Oil changing questions I should have known by now but don't

[wjm52358]

I've done probably a dozen oil changes now across 4 or 5 different vehicles, and there are some questions about things I could be doing better.

1. How do you guys figure out how much oil your car is burning? The only time I've taken the time to estimate it, I've slowly added oil right before an oil change, run the the engine for a second, waited 10 minutes, and repeated this process until I reach the top of the dipstick. This is time consuming and wastes oil, but I've never seen a dipstick that has indicators on it for how low you actually are.

2. When you check the dipstick, you wipe it off and stick it back in. Some dipsticks are harder to read than others. I've taken to giving it a 360 degree rotation once seated (especially the cable ones). I could see that being a problem if the dipstick enters the surface at a low angle, but then you would have inconsistent results depending on the rotation of the dipstick.

3. When filling the car with oil, is there an easier way to hit the right target than slowly filling, checking, filling, and checking? It seems like the mfg recommended oil volume can vary based on how much you spill when you prefill the filter, how long it drained for, etc. And then I always try to run the engine once I'm close to perfect, to get the pump and filter saturated again, so this whole process can take a while.

4. Does anyone ever use a syringe and tube to suck oil out of the top in case you overfill it, ala Jiffy Lube? I'm trying to nail down my car's oil consumption problem, and filling it accurately to the maximum line is important for avoiding a dry engine and for troubleshooting.

 

[Ride_Red]

1. You just get a sense of how much oil it takes to top off your car. For example, if the oil is halfway between min and max. Take a mental note of how much oil it takes to top it off to the full mark. Then, when it's time to change the oil, check it again and just make an estimate of the amount it is low. That's all people are really doing here.

Many engines take about 1 qt to fill up from the low mark to the full mark. Some a little more, Some a little less. It's easy to estimate how low it is once you figure out your engine.

On my Chrysler minivan, I knew I had to check the oil every 2 weeks and add oil. I just mentally added up all the times I poured in a half quart and figured out that it burned about 1/2 quart every 1000 miles (and twice that when towing). I never topped up right before an oil change to get an exact amount.

2. Pull the dipstick. Wipe it. Wait a few minutes for oil to drain down out of the dipstick tube before inserting the dipstick. Pull the dipstick and read the level. My 4Runner was notorious for oil in the dipstick tube. My Honda CRV didn't have a problem. It just depends on the car. YMMV

3. I pour from a fresh 5qt jug. Pour in close to what the owners manual calls for. I then start the car to fill the oil filter and back it off the ramps. Shut it off and wait a few minutes before checking the level. Then I top up to the full mark. Once that is done, take a note of how much of that new 5qt jug you used. The next time, just pour that amount in straight away and you're going to be right near the full mark on the first pour. The little quart and liter marks on the side of the jug are accurate enough to figure the amount. Remember, close to the full mark is just fine. You don't have to be exactly on the full line.

4. Using the methods noted above, I haven't overfilled an engine in a long, long time. I don't own a MightyVac, so draining out extra oil would be a messy operation for me. If I needed to do it, I would probably clean out my oil pan, then crack the oil filter loose to drain some oil out. Start the car to refill the oil passageways before checking the oil level. Then use the oil in the clean oil pan to top up to full.

 

[fantastic]

I've done probably a dozen oil changes now across 4 or 5 different vehicles, and there are some questions about things I could be doing better.

1. How do you guys figure out how much oil your car is burning? The only time I've taken the time to estimate it, I've slowly added oil right before an oil change, run the the engine for a second, waited 10 minutes, and repeated this process until I reach the top of the dipstick. This is time consuming and wastes oil, but I've never seen a dipstick that has indicators on it for how low you actually are.

No point in adding oil right before an oil change. Yes, you're wasting oil.

2. When you check the dipstick, you wipe it off and stick it back in. Some dipsticks are harder to read than others. I've taken to giving it a 360 degree rotation once seated (especially the cable ones). I could see that being a problem if the dipstick enters the surface at a low angle, but then you would have inconsistent results depending on the rotation of the dipstick.

Wipe it off & stick it back in then test. My manual states to run the car & then wait 10-15 minutes to check the level after the second dip. Check your manual. Hot oil expands & they may want you to test level with oil warm at least. Always make sure you're on decently level ground or you'll just end up overfilling or underfilling.

3. When filling the car with oil, is there an easier way to hit the right target than slowly filling, checking, filling, and checking? It seems like the mfg recommended oil volume can vary based on how much you spill when you prefill the filter, how long it drained for, etc. And then I always try to run the engine once I'm close to perfect, to get the pump and filter saturated again, so this whole process can take a while.

Not really, that is the best way. Taking your time is tried & true. Oil takes some time to reach the sump. Not familiar with those other methods you mentioned & would never put in what came out. Instead get refer to the manual & go from there.

4. Does anyone ever use a syringe and tube to suck oil out of the top in case you overfill it, ala Jiffy Lube? I'm trying to nail down my car's oil consumption problem, and filling it accurately to the maximum line is important for avoiding a dry engine and for troubleshooting.

Just try to figure out how much the min to maximum dipstick lines represent in oil volume. Many are around 1 quart give or take. Using a tool like you suggest would be a good way to remove it but if you have dirty oil in the catch can you can't ideally reuse it. If you get a fumoto valve or similar you could put a clean pan under & drain slightly to reuse the oil when that time comes.

Stick with it & you'll figure it all out.

 

[Kalle.J]

Just check it in the morning before start up, add X amount and see where it ends up?? This is not hard.

 

[oil pan 4]

1 I fill the oil to the full mark and check it on 500 or a thousand miles.
2 try not to over think it. Check oil on a cold engine after it's been sitting say overnight.
3 you should be able to hit the low mark on the dipstick first try by reading the manual and putting most of that amount of oil in.
4 the easiest fastest way to reduce oil level a little bit is pull the oil filter off and dump it and put it back on.

 

[supton]

I've had a couple of cars whose manual indicated if the low level was a quart or 0.5 quart. Not often though.

I check either first thing in the morning, or, if I drive to the work in the morning and then take a walk at lunch time, check then. 4 hours is more than enough to drain down. Thing is, I don't even need a rag to clean off the dipstick, just pull it out, that's the level. Easy-peasy.

 

[ATex7239]

Anytime I’ve had an oil consumer or leaker I’ve added an extra half quart during the oil change and checked the oil cold every 1000 miles. That will give you a good idea since the new oil was put in at ambient and you are checking it at ambient. And unless the oil the really dropping fast it gives plenty of room without over filling too much to begin with. Half a quart over or under is not enough to cause any harm. You don’t have to be exact. Consistency is more important. My 2 cents.

 

[PandaBear]

I always check the dip stick only after parking the car for a night. I don't trust the amount of time it takes for oil to go to the bottom of the engine after running it, topping off, or changing oil until parking overnight. If I top off I only trust the reading the morning after, not 10 mins.

After a few times I sort of remember how much oil it take to get to the middle or top of the acceptable range. I don't care too much about precision because when your car is turning, stopping, starting, engine running at high rpm, etc, the oil fluctuate and that's why oil pan has a volume (it is not just for OCI, but to keep the oil pickup submerged at all condition).

When I drain my oil at oil change I put them back into 1 gal milk jug to recycle. I know around how much is back out of the pan vs how much is added, that's how much it is burnt in one OCI. If I have to top off I would aim to add that over the OCI gradually (say to top off 1 qt over 3 months, I would add 1/2 qt after 1 month and then another 1/2 qt after 2 months, so when I am doing oil change it would be around where I want). It is not rocket science and even if it is wrong it won't be too bad, just whatever I'm comfortable with. I am comfortable with the oil drain out being about 1 qt below what I fill in, you may not, it is up to you.

 

[50yr Street Mech]

I don't add oil before an oil change. That' a complete waste of new oil. I don't pre-fill the filter either. I warm up the car to operating temp and dump the oil and filter, ( be careful, it's hot ). The car is sitting on a slight angle toward the oil plug hole. Take off the filter 1st. Then go for the engine plug. Let it all drain out till nothing left but a drip every minute. Re-install plug withe new crush washer. Smear some oil on the filter gasket. Tighten by hand, then a 1/4 turn by filter wrench. Clean up and dump the old oil & filter. Put the vehicle on LEVEL ground. Add new oil and overfill by 1/4" on the stick to accomodate for the empty filter. Crank engine without starting it until oil light goes out. Check level. Add a little bit if needed. Run the engine to operating temp and go have a cup of coffee. Come back when engine is cool, re-check dip stick. Add a little bit more oil if needed. Slap a sticker on windshield and re-set oil life. If the engine is a burner, I'll monitor level every 2 days on cold engine. Add some oil if needed. You get the hang of it after awhile. If you drive futhur than usual, you will probably have to add more oil. ALWAYS keep some oil and a rag in the trunk just in case. That's all I got

 

[B6_Dolphin]

If you use an oil extractor, where the oil is dumped into a graduated cylinder, it's fairly easy to see how much oil has been removed from the crankcase.

 

[Vil_Riker]

I think OP is taking this way too seriously.

Drain the oil, add the recommended capacity less half a quart. Let it drain to the oil pan for 10 minutes, check the dipstick. If it's within the recommended level, start the engine and check for leaks. Run for a few minutes and turn off the engine.

The next morning, check the level and top up as necessary.

 

[50yr Street Mech]

WJM, Checking the level on the dipstick can drive you insane. Yes, you get different readings on either side of the stick, it's hard to see level because oil is clean. It's even worse on a transmission stick. You're best bet is this. If the engine takes 4.5 qts with filter, just add 4.5 qts and start the engine. Once the oil has settled down the next morning, the dipstick will read the same on both sides. Add more oil if needed. Practice, Practice, Practice, makes perfect.

 

[eljefino]

Some cars get oil up inside the dipstick tube, particularly if you've checked them a couple of times, which then smears on the stick and gives an artificially high reading. I've had success doing one early morning pull and trusting it-- not wiping it, reinserting, and reading.

Of course every car is different.

As far as changing, I'm with Vil_Riker-- put a little less than rated in, start it up, back it off the ramps, let it fill the filter then sit for a bit. Check and top off.

GM dipsticks used to be, and might still be, calibrated with a quart between add and fill lines. This is because oil used to come in cans that couldn't be resealed. So run the car down to "Add", open a can with a church key, glug that all down in, and you're back to "full." This has the added bonus of making consumption of less than a quart between OCI's "acceptable" to them. With all that being written, one may presume that going around a quart low is on the fringe of acceptability. As long as you don't pull so many G's you starve the engine of oil, it is.

 

[50yr Street Mech]

Church key was for a beer can, not an oil can. Oil can openers had those bulky things with the blade that cut thru the can and was tapered to a funnel looking thing. WOW, I"m friggin OLD !!!!

 

[Smoky14]

I remember the Mason Qt. jar with a funnel screw on top for oil. That fancy can piercing spout was new fangled stuff.
Smoky

 

[SC Maintenance]

1) If your not having to top off between changes I would not worry about oil consumption. I more or less know by how much comes out. On my Nissan's 5.5 quarts go in, more then 5 quarts come out. Close enough. If you have an oil burner keep track of how much you top up between changes.

2) Fill check - Check your manual. The procedure can be a little different for each. Some want you to turn in a specific order, some don't.

3) Fill level - Try what the manual suggests then check. If its not where you like it exactly, add or decrease next time.

4) Don't overfill and you wont need to worry about it.

 

[50yr Street Mech]

Yeh Smoky, we're dating ourselves