Oil light on at idle

[Clement]

Another post made me think of this.

1994 Merc Sable, 3.0L, about 118K miles, 2nd tranny.

At idle, only when the engine is warm, the oil light comes on.

I was planning on putting in some 10w-40 to see if this will stop it, figured a thicker oil might pump better when warm.

Anyway, what causes this, can it be easily fixed?

 

[wrangler]

I'm not sure but you may have to change your oil pump. Last i checked for my car, it was about $100 for the part. Labor, no idea... i did it my self.

 

[TR3-2001SE]

Oil light on at idle is not a good thing. It could just be defective. My guess is your engine is dirty inside at this milage. Auto-rx can fix this but have a mechanic check it out to make sure the light is functioning properly. It could be your oil pump also so a good Ford mechanic is needed first.

 

[Curious Kid]

From the generic possibilities that I have heard, some already noted,

-faulty pressure sender/switch. Have the oil pressure checked with a mechanical pressure guage.
-low pressure due to a by-pass valve being stuck open. This valve limits the oil pressure that the filter and bearings actually see.
-clogged/obstricted oil pick-up screen. Perhaps sludge deposits and precipitate debries have collected, and simply needs to be cleaned. And another guess too would be the oil pan.
-since we're on the subject surrounding the pump, perhaps the clearences within the pump itself have become excess, enabling backflow. I don't know the integrety of said pumps on said engines. A shop manual will often give clearance measurements to help make the determination of whether the pump is still serviceable.
- excess bearing clearences will blead-off oil pressure. Check clearences with plasti-guage. Check shop manual for further details.
-perhaps the oil passages have gone by way of plaque to a persons arteries and veins, restricting flow.

I'm not meaning to get anyone worked up, just sharing what I've heard. Start with the oil pressure switch/sender like TR3 was hinting at, then go from there.

Any one who has had a similar problem with a Mercury Sable, we could use your help.

Good luck and keep us posted.

 

[Mike_dup1]

Guy I worked with had a 80s' Mercury V8 that did the same thing. All of sudden one day one the way home form work the oil light came on at 65 mph and never went off. A few miles later it threw a rod.


btw-It had less than 100,000 miles but he got the car used from a old lady who drove only around town to the store, post office, church etc.

 

[Gary Allan]

quote:

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At idle, only when the engine is warm, the oil light comes on.

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If your oil light is on because of too low an oil pressure, you would hear valve clatter. If you don't hear or feel any mechanical symptoms ..the reasonable conclusion is that there is no lack of oil flow. You should experience lifter noise BEFORE the oil light ever comes on (in many cases).

I would replace the sender/sensor in the absense of any apparent (it should be obvious) noise.

Naturally if you do have lifter noise, ..by all means, consult a mechanic and have the pressure checked (which would be obvious with the presense of lifter noise that is reduced or eliminated by raising the idle until the light went out).

Given the age/mileage of the engine, I'd naturally recommend Auto-Rx for all the good things it can do for the engine.

 

[srivett]

My friends Toyota Corolla was doing that too. You could hear it ticking away so he cranked the idle up to about 1800 and the light went out. It lasted about 3 weeks like that but it was consuming huge amounts of fuel right before it died. The replacement engine paid for itself in about a weeks worth of gas savings.

Steve

 

[Bill Plock]

I had an 88 Aerostar with a 3.0L that did the same thing - check engine light (which was tied to the oil pressure sender) would come on at idle when the engine was warm - started at about 60kmiles. I checked the hot idle oil pressure with a manual gauge and it matched the OE factory electric gauge at 20 psi - good. Since I could monitor pressure with the OE gauge, my solution was to pull the bulb from the dash.. I bought the VAN new and changed the oil & filter every 2kmiles... sold it with about 140k miles and it was still running great ...

 

[Mike_dup1]

I guess time with tell, won't it?

Anytime the oil light comes on with engien running, its something to be concerned about. Get it checked out and you will know the answer. All we can do here is tell of experiences and take WAG's.

 

[Clement]

There is no noise coming from the engine, lifter ticking or whatnot. It has done this for the last two to three years, and is probabally the same motor that's in the '88 aerostar mentioned above. The last thing I want to do is spend money on this car. Thanks for the info, I'll see about getting the oil pressure checked.