Alarming Oil Pressure

Campisi · #1 (**permalink**) 02-16-2008, 02:01 AM

When driving along, my oil pressure gauge tends to split the difference between 57 and 114. When I gun it, however, sometimes it spikes up as high as what I imagine is ~110. Is this normal for these cars? If not, could this possibly be due to a faulty oil pressure sending unit (or whatever it's called), and if so how can I test it to see if it's in need of replacement?

**Zunige** · #2 (**permalink**) 02-16-2008, 02:39 AM

No, that is not normal. When the engine is running fast the maximum is supposed to be 65-70 psi, and the minimum 50. (When a fully warmed up engine is idling the pressure drops a lot, but it should not go below 7 psi.) You could check your pressure with a mechanical gauge... There are quite a few threads on this subject, so I would suggest you do an "advanced search" looking "oil pressure" in the thread titles only (otherwise you'll get way too many threads.)

Best regards,

**Roadtrip** · #3 (**permalink**) 02-16-2008, 09:16 AM

My bet is a failing sending unit, but first make sure the wire from the sending unit to the dash gauge is connected correctly and not obviously damaged. If you have an mechanical oil pressure gauge and fitting, you can double check it. If not, it may be just as cheap to just replace the sending unit and see what you get rather than buy a mechanical gauge.

besposito · #4 (**permalink**) 02-17-2008, 08:48 AM

I second the vote on the sending unit. Alfa oil gauges are notoriously problematic.

**John M** · #5 (**permalink**) 02-17-2008, 05:40 PM

Since no one has said it, might also be a sticking relief valve in the oil pump. If this is happening frequently enough to check and catch it with a mechanical gauge, then do so. If its really doing it, rebuild your oil pump.

Best Regards,
John M

Campisi · #6 (**permalink**) 02-20-2008, 07:57 PM

Quote:

Originally Posted by John M

Since no one has said it, might also be a sticking relief valve in the oil pump.

davelgee · #7 (**permalink**) 02-20-2008, 10:36 PM

A short or sender/guage problem is pretty likely IMHO, my OP read between 57/110 (and jumped back and forth) when I first put the motor back in and did the paint.
Turned out to be a wiper apron/rear hood rubber screw (first one to the right of the hood latch) that had invaded the wiring just a tiny bit.

Cheers!
Dave G.

oldschooleuros · #8 (**permalink**) 02-21-2008, 04:41 PM

Get a new send unit and external gauge and see what she says after that.