Oil pressure drops after engine warms up. 318 5.2. Looks like I'll need new main bearings. Anyone on here have them done already, and have any warnings or tips before I dive in? While underneath, I was going to replace the oil pan gasket, and oil pump/screen as well.

 

You may want to hook up a mechanical gauge to verify the dash gauge is correct and if so what the psi is.

 

Hook it up before or after? Because now, when the engine warms up, you can definitely hear metal tapping. I'm 99% sure the bearings are going out.

 

I dunno... I would still check the pressure with mechanical guage... I also remember that some 100 or 110k miles ago, my 5.9 was showing little or no oil pressure at idle and tapping... I think I just went to a higher viscosity oil and it stopped making noise after a bvit (I'm betting the occasional metal tapping noise is a lifter or something else...). You might just try running 15-40 Rotella or a good 20-50 wt oil in it and see how it does. I've had quite a few engines go a Looong ways making some sort of noise...

Juat a thought...

oh, and if you do decide you need new bearings, just save the hassle and buy a complete long block - no point in having new mains and crappy, tired old rod bearings, heads, etc...

 

What's a bvit??

 

lol - sorry, after a bit...

note that it now has 260k miles on the original engine, other than a couple water pumps, tune ups, an ignition switch , couple batteries, etc... (also one scare involving the shut down relay), it's been an extremely reliable vehicle...

oh, and a transmission rebuild 150k miles ago...