Saab 9-5 Oil Pressure Conundrum

oil
saab
9-5
gauges
airconditioning

#1

I have a 2000 Saab 9-5 2.3t 6 cylinder, with just shy of 80k miles on it. Over the last year, but especially recently, the Oil Pressure gauge has been acting “quirky.” It fluctuates between the midway point, and low, occasionally it will go completely off, and on occasion the check engine light will also turn on. Many times the a/c will then begin to blow warm wet air instead of the steady stream of cold crisp air. I’ve found the car does better if I let the pressure build before turning on the a/c on (though not as a rule), and that the gauge ussually drops if I’m idling for a while.



The car is due, but no overdue for an oil change, and as of posting this the oil level looked good when I checked it. Any thoughts suggestions of magic spells welcome.


#2

First of all, if the CEL has come on there will be codes set. Have them read, post the numbers (only) back for further help.

The oil pressure sending unit may be faulty or perhaps just a loose/dirty electrical connection to it.

Then again you may have a faulty oil pump or even a faulty dash gauge.


#3

It is very unlikely the pressure goes completely to zero and you not eventually hear some noise.

So I’d assume the sender has a problem,Easy to check. Simply remove the sender and attach a real gauge.
the pressure does fall at idle usually, and may fluctuate, depending on the engine wear, shoudl not go to zeo though.


#4

Hi Thanks,

the only code that came up was P0116


#5

So far there has been no noise. Sometimes when the car is restarted the gauge will go back to giving a reading, sometimes not.