2002 Buick Park Avenue thermostat failure questions

Rich56
Sun, 12 Jul 2020 14:14:58 +0000
Maintenance/Repairs

2002 Buick Park Avenue 3.8 Liters [Not Ultra]

My car overheated because the Thermostat failed.
Can you answer some questions?

When I was young, Thermostats failed in the open position thus the engine would run cold;
which, while not ideal, poses no danger to the engine.
Now Thermostats fail in the closed position so the engine will overheat;
which puts the engine at risk for damage.
Why are Thermostats made to put engines at risk?
Seems like it would increase costs for consumers to repair.

The overheating caused one of two plastic bypass pipes to split.
They have been replaced with aluminum pipes.
What is now the weak point[s]?

The engine was hot at 268°, it would die but would restart.
What made the engine quit?
What allowed the engine to restart?

Note: I did mange to drive to my mechanic: a distance of 3.3 miles?
My mechanic was concerned about the engine but it was OK.
My brother says using Marvel Mystery oil helps protect engine at high heat - any info on this?

10 posts - 8 participants