Low oil pressure, tried numerous things with no improvement

[tsidrift1]

So, My buddy has a 90 fwd talon. Its got low oil pressure. Im talking about 2-5psi at cold startup. When he gets to driving it goes up some, but not what I was used to seeing on my old 1g. I would have around 90 on a cold start, falling to 22psi or so at warm idle. Over 100psi at wot. He is seeing around 60psi at WOT. The car has had three different motors in it. The first was original, junk I believe. So it was taken out an replaced with a stock rebuilt shortblock. Well this block had the low oil pressure as well. Last weekend he bought my shortblock from a gvr4 I had purchased. 1500 miles on it weiseco, scat build, bse kit done properly. Still low pressure. He is running an autometer cobalt gauge, mechanical, which came straight out of my old 1g and was giving me the number I had stated previously.

Here is what we have replaced
Motor
external oil cooler
oil filter housing
oil filter
oil pressure gauge line


I just dont know what else to look for??

Ideas??

Anthony

 

[doubleclutch99]

Have you checked for kinks in the line ? also where are you tapping the oil line in ? have you ported the OFH pressure bypass ?

 

[snowborder714]

Have you tried running a different weight oil?

 

[99gst_racer]

Did that gauge ever read higher for him?

With that list of stuff that you guys have already replaced, I'd really be leaning towoard a defective gauge.

 

[tsidrift1]

The gauge came straight out of my old 1g that I parted out. It was reading 22psi for me at idle. I dont think he has tried to change oil weight. I checked the oil pressure line yesterday and there was no kinks. He has it tapped into the oil filter housing right where the dummy light sensor normally goes.

 

[onefast2gdsm]

The gauge came straight out of my old 1g that I parted out. It was reading 22psi for me at idle. I dont think he has tried to change oil weight. I checked the oil pressure line yesterday and there was no kinks. He has it tapped into the oil filter housing right where the dummy light sensor normally goes.

Still, you should try and use another gauge just to make sure. My autometer broke, kept getting frozen at certain points and once you revved it hard or turned the car off the needle will return to zero. It was an autometer sport comp mechanical gauge. They do break. Change it and see if there's a difference

 

[99gst_racer]

Honestly, I'd try a different gauge. Even if only to rule it out as a problem. 2-5 PSI just isn't possible on a cold start-up with a good running engine - especially after checking all of the components that you've checked.

My money is on a defective gauge. Instrumentation fails more often than most people think.

 

[tsidrift1]

True, I guess I could tell him to get another gauge and see if that fixes it.

 

[Spoolin4Ever]

Yeah and what's inexpensive and easy is a oil pressure tester:
Engine Oil Pressure Tester

And BTW 2 things:

1. I agree it's probably the gauge.

2. Does the oil light ever come on? It comes on when pressure is at 3 lbs i heard

 

[tsidrift1]

Dummy light went bad a year or so ago, since then, then mechanical oil pressure gauge line has been in its spot.

 

[Spoolin4Ever]

Dummy light went bad a year or so ago, since then, then mechanical oil pressure gauge line has been in its spot.

It has both stock and aftermarket opg's?

 

[ed1380]

check the oil pressure at the OFH with a mechanical gauge. if pressure is still low, then main bearings are going bye bye

 

[Spoolin4Ever]

Does it have balance shafts?

What about the oil relief mod? I forgot the exact name but it'd down on the filter housing a believe..the relief port.

Although I kind of suspect that gauge since it did it on the other engines as well in his car.

Is the stock gauge also connected?

 

[99gst_racer]

check the oil pressure at the OFH with a mechanical gauge. if pressure is still low, then main bearings are going bye bye

His mechanical gauge is plumbed to the OFH. And the gauge has read low oil pressure on 3 different engines.

It's the gauge...

Does it have balance shafts?

Post #1:

Last weekend he bought my shortblock from a gvr4 I had purchased. 1500 miles on it weiseco, scat build, bse kit done properly. Still low pressure.

Is the stock gauge also connected?

Post #10:

Dummy light went bad a year or so ago, since then, then mechanical oil pressure gauge line has been in its spot.

 

[ed1380]

His mechanical gauge is plumbed to the OFH. And the gauge has read low oil pressure on 3 different engines.

I meant get a oil pressure tester to make sure his gauge isn't wrong

 

[SrKegler]

Agree on another pressure guage just to check. I notice he has the BSE done. Wonder if its possible the block off bearing is crushed or not sealing good resulting in lower pressure.

 

[Devilman]

Are you using the same oil pump on all three engines?

 

[tsidrift1]

No, all engines have had different front case/oil pumps on them. He is heading out of town this weekend, but hopefully we can get another gauge to check if its the gauge or not.

Im not a genius with these cars, but i know quite a bit taking my old 1g apart and building it multiple times to know the in and outs. This has just got me stumped.

If it is the gauge, I will be shocked. I pulled it out of my talon in October of 2010 when I parted it out. Was working fine when I pulled it. He hooked it up maybe 3 weeks later and been reading low pressure ever since.

 

[Auto RS T]

I would want to verify the oil pressure with another gauge.

 

[VisionPaintball]

Did you touch the oil pickup at all?

 

[tsidrift1]

ok, we just did a few more tests. we changed out the oil pressure gauge, nothing. We changed out the oil pressure hose, nothing. We also took the new oil pressure gauge, and put it directly to the oil filter housing, same results.

So then we changed the oil feed line from the oil filter housing to the head, same results. We got a 10psi cold startup pressure reading.

We looked at the line for the oil pressure gauge. The car doesnt even push the oil all the way through the clear tubing up to the gauge. As we rev it, it pushes the oil up through the tube, but it never makes it to the actual gauge. Seems as though he has just had a stroke of bad luck with three different motors with low oil pressure problems???

 

[hairybeanbag]

I was reading through the newer SA Design 4g63t how to build book from amazon, there's a pretty good read on how worn crank bearings can cause low oil pressure. Robert Bowen explains how oil can escape from the journal bearings faster (when worn) then the oil pump can feed them. Might be worth a look?

 

[99gst_racer]

We looked at the line for the oil pressure gauge. The car doesnt even push the oil all the way through the clear tubing up to the gauge. As we rev it, it pushes the oil up through the tube, but it never makes it to the actual gauge. Seems as though he has just had a stroke of bad luck with three different motors with low oil pressure problems???

Try bleeding that air from the line.

 

[97gst_spyder]

Or slap an electric gauge in there for a hot minute to test....

 

[milby43]

I don't want to hi-jack. But I'm having a problem a little similar.

At idle my stock oil pressure gauge will sit at the lowest notch maybe a needle width higher. At 3000rpm, cruising, Ill see the needle close to the mid way mark. As far as I read in Haynes, at 3000rpm it should be at the notch on the gauge. Anywhere below is idle speeds, but almost bottom of the gauge at idle? I don't think i ever saw the gauge max out at WOT.

As i drive around, my oil pressure will raise, but never to the middle notch on the gauge. And I shift at 3000rpm. Now driving around, I don't put a lot of load on the car. So I can see it maybe not responding fast and raising exactly with the rpms. but our pumps increase pressure with rpm.

So should i worry about my oil pressure?
Im going to be hooking an external oil press. check gauge to the car soon at school.
Any help would be greatly appreciated

Andrew