I bought 2000 LS Blazer that had been sitting 2-3 years. When I start oil pressure is at 20 psi. After warms up it drops to zero at idle. I changed oil and replaced oil sending unit and I am running quart of marvel mystery oil in engine. Using 5W30 Valvoline Max life oil. Was told switch to 10W30 oil.

Was told next oil change to put brake fluid in oil and let run 10 mins then change oil. Never heard of that.

Since it is 4WD how hard is it to change to high volume oil pump and change main and rod bearings with engine still in blazer?.

 

Be very careful running secret sauce in your oil because you can have profound unintended consequences in an older engine.

I would verify the oil pressure with a mechanical gauge and then try 10w30.


George

 

And to answer one of your other questions, you're not getting the oil pan off with the engine still in the truck.