low oil pressue

briansexsmith · 09-29-2008, 01:40 PM

Info;

1988 mr2 SC
120000 km or 70000miles
almost stock
4500km since last oil change
running redline 10w-40
10 deg C or 55 deg F

I was driving this morning at highway speeds had the cruse control set and the oil pressure dropped down to the big "L" on the gauge I turned the engine as soon as I could and got on the shoulder it was somewhat flat and checked the oil on the stick It looked good as I topped it up after autocrossing the day before.

the next exit was not far so I decided to drive it off the highway it was a bit of a uphill and while driving the pressure came back. I exited the highway and found a place to stop thru all of this the pressure was lower then normal but there.

I decided to add more oil to the engine as the going up hill seemed to help I added 1/2 liter and started it up again and the pressure was normal at idle and went beyond the first mark after a blip of the gas. (so now it is overfilled by 1/2 liter)

i drove away watching the gauge and it never fell again on the trip that was another hour.

at lunch I went out to the now cold car and checked the oil stick it it was overfilled and started the engine and the oil pressure came right up and drove away everything was OK

so what do you think happened? any ideas would be great

thanks in advanced
Brian Sexsmith

328FTW · 10-02-2008, 02:03 AM

Hmmmm, that is funny. Apart from the very slight possiblility of a trapped air bubble not sure, sometimes you can low pressure that if you have rooted mains bearings but it wouldn't generally go back up that easily. One thing I would really recommend checking for is the correct dipstick height, sounds retarded but my car had a dipstick that was waaaay to long and said full at empty and surprise surprise the last owner ran a bearing and I only noticed after I drained the oil and it said full. Also check the oil sender unit wire is not loose, it is up under the distributer on a dome shaped thing and should swivel but not pull off too easy (as in almost falls off). When all else fails install a quality aftermarket gauge that you can trust cause stock gauges can be quite off some of the time.

Hope this helps.

Gunner87 · 10-02-2008, 07:26 PM

Sounds to me like the oil sender is going out or a wire is loose, the worst is an oil pump going out.

09-29-2008, 01:40 PM	#1 (permalink)
briansexsmith No Skills Join Date: Jun 2008 Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	low oil pressue Info; 1988 mr2 SC 120000 km or 70000miles almost stock 4500km since last oil change running redline 10w-40 10 deg C or 55 deg F I was driving this morning at highway speeds had the cruse control set and the oil pressure dropped down to the big "L" on the gauge I turned the engine as soon as I could and got on the shoulder it was somewhat flat and checked the oil on the stick It looked good as I topped it up after autocrossing the day before. the next exit was not far so I decided to drive it off the highway it was a bit of a uphill and while driving the pressure came back. I exited the highway and found a place to stop thru all of this the pressure was lower then normal but there. I decided to add more oil to the engine as the going up hill seemed to help I added 1/2 liter and started it up again and the pressure was normal at idle and went beyond the first mark after a blip of the gas. (so now it is overfilled by 1/2 liter) i drove away watching the gauge and it never fell again on the trip that was another hour. at lunch I went out to the now cold car and checked the oil stick it it was overfilled and started the engine and the oil pressure came right up and drove away everything was OK so what do you think happened? any ideas would be great thanks in advanced Brian Sexsmith

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10-02-2008, 02:03 AM	#2 (permalink)
328FTW You got another WHAT?!? Join Date: Aug 2008 Location: New Zealand Posts: 401 Thanks: 6 Thanked 26 Times in 24 Posts iTrader Rating: (0/0% )	Hmmmm, that is funny. Apart from the very slight possiblility of a trapped air bubble not sure, sometimes you can low pressure that if you have rooted mains bearings but it wouldn't generally go back up that easily. One thing I would really recommend checking for is the correct dipstick height, sounds retarded but my car had a dipstick that was waaaay to long and said full at empty and surprise surprise the last owner ran a bearing and I only noticed after I drained the oil and it said full. Also check the oil sender unit wire is not loose, it is up under the distributer on a dome shaped thing and should swivel but not pull off too easy (as in almost falls off). When all else fails install a quality aftermarket gauge that you can trust cause stock gauges can be quite off some of the time. Hope this helps.

10-02-2008, 07:26 PM	#3 (permalink)
Gunner87 No Skills Join Date: Aug 2008 Location: Alabama Posts: 35 Thanks: 3 Thanked 0 Times in 0 Posts My Google Map iTrader Rating: (0/0% )	Sounds to me like the oil sender is going out or a wire is loose, the worst is an oil pump going out.