left the thermostat out. Fired it up and bled the system. It idles at about 155 F and driving around gets up to 170 F or so. So I now am thinking that despite the thermostat opening and closing when tested somehow it can’t when it is in the vehicle. That doesn’t make any sense, but it is the best I’ve got to go on.

Any other ideas here? I ordered another brand of thermostat (ACDelco) just to try it, only $11 on Amazon Prime.

[Author]

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