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Discussion Starter #1
I have an oil pressure light shortly after startup on my mostly stock (C-code) 289. The entire bottom end is stock (to my knowledge) and I've had the car since May and it's been trouble-free.

History: on Monday the car "gets hot" on a 10 mile trip on side roads (never done that before). Temp gets 7/8ths of the way up the gauge before I park it. (normally it sits 1/3-3/5s up the gauge, depending on traffic). After it cools, I add 3 quarts of water (car has no expansion tank) and drive it home uneventfully. (This whole time the cabin heater works well, and the engine doesn't seem unhappy other than being somewhat hot-still idles smoothly, etc)

Tues I check things over before driving to work, fatten up the idle mixture 1/4 turn, add a touch of water (rad is 1/2" below full-see "no expansion bottle" above), check the operation of the T-stat, and generally look things over. Drive to work (12-15 miles) is uneventful, and even the temp stays mid-range. Car is seeping/leaking coolant from the T-stat outlet gasket, but not a major leak. Engine seems hot, but not unreasonably so, and I can't swear that it's not "always that hot" after a drive, since I'm paranoid at this point. (No indication of an oil pressure problem yet.)

Leaving work, I start it up and get an oil light after about 15 seconds. Check the oil, a little low, so I add one quart, retry. Same thing. Engine is idling smoothly and quietly as ever, oil level is slightly below full, but surely not enough to be starving the motor.

Key on: oil and alt lights on.
Start: oil and alt lights off immediately, then oil light returns after 10-15 secs.
If I quickly shut down and restart, the oil light comes back on quickly on the second start. If I let it sit for even 20 seconds, the oil light stays off for 10-15 seconds and then returns. Parked it and grabbed a ride to pick up another car to drive.

Ideas?

I'm going to troubleshoot it as follows, but I welcome other input! (It's in the parking lot at work, and I don't want to get too ghetto-car-repair in the parking lot, as it's a white-collar job full of Moms and Mom-mobiles.)

1. Change oil filter and add 1 qt oil to compensate.
2. Recheck.
3. If I can get hold of one, hook up a mechanical gauge in place of the idiot light sender.
4. Recheck.
5. If that fails, tow it to my garage to pull the pan, check the pickup, the pump, etc.

Any other troubleshooting I can reasonably do in the work parking lot (or even at home)?

Thanks,
--Jim
 

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Go to autozone or pepboys (or similar store) purchase an oil gauge that will provide you the actual PSI reading and hook it up under the hood. Then run the car and report back the PSI at Idle and with gas.

When I had this problem with my car, I had a spun bearing in the motor which causes a lack of oil pressure at idle since the oil hole has some extra space for the oil to pour out of. Or it could just be the pump starting to give up and it will need to be repalced. Or it might just be a bad sender. Too many variables until you get a more accurate reading of the oil pressure.
 

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Kind of hard to say what it is, but I agree with Dodgestang. Get an oil pressure gauge that reads in psi and see what it says. Typically though, if you don't have oil pressure, the hydraulic lifters will start to rattle. If you can't hear them, then you probably have some oil pressure.

Brian
 

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Discussion Starter #4
OK, that's three votes (counting mine) for step 3, the mechanical gauge, so I'll go make the trip at lunch. <fingers crossed>

--Jim
 
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