Oil pressure related problem?

[iceman3545]

I have a 97 GST with 78000. I've been noticing my oil pressure is kind of low or at least it seems low. I have a defi 60 BF gauge and at idle with coolant temp around 80C or so and my pressure will be at 25kpa(3.2psi) when I drive for a while. I know that's way below factory spec, but at 5 grand, pressure will be at 600kpa(87psi). I'm debating on whether or not to put a new oil pump on it, but I don't want to do this if I have a different problem in the bottom end. I mean pressure goes up fine, but just at idle pressure seems way to low. Now it could just be my gauge but I highly dout it. I also have a screaching noise from the right side of the motor in the upper valve train it sounds like, but I'm not sure. And it only does it when it's pretty cold outside and the car has been sitting for a couple hours or over night. I haven't had time to check it out properly, but I just want to know if anyone else has experienced these symptoms. I don't know if the two problems i have are related, but any help would be much appreciated.

 

[ddavisaf]

3.5 psi is very very low. You should have a minimum of 10 psi oil pressure at idle.
Did you notice this problem after any recent maintenance?

Have you noticed any new noises coming from the block? A bad front balance shaft will cause extremely low oil pressure readings. You may also have a clogged oil passage such as your turbo feed or return line.

 

[iceman3545]

I haven't done any kind of work on it with the exception of a timing belt and water pump which I did about 12000 miles ago. Even then the pressure was still the same. I mean pressure rises fine, it's just at idle. I haven't heard any nioses coming from the bottom end either, just the noise on the top end only on cold starts. I haven't pulled the valve cover yet to see if the cams are getting starved on the cold starts which may cause the loud screaching noise on cold starts.

 

[Scott_S]

Low pressure could be caused by a few things. The pump doesn't supply any pressure only volume. You get pressure from oil being forced through bearings in your motor so once your bearing wear you will start seeing your oil pressure go down. I have a relatively new motor and while cruising at 75mph my oil pressure gauge is right around 75psi but drops to the factory rated 11psi at idle

 

[TurkF26]

how many miles do you have on your car???

 

[awdtalontsi1992]

Does sound like its very low at idle. Where did you get your pressure signal from? Oil issues are ones that are best nipped in the butt imediately. I would recommend you maybe think about a new oil pump. Have you checked you crank endplay?

 

[Old Mitsu Tech]

I would do a manual test to make sure your gauge and sending unit are right.

I've seen a bunch at 5 psi at idle and are still alive. I would prefer them to be higher, but with the alternative. Most live with it. As long as the pressure comes up when the rpms climb.

Good Luck

 

[iceman3545]

Like I said the car has 78000 on it and the sender for my defi gauge is on the port on the oil filter housing where the old sender for the oil pressure light use to be. I don't know if that's a bad place to plug in for oil pressure, but thats where it is at right now. Once the matco truck comes down to the shop this week I'm going to get a mechanical oil pressure gauge kit and verify the oil pressure at idle to see if my gauges is of or if I might have some wearing bearings. Also one thing I noticed that when the coolant temp is at 70-80C the oil pressure will be at about 100kpa(14psi), but once it starts to get at 90C the oil pressure is at 25kpa-75kpa(3psi- 10psi). So I don't know if a thicker oil will actually help or start thinking about a rebuild???