Oil PSI Difference With Different Oil & Filter??

[Yankee John]

After doing lots of work on the top end of my engine, I changed the oil yesterday after 500 miles on the "break in" oil, and noticed quite a difference in my engines oil psi after the change.

I was running the engine immediately after the work with Mobil Delvac 15w-40, ZddPlus addative, and a Fram oil filter, The cold idle psi was 50, hot idle was 13 psi, and psi at 2000 rpm's was 25 psi.

After 500-600 miles now, I am using a Purolator Pure One filter, and 15w-40 Rotella T with ZddPlus additive after I changed the oil yesterday, Now my cold oil psi is about 60, hot idle psi is 20-25, and psi at 2000 rpm is at about 35.

Why would my oil pressure change with just a different filter and brand of oil after the change???

John

 

[A2000RICH]

After doing lots of work on the top end of my engine, I changed the oil yesterday after 500 miles on the "break in" oil, and noticed quite a difference in my engines oil psi after the change.

I was running the engine immediately after the work with Mobil Delvac 15w-40, ZddPlus addative, and a Fram oil filter, The cold idle psi was 50, hot idle was 13 psi, and psi at 2000 rpm's was 25 psi.

After 500-600 miles now, I am using a Purolator Pure One filter, and 15w-40 Rotella T with ZddPlus additive after I changed the oil yesterday, Now my cold oil psi is about 60, hot idle psi is 20-25, and psi at 2000 rpm is at about 35.

Why would my oil pressure change with just a different filter and brand of oil after the change???

John

oil viscosity has a LOT to do with oil pressure----------15-40 is a little thick for optimum use on most TR engines unless you have higher than factory clearances----------don't fall for the mistaken belief that pressure is the only important thing----------higher pressure means that more than likely the oil flow (which cools bearings) is reduced----------i seriously doubt your engine builder put 15-40 in your oil for breakin-----------i usually use 5w-30 or 20 weight for breakin of new engines

 

[charlief1]

Fram filters are some what restrictive. The filter you went to is much better. That's one of the reasons the pressure came up higher.