Intermittent Oil Pressure Light Warning

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Intermittent Oil Pressure Light Warning

June 12, 2012, 10:20:32 PM

My 88 Cougar was in storage for about 5 years, and started occasionally before I got it. After a while the Oil Level warning light and alarm would chime, has the electronic dash, after being started. After you turned the engine off and restarted it a few times, it would eventually go away. My first order of business was chaging the oil, and never had a problem over last summer. After sitting for about 5 months I ran a quick errand with it a couple of days ago - no problem. Last night, when I started it, the alarm chimed again and after turning off and restarting - it went away. The gauge showed one bar, then jumped to 3 bars, then down to one. There was definately enough oil in it when this happened and I didn't hear any loud valves or strange engine noises - was idling normally. I had the dealer check the oil sending unit last year and they tested it and told me it was functioning normally. Last year after the few initial times it happened, I never had a problem. I just changed the oil again, and no issue yet. Is this because it sat for a while? The car has a 5.0 with 31,000 miles on it.

Intermittent Oil Pressure Light Warning

Reply #1 – June 12, 2012, 11:42:22 PM

Which sending unit do you have? There are 2. One that threads directly into the block or another larger one that needs an adapter.

Intermittent Oil Pressure Light Warning

Reply #2 – June 12, 2012, 11:58:55 PM

I really don't know.

Intermittent Oil Pressure Light Warning

Reply #3 – June 13, 2012, 01:47:21 AM

The irv in the dash could be going, or the sensor.

On my 86 I clipped the connector off and applied either power or ground to it and it always read normal after that. From what I remember, its near the oil filter, and a 5 minute job if its the sensor. However, I never found one that read right, and the stupid chime drove me nuts, so I bypassed it.

Intermittent Oil Pressure Light Warning

Reply #4 – June 13, 2012, 09:46:52 AM

Here's what I did: http://www.foxtbirdcougarforums.com/showthread.php?26435-NO-MORE-OIL-CHIME!!!!!one!!!!&highlight=

Intermittent Oil Pressure Light Warning

Reply #5 – June 13, 2012, 09:55:49 AM

Might be a stupid question, but have you done a manual oil pressure test? (Mileage is irrelevant to me when deciding how possible it is that the motor is cooked.) I ask, because I had a similar issue with my HO, and I found the engine to be borked in a bad way. But, (ray of sunshine) now I have a GT40 5.0L and I'm much happier.

Intermittent Oil Pressure Light Warning

Reply #6 – June 13, 2012, 09:58:18 AM

Yup. The lowest the pressure ever read was 16 PSI @ idle on a hot July day after an hours worth of driving.

Intermittent Oil Pressure Light Warning

Reply #7 – June 13, 2012, 01:09:03 PM

@V8Demon
I was actually asking OP...

Intermittent Oil Pressure Light Warning

Reply #8 – June 13, 2012, 04:33:57 PM

My mistake

Intermittent Oil Pressure Light Warning

Reply #9 – June 14, 2012, 10:09:57 PM

No, I've never done a manual test. Might be a dumb question, but how do you do it?

Intermittent Oil Pressure Light Warning

Reply #10 – June 14, 2012, 10:46:14 PM

Go to a parts store an buy a manual gauge. The gauge will come with a length of nylon tube and various adapters that will allow you to install it where the current sending unit is installed. connect the nylon tube to the gauge and the adapter at the engine. String the nylon tube out so you can get the gauge in the car with you so you can read the pressure at idle and under load at various RPMs.

http://www.oreillyauto.com/site/c/detail/HDN0/275/N0528.oap?ck=Search_gauge+-+oil+pressure_-1_641&keyword=gauge+-+oil+pressure

Darren

Intermittent Oil Pressure Light Warning

Reply #11 – June 15, 2012, 07:05:46 AM

You remove the sender and install a mechanical oil pressure gauge in it's place for testing. Then you can know, without the possibility of ANY electrical issues, what the actual oil pressure is. Once you've done that, you'll know if you can trust that you do or don't have a base engine problem. If you've got good oil pressure after a nice long hot drive, then you look into the electrical system, if you don't, then you start thinking about a rebuild/repair scenario that works for what you can do/afford.