When do I add oil to the car?
May 13, 2010 10:24 AM   Subscribe

Should I add oil to my car?

The sensor says the oil life has 10% left but it's not a fancy one. It only comes on when there is 10% oil life left. I just got my oil changed 1500 miles ago so I'm thinking the place I got it from last time didn't reset the sensor.

However, I did check the oil using the dipstick in the car... Basically the oil level is only halfway til full.

So like

That's how much oil is in my car.

I'm thinking the sensor in my car isn't smart enough to know that.

Someone told me I have an oil leak once when I got my oil changed, but I have not noticed any oil leaking and no one else besides him has ever said anything and I have gotten it changed since then in a way where they lift up the car and look at it.

However some internet sleuthing has led me to believe that the oil is a closed system and shouldn't be running out at all.

So, should I add oil to my car or is halfway full good enough to drive on and I shouldn't mess with it? I don't really know much about cars. I've read that it's not good to mix brands of oil and I'm not really sure which brand they used the last time I got it changed. Should I just pay the 20 bucks or whatever and get another oil change? Or should I just keep an eye on it and if it gets too low take it in asap?

Is it already too low?

So it probably is leaking. Will this cost a lot, will the problem stay the same or or will it get worse if I don't fix it now?

Thank you for any advice!
posted by tweedle to Travel & Transportation (17 answers total)
So, should I add oil to my car or is halfway full good enough to drive on and I shouldn't mess with it?

Add oil immediately. It's already too low. Don't worry about mixing brands. It's impossible for us to predict how much fixing the leak will cost or if it would get worse; it could be any of a large number of problems. You need to take your car to a mechanic.
posted by mr_roboto at 10:29 AM on May 13, 2010 [1 favorite]

What kind of car are we talking about? Most of the cars that I've seen with "oil change sensors", it really was just based on mileage, not any actual dirtiness of the oil.

The oil level should be at the middle of the "safe" section on your dipstick, not at the top.

---\____*____/------- OK

-*-\________/------- Not OK
posted by nomisxid at 10:30 AM on May 13, 2010

First, make sure your car is running when you check the oil, pull the dipstick, wipe it off, put it back in, seat it firmly, and pull it out. That's where you get your reading.

If it's low, add oil 1/2 quart at a time until it's full. If you're that low (probably 2-2.5 quarts), you could and will seriously damage your engine if you don't keep it full.

You could be burning oil...any smoke when you start up or roll down the road? Any rich, smelly smells?

You could be leaking, it could be as simple as at the filter (they didn't tighten it enough), at the oil pan nut (they didn't tighten it enough), or they could have not filled it all the way.

Are there any oil spots on the ground when you park over night?

If you open your hood and look at the top of the car, any places where two pieces of metal come together (especially valve covers, but you're not expected to know what those look like) or the head gasket (same rules), is there any oil seepage?

The oil life light is PROBABLY only indicating time since last change, so it probably didn't get reset.

However, if you're that low on oil, you need more oil. Take it to a different place.

It would also help us if you gave us the make/model of the car.

Oh, and keep an eye on that oil pressure gauge if you have one. If it's lower than half, you've got really serious issues (not necessarily expensive to fix, just expensive to fix if you don't address them...like...now.)
posted by TomMelee at 10:30 AM on May 13, 2010

It's a 2002 Saturn LS.

No smoke or weird smells. No oil on the ground ever. I didn't check the oil while the car was running. No oil seepage on the inside of the hood but I didn't check if there is any metal coming together.

I don't have an oil pressure gauge.
posted by tweedle at 10:36 AM on May 13, 2010

Oil isn't supposed to be consumed as the car runs: it needs to be changed because it picks up gunk and/or loses its lubricating ability due to high temperatures, but the amount of oil in a (properly running) engine doesn't diminish over time.

Leaving the sensor aside, you need to look at the minimum level, not maxmium: Any level between minimum and maxmimum is nominally OK for the car. You do need to investigate why your oil level is dropping though: You might leave it as is, and take care to top it up every now and then, but forgetting and letting it drop bellow minimum can be catastrophic for your engine.
posted by Dr Dracator at 10:36 AM on May 13, 2010

Oil is cheap.
posted by thejoshu at 10:37 AM on May 13, 2010

Oh and the dipstick, from what I could tell, doesn't even have a safe section or anything. The only word it says is full.
posted by tweedle at 10:37 AM on May 13, 2010

It would help to know the year, make, and model of your car. On mine, the "time to change the oil" light only knows that the oil is getting dark. It doesn't measure how much oil there is in the car. So "low oil" and "time to change the oil" are separate lights on mine.

If you want to know if your car is leaking, next time you park your car, put a big piece of cardboard under the engine (the front half of the car, unless you have something exotic).

If in the morning, you've got fresh oil spots on the cardboard, then it's leaking. Otherwise, it's probably just burning small amounts of oil as you drive.

Oil is not really a closed system. It's as closed as the manufacturer can make it, but it is not perfect. Oil can burn or leak in minute amounts all the time.

If you're only down halfway on the dipstick, that means you've burnt (or leaked) half the car's oil in 1500 miles. It's possible your oil place didn't top off your car, but this would be unusual. Depending on the model and age of the car, being halfway down on the dipstick in 1500 miles this can be normal (on a small car that takes 4 quarts of oil, that would be 1 quart every 750 miles).
posted by zippy at 10:39 AM on May 13, 2010

Some oil gets burned as part of the normal running of your car. Some engines burn more than others. Honda VTEC engines (particularly with oil cooled pistons) are notorius for burning oil, as are audis. This is the reason you should be checking oil every time you get gas, nothing you can do will prolong engine life like keeping the oil changed and topped off when needed. You should add oil to your car. It will be less than a quart (Usually the smallest amount you can buy). However you must buy the same weight of oil as what is in the car. usually there will be a number on the oil filler cap which is located on a valve cover (the top of the engine usually-it will also say add oil here). It will probably say something like 5w-30 or 10-w-40, you must use this number of oil. It has to do with the oil's behaviour across a tempature range and is pretty important. There may be a sticker somewhere on your windshield that also lists what was put in your car last time, or you can check your reciepts from your last change. However if you are unsure, just take it to whereever and get it topped off. BTW changing your own oil is really easy. The hardest part is disposing of the old oil and most auto parts stores will take in oil to get it recycled (they usually make money off of this).

You may or may not also need an oil change, mileage is not really the best single way to measure this. I usally go with a combination of mileage/time since last oil change/and look and smell of oil. The oil should be a honey color and as it gets dirty it slowly turns black. The darker it is the more it needs to be changed. It will also start stinking (this is a skill learned through experience, the only thing I can convey online is smell new, clean oil and smell dirty old oil, and compare to how your oil smells-if it smells strongly burnt-change it). Depending on how I have used my car sometimes I change at 1k miles (usually not much driving for 6 months and only stop and go) to 10k (long highway trips).
posted by bartonlong at 10:40 AM on May 13, 2010

First, make sure your car is running when you check the oil, pull the dipstick, wipe it off, put it back in, seat it firmly, and pull it out. That's where you get your reading.

Whaaaaaaa????? No, no, no. Proper oil levels are taken after the engine has been shut off and has been sitting at least 30 minutes. Preferably longer.
posted by Thorzdad at 11:08 AM on May 13, 2010 [2 favorites]

There's a lot of unnecessarily alarmist advice being tossed around here.

If you're only down halfway on the dipstick, that means you've burnt (or leaked) half the car's oil in 1500 miles.

For any car I've every owned (quite a few) this is simply wrong. You typically have to have a few quarts of oil in the engine before it shows on the dipstick at all.

Oh and the dipstick, from what I could tell, doesn't even have a safe section or anything.

It has a safe section -- you're just not recognizing it. There will be little grooves or bumps or notches on the edge, or something. If the oil is anywhere in that range, you're fine. If it's a little low, just top it off until the level is in the safe range.
posted by jon1270 at 11:11 AM on May 13, 2010

Excuse me, but I was always told the car's oil level is always checked when the engine is off and it has been sitting for at least 30 minutes, as Thorzdad posted. I think perhaps TomMelee is thinking of checking transmission fluid, which is usually done when the car is well warmed and has been running for at least 15 minutes.
posted by Lynsey at 11:12 AM on May 13, 2010

Yea, oops, major mixup in my mind between fluids.

Please edit or delete the part about when to check the oil. My bad. Sorry.
posted by TomMelee at 11:15 AM on May 13, 2010

There is some bad information above. Have you read the owner's manual? Most of your questions should be answered there.

1 - Oil should be checked when the engine is NOT running.

2 - The dipstick has 2 lines: The lower line indicates 1 quart low, the upper line indicates full. Anywhere between the 2 lines is OK. If the level on the dipstick is at the lower line, there is still 3 - 4 quarts of oil in the crankcase (where the oil is stored) , but a quart should be added. Halfway between the lines means 1/2 a quart low, not half full. If no oil shows on the dipstick, the crankcase is VERY LOW and oil should be added immediately.

3 - Go back to the place where you had the oil changed and ask them to answer your questions and show you how check the fluid levels under the hood. Most oil change places will also top off the oil for the first 3,000 miles after you have had the oil changed.

4 - They oil change place probably put a sticker on the upper left corner of the windshield giving the type of oil they used and the odometer reading when the oil should be changed next.

5 - It is not at all unusual for a car to use a bit of oil between oil changes.

6 - The "10% left" light is coming on because someone forgot to reset it at the last oil change. Just make sure to remind them every time you have the oil changed to reset it. It is tied in to the odometer and based on miles driven since it was last reset.

7 - This is simple stuff and well within your capabilities, you just need someone patient and knowledgeable to show you around.

Best of luck and happy motoring!
posted by Daddy-O at 11:20 AM on May 13, 2010 [8 favorites]

I think everything else has been well-covered but when you check your oil make sure the car is level. If you're parked on any significant slope the dipstick may read falsely high or low.
posted by 6550 at 12:00 PM on May 13, 2010

Okay thank you very much for the advice! I took the car to an oil change place and they said I was a bit low on oil and replaced my gasket (maybe?) for me. They said it was kinda leaky.

Now I feel much more informed though, thanks guys!
posted by tweedle at 12:20 PM on May 13, 2010

Saturns as a rule of thumb tend to burn a fair amount of oil. I have two Saturns, they both go through oil, but they also pass emissions testing fine.
posted by Skrubly at 3:47 PM on May 13, 2010

« Older Odd music video   |   Keeping the public in public process Newer »
This thread is closed to new comments.