How do I determine how much engine damage I did?

General Questions
#1

I haven’t been faithfully checking my oil levels in my Aztek and this afternoon the driver infomation area told me my oil level was low. I drove less then 2 miles to a gas station that sold oil keeping my RPM’s under 1500.

At the station when I checked the oil the dipstick was almost dry. I had to put in 2 quarts of oil to bring it back over the top of the dots.

I know running an engine when it is out of oil is bad. The engine has not made any weird noises on the way to the station or after I put the oil in.

#2

You’ll be fine. If the engine didn’t or isn’t making any odd noises (like clacking, or knocking) then you should be OK. You did the right thing by topping off right away but the wrong thing by letting it get that low. Running with low oil for a long time at higher speeds could cause excesive wear which might not be noticeable right away, it could take months for it to show (like a worn cam lobe, or damaged bearing).
I thing you’ll be fine. If you want to toss money at the problem for peace of mind then you could run it to a mechanic and have them do a compression test on the engine and see if all the combustion chambers are within specs and such.
I’m afraid there really isn’t much else that can be done to verify any (non obvious) engine damage.

#3

First question, have you been changing the oil regularly? Just how often do you check the oil?
Without seeing your car and doing some diagnosis, I can’t be 100% certain, but my gut feeling is that if the low oil light just came on and you babied it to the next gas station 2 quarts isn’t going to kill the engine. THIS TIME. Do not make a habit of this. This of course assumes that you change the oil at the correct interval.
However long it has been since you last checked you oil, you might want to cut that period of time in half and check it at that interval.
Also where did the 2 quarts go? Are you driving the Aztek Valdez and leaving oil slicks everywhere you park? Or are you burning it? You might want to find out, as these things rarely fix themselves, and tend to get worse.

#4

Oh, and in reality you were probably only a quart to a quart and 1/2 low.

#5

Rick, in a normally functioning newer car, how many miles would it take a car to naturally go through a quart of oil? Two quarts?

#6

Tough question, it depends on the engine, the age, and usage, and maybe the karma of the driver.
Back in the stone age (1968) We had a customer that had a slant 6 Dodge Dart. We would change his oil and put in 4 quarts. The sump held 4.5 so he drove 1/2 quart down. 3,500 miles later he would be 1 full quart down (burned off the other 1/2 quart) and we would change his oil. Back then that was almost unheard oil mileage.
Nowadays, it is not unusual to not even go though a full quart between service depending on the car and it uses. I had one company car with a 10,000 oil change interval, and it would use just under one quart in 10,000 miles. Most of my cars use about 1 quart every 5,000-7,500 miles.
Part of the problem with coming up with what is normal, is that I could have you drive one of my cars and you might use twice the oil that I do due to your different driving styles, or types of trips you do.
Also you need to pay attention to how the car maker recommends you check the oil. If you do it the wrong way, you might see a 1/2-3/4 of a quart too low of a reading. :eek: Read your manual for the correct method, or if possible park your car on a level surface and leave it there overnight. Check the oil before starting the next AM. This will be the most accurate method short of draining the oil and weighing it. :eek: Yes that is done sometimes to verify oil usage.

#7

  1. I would be surprised if you did any permanent damage to your car - I don’t know if the Aztek has an oil-level sensor or an oil-pressure sensor to trigger the “low oil” dash light, but if the former then you may not even have run the oil pump dry momentarily (which would have caused the dash light to illuminate if it were the second case). I can’t imagine getting any kind of inspection unless you notice unusual operation, or if your oil consumption has been increasing rapidly lately, or if you start hearing funny noises. It is probably a good idea to keep track of usage for the next few fill-ups to get a handle on how much oil you are using - and whether it is going out the tailpipe or leaking onto the pavement.

  2. As far as “normal” oil usage - on a newer car, I would prefer no oil usage at all between changes, and that’s a realistic expectation. However, it’s really nothing more than a nuisance if you go through up to 1 quart every five thousand miles or so, and I believe that no dealer would even entertain warranty work on an engine that had even more consumption - that would be considered within the normal range until it got into the range of a quart maybe every thousand miles. But like Rick said, it can be highly driver dependent. One of our cars has always burned through 1 quart every 3k miles, and it’s just something I’m used to between oil changes (every 5k miles). I had another car with 250k miles (some of those racing) that didn’t use a drop. YMMV :slight_smile:

  3. Oil level is important for a couple of reasons. First, you need sufficient oil to supply the pump so that it doesn’t draw air and cause a drastic reduction in oil pressure, for example to the main journal bearings. Second, oil acts as a thermal sink for parts of the engine - for example, some pistons will receive a flow of oil to help keep them cool. If there isn’t enough oil, then what oil you do have can overheat, reducing it’s ability both to cool and lubricate.

Good luck.

#8

Well I have not been changing it every X miles like most people tell me to do. Instead I wait until the car’s computer tells me to which is what the manual tells me to do so I’m following factory guidelines.

There has been no marks under the car from any leaks so I’m not sure where the oil went but I also have not noticed any smoke comming from the exaust.

I’m starting to notice more things because my extended warranty expired at 100,000 miles and the payments don’t end until October 07