: Question on oil pressure???



TXSilverV
02-05-07, 09:47 AM
Need some help!
When you turn the key on but not start the car should you have any pressure reading at all?
One engine is started on idle what should the pressure be at?
I still have major problems with my car. When I turn the engine off it has a hard vibration. Now I have it when I start the engine as well. I noticed when I turn the key on but not start the engine the oil pressure is 12 then drops to 5. The car feels like it is only on 6 cyl! No smoke! just reduced power and sounds like crap.

NoSlackCadillac
02-05-07, 07:29 PM
The oil pump is driven by the crankshaft and mounted to the front of the engine. If I am not mistaken the oil pressure sensor is on the top of the block at the rear. There should be no oil pressure if the engine isn't running.

Do you get a warning message on the Nav display about oil pressure?
I have done an engine swap, so I can tell you what stock idle oil pressure is, but safe to say that you should be over 35# on a cold engine.

Check your wiring harness near the back of the engine. There are several ground wires that connect to the back of the heads. If one of these is broken it can cause problems with your coils, injectors, and PCM. This will definitely cause your car to run poorly, shake, etc. Stay away from wide open throttle. If it is a wiring problem, some of your cylinders maybe running very lean (among a host of other possibilities).

rand49er
02-05-07, 08:26 PM
... There should be no oil pressure if the engine isn't running. ...:yeah:

DILLIGAF
02-05-07, 09:11 PM
Bite the bullet D,take it to 21st.

TXSilverV
02-05-07, 11:28 PM
If I go back to 21st that would mean I would have to tell John Page I'm sorry!
I changed the MAF but did not help. I just took it off and got my money back. Still feels like a V6! Does not sound good. The code was MAF and throttle sensor not calibrated. Not sure what it is now.

Chef
02-05-07, 11:33 PM
Throwing codes?

TXSilverV
02-05-07, 11:38 PM
Yes! Code P0101
PCM has determined that there is a discrepancy between the actual mass air flow input and the calculated mass air flow input.