Hi Guys,

It seems to be time to replace my oil pump. I am getting low pressure (< 10 psi) at warm idle and what seems to be low (< 20 psi) while cruising. At start up, I am getting 40 psi. This steadily falls as the car warms up. What do you guys think?

If it is in need of replacement, I figure it is best to do the water pump and thermostat at the same time. I considering this oil pump from WS6Store and this water pump along with the correct inlet housing and thermostat.

My car is a 1999 Z28 with 150k miles. It is just my weekend toy and I don't take it to the track. So, I am looking for reliability and not necessarily the ultimate in performance because I am running an all stock motor except for my SLP intake setup (CAI, lid, filter and bellows).

 

10 is ok at idle when warmed up. what wt of oil. could go heavier oil.

 

Changing the oil pump on an engine with over 150k miles nay not result in higher oil pressure. With that much mileage there is a good chance that worn bearings are causing the lower oil pressure. In any event, the pressure you are seeing now is still within specs. Oil pressure normally drops as engine temp increases because oil thins out as temp increases.

 

I am running Penzoil 10W-30 traditional oil.

 

Based on this, do I need to start saving for a rebuild or new engine possibly? What pressure is the tipping point at which I need to to rebuild or replace the motor?

 

try 10w40 and see how it responds. anything less that a pound of pressure per 100 rpms is to low. so 10 lbs at 800 is ok.

 

I'll give that a shot and let you know. Thanks.

 

has the gauge been jumpy lately, pressure switch/sensor may be getting old and unreliable. may want to hook a mechanical gauge to it and see what it says.

 

The gauge has been normal. Where would I connect a mechanical one?

 

My issue seems to be resolved. The oil I took out of the car was a lot thinner than I expected. I know I put 10W-30 in since I still have half a quart. I put in 5.5 quarts of 10W-40 Mobile 1 High Mileage Full Synthetic. It was a little more expensive than I usually pay but I think it will be worth it. My pressure is now at 39 - 40 psi at warm idle and 47 - 50 psi while cruising. This is a huge improvement. Thanks guys!