View Full Version : Low oil pressure...sometimes

09-22-2010, 04:16 PM
Hello everyone,
I have a '90 SC 35th anniversary edition (5-speed, 87,000 original miles) and I'm worring about an oil pressure promlem. First off, the oil level is good and I have installed a new pressure sending unit. For the past few months, all has been well and the oil pressure needle was always steadily on the "M" of NORM. Recently, every once in a while when I first start up the car or I take a hard corner, the needle drops down to the "N" of NORM. If I down shift and hammer the gas while up-shifting almost at red-line, the needle returns to the "M" of NORM. What gives? It's never flucuated like that in the past and I'm worried about starving parts of my engine from it's life blood. Is there some blockage somewhere maybe or is my oil pump going bad? Any assistance would be greatly appreciated. Thank you all....John

09-22-2010, 04:22 PM
The stock gauge is just an on/off switch, install a real mechanical gauge to check what your oil pressure actually is, cold idle, hot idle, and hot cruise.

09-22-2010, 04:26 PM
Soooo, never did that before. Does it install directly where the factory mechanical guage sending unit goes?

09-22-2010, 04:28 PM
Yes it will fit where that sensor installs, or you can use a brass T fitting to install both of them.

09-22-2010, 04:32 PM
That sounds awesome....thanks allot!

09-22-2010, 04:43 PM
I think you have a bad ground causing the fluctuation, The stock gauge is a like metioned a ON/OFF it should not sweep once the engine is running.
If the guage goes dead and the Check gauges lights lights up the its too late anyways.

09-22-2010, 04:47 PM
No warning lights have ever come on....fingers crossed on that one.

09-23-2010, 01:16 PM
well mine used to do that. they are just s crappy gauge.
when i did my timing cover my stock pump had some slop.
I installed a new 95 pump. with a autometer mech gauge.
i get cold 82psi warmed up i get 60-to 75 while driving

using 10w-30 111.000 on the motor

i just grounded out the stock gauge and hooked up the autormeter where the stock sending unit is.

10-13-2010, 01:00 AM
If you have a source for that Oil pump please let me know. If it came with a relief valve and you didn't use it, I would be happy to buy it.

10-13-2010, 03:06 AM
go to the part's store and get the melling high volume oil pump come's with everything ya need for a 100 bucks:D

Torino Cobra
10-13-2010, 03:24 AM
Believe me, if ur hammering you SC and your oil pump aint pumpin,
YOU WILL KNOW! Most likely its that gage, which like they said just show pressure or no pressure,But you can do a search of the forums and you can find some threads about how to make your gage a real one by bypassing the little transister looking thingy ( a resistor) usually behind the instrument cluster, its on the Back of the instrument cluster going to your oil press gage, bypass it , also you have to change the sending unit. And then you will have a real gage,not just on and off like they do in SC' stock. No extra gages to clutter up you interior. Not quite as good as one with numbers, but a lot more matching to the interior!!Its a pretty common trick among us old time SC owners who were used to REAL oil pressure gages!

David Neibert
10-13-2010, 11:22 AM
Probably just a loose wire connection at the sender. Try lightly crimping the sending wire connector for a tighter fit.