How much damage from low oil presure?

[nitro71]

My girlfriends 97 Saturn SC had the low oil presure light blink on and off for a week or so. I had assumed it was the low oil light. Stupid car doesn't have a low oil light. Just a low oil presure light. I'm wondering how much damage it could have done to the engine? Anyone have any insight on this? Thanks!

 

[bisjoe]

Depends on the cause. I sure wouldn't drive it until it's fixed. Intermittent blinking could be a clogging oil filter, oil pump going out, or simply low oil level so that it's sucking air on hills or bumps. Even a bad sending unit!

You could have anything from no damage to scored cylinders or wear on the bearings that will get worse quickly. Hopefully it's minor but do check it out.

 

[nitro71]

It was due to low oil. So that was the cause. Just wondering if there was much damage. Light never stayed on solid.

 

[dogfriend]

Assuming it didn't get hot, probably no major damage. Its not a good thing to do though.

 

[rhauf]

loosing oil pressure for a moment or two probably no damage, loosing oil for more than a few seconds at a time (especially at higher throttle levels) and you can expect damage.

digfriend, what's the theory on the engine damage and getting hot? i'd think by the time friction from lack of oil actually heated the engine, it's be thrashed.

 

[dogfriend]

Friction creates heat, if the engine starts getting hot, you have started damaging surfaces that are normally lubricated. Oil also acts as a coolant, carrying heat away from internal parts.

A friend long ago used to work for one of the automakers as a tech. He said that they actually drained the oil out of a car and ran it around the track just to see what would happen. He said the engine would actually run fine on almost no oil. Your mileage may vary.

 

[rhauf]

i've had two engine loose oil pressure. both spun rod bearings.

the first was my '74 scout (345 v8), i had a oil pressure gauge with a plastic line which broke, i was stranded so i did roadside repair cut the hose and tied it off) tested it, seemed fine.. drove about 2 more miles (on the freeway, towing a car up a grade) and the engine seized. temperature was still right on the N of normal when this happened. (it has a huge radiator though and it was a cool night) it had a couple spun rod bearings and all the bearings were badly scuffed. i rebuilt it.

the second was in my boat (455 olds v8) it lost oil pressure (also due to a leak) and it spun a rod bearing (and scuffed a couple others) i replaced the crank and bearings. the engine was not hot, but it had a whole lake to cool it too.

honestly i think by the time the engine is heating up from friction in the bearings, those bearings will be far beyond destroyed.

 

[nitro71]

Thanks guys, I think she'll start saving money for a new car and we'll hope this one keeps driving for a while. Stupid Saturn, I still can't believe it doesn't have a low oil light.

 

[rhauf]

most cars don't have a low oil light, that's something new that cars have.. explorers are one of the first i know of to have it (first gen explorers) many new cars might.. but other 90's and older cars usually don't.