Hot answers tagged

81

It's a BAD idea! The oil is contaminated with impurities that will not do the fueling system on your car any favors. Further, it's bad for the environment because your car is NOT designed to burn oil even if it's mixed with gasoline. The best thing to do is to take the used oil to a place where it can be recycled into new oil and used again. Most oil ...


68

Engine oil does much more for an engine than lubricate. It provides cooling, cleaning, and a bunch of other chores. You already know engine function is degraded when you run out of oil. Let's see if we can run it down to make more sense for you how it happens. Let's say, for lack of argument, your engine is running with very little to no oil. The engine ...


28

Per @Eric Urban's suggestion, I found the Technical Manual for the M4A3 tank published in 1942. That tank did use the aluminum Ford GAA 18L V8 engine which produces 500 hp at 2600 RPM! It says: Capacity: 32 Quarts Above 32°: SAE 30 32° to 10°: SAE 30 or 10 10° to -10°: SAE 10 Below -10° : Not Listed Replace the oil every 50 ...


28

You should generally go by the manufacturer's instructions, the car's handbook should specify the change interval - but I don't know of any modern car with that low an interval. Therefore you should top it up unless you're near the interval. Saying that, if you've lost a significant amount of oil in that time, I'd want to be investigating why...


27

I would not start an engine that has the oil overfilled by a gallon. You can cause permanent engine damage by significantly overfilling the engine with oil. If the crankshaft and connecting rods are contacting the oil, they will whip air into it and cause it to foam. This happens when the oil level is too high. Foamy oil may still work as a barrier ...


27

Yes, it could go that far ... it really depends on the condition of the oil and the engine when the oil dropped, but yes it absolutely could go that far. As a side note ... If she was able to get it 40 miles, that engine is completely toast and will require at a minimum, a complete rebuild. The easier bet here would be to just get a replacement engine from ...


24

The seller should not be selling the vehicle with oil in the cooling system. That supposed "quick fix" should have been rectified at the earliest opportunity. Have him flush the cooling system and put another few tens of kilometers on the odometer before you even consider such a vehicle. If the seller is topping off the radiator with oil instead of water, ...


22

If you want to know what to use for your car, follow what your vehicle manufacturer has stated. If you would like to better understand what all the gobble-de-gook means, continue reading --- Oil Originally there was crude oil. Black gold. Texas Tea. As crude oil, it is fairly much useless. It's the distillates which make up the usable parts. Crude oil is ...


22

I would be more concerned about whether engine oil is actually finding its way into the radiator from the engine. If it is, this would be indicative of a compromised head gasket, warped cylinder head, or damaged oil cooler (if the car uses radiator coolant for cooling the oil). The first two items are not trivial to replace or fix. The third one isn't far ...


21

Towards the diagnosis end of things, there are some general guidelines to follow: If you are seeing smoke coming from your exhaust, what color is the smoke? If it's blue, then it's oil If it's black, it means you are running rich (too much fuel). If it's white, the car may be burning antifreeze or (quite rare) auto-trans fluid. Since it's blue smoke you ...


20

You Asked What are the benefits of a dry sump? Simply put a wet sump crankcase has oil sitting in the bottom of the crankcase. It's affected by various forces as the car or motorcycle is driven. At times it is possible, during hard braking or cornering, that the oil pickup is not in oil, resulting in a low or no oil pressure condition that could ...


20

If it is burning it's oil, the oil is getting somewhere it shouldn't do - and changing the plugs and coil will make no difference to that! As the oil smoke is coming out of the exhaust, that suggests to me that the oil is getting into the cylinders - the most likely causes for this are a blown headgasket, failed valve stem seals, or failed piston rings. A ...


20

The approximate answer for the cars that I have driven that take the standard 5-6 quarts is "about 2 quarts low". Maybe more, maybe less. Normally, you'll notice the light come on when taking a sharp corner as the oil sloshes to the side and the oil pump sucks air for a second. But, the major point here is that the light means "low oil pressure", not just ...


18

In most engines, when you fill the oil, it drains into a reservoir on the bottom of the engine known as the oil pan. The tube for the dipstick goes right down into this reservoir to measure the level of the oil. The other important item located in this reservoir is the pick-up tube for the oil pump. As long as the pick-up tube for the pump stays under the ...


17

It's a Diesel, which means that you usually have a high detergent oil in an engine that dumps combustion by-products like soot into the oil as part of its normal operation. Given the age of the vehicle I'm not surprised that the oil has noticeably darkened after 10 miles - one of the older Diesels I owned a while back did that during the time it took to run ...


17

With way too much engine oil in the engine, the problem is that the crankshaft can hit the oil in the bottom of the crankcase when the engine is running. Since the crankshaft is spinning fast, even at idle, each time it slaps the surface of the oil, it will create some bubbles in the oil as the air just behind the spinning crankshaft lobe gets dragged under ...


16

In a word: No. To add more to it: Absolutely Not. There is one huge thing which you have not taken into account. That being carbon which deposits from the air/fuel mixture burning process. Where does it go? Right into the oil (among other places). A small amount of blow by occurs which also forces this mixture down into the crank case. Now you have it in ...


16

The below are very easy checks you can do while buying a used car.(from anywhere for that matter of fact) Engine This is the most complicated/expensive part to maintain/replace. Head Gasket check: Open the oil filler cap or the dip stick for any milky white substance, like mayonnaise, if it is present then stay away, it means the head gasket is broken and ...


16

Thin oils tend to have a very poor shear stability, especially when they are hot. The function of the oil is to protect and lubricate the engine and ancillaries (i.e. turbo chargers). In certain applications it also makes up some (where an oil cooler is employed) or all (for aircooled engines such as the Beetle) of the circulated liquid cooling system. I'...


15

The 3000 mile oil change interval is a US-specific consumer deception so widely practiced that it has become accepted wisdom. It creates enormous revenue for dealers and garages. Outside the US, most people change their oil far less often. In fact, manufacturers such as Ford routinely specify oil change intervals of up to 10,000 miles or even more for ...


14

Normally, I would ask first in a comment but that seems to be a privilege not available to new users, so here goes: Are you sure it was the radiator cap and not the overflow bottle? The radiator is usually full and getting 100ml in would be a struggle, not to mention that the green coolant would be staring you in the face. If you radiator wasn't full then ...


14

Simple answer - no, you can never get rid of ALL of the old oil - and you wouldn't want to, as you need to keep a film of oil over all the moving parts all the time. The small amount of residual oil will mix with the new oil quite happily. Oil flows better when it is warmer (as it gets thinner), so the best way to get as much of the sludge and residue out ...


14

Number one answer is always Head Gasket. The reason is that there are oil and water passages in close proximity, being separated by a gasket (which might just be flimsy paper or rubber, but is often steel or copper) sandwiched between two pieces of metal with (usually) different thermal expansion rates. This means that any time your engine gets far enough ...


14

Here's a "tip to make sure I got everything right" for the future. One that I use myself, and taught my Auto Tech students as well: The very first thing is to take off the oil cap, and place it over the latch area for the hood, such that you can't close the hood unless you move the cap. This prevents the worst possible thing: finishing the job but ...


13

The most likely source is the head gasket. There are very few other ways (short of catastrophic engine failure - and that would give other symptoms!) of the two mixing. Check for excessive smoke (oil getting into the bores), coolant loss (coolant getting into the bores) and a mayonnaise effect in the oil (coolant getting into the oil) You don't say what ...


13

tl;dr: This procedure checks the oil "reserve" remaining in the pan after all moving parts are lubricated. This procedure is purely vehicle dependent. For example, on my car, I'm supposed to check the oil when the engine is cold. In asking you to check when the engine is hot, the oil will not be pooled in the oil pan. Instead, it will have been fully ...


13

Yes, it's possible some of the seals designed to withstand water and glycol could get damaged I am thinking you are creating a fictitious scenario here, so I'll roll with it. If you filled your radiator with oil and started your car and let it run for awhile I would be most concerned with damage to seals that were designed to withstand water and glycol. ...


13

It definitely could have worked it's way (the drain bolt) over the three month period from the previous change. The cause would be an improperly torqued oil drain bolt. It wouldn't be the first time. Getting together evidence that it IS their fault is impossible. So, to clearly answer this question What could cause the oil plug to just come out, if ...


12

About a quart - have I ruined my car? In short, no. If you read the answers on this similar question, even a gallon of extra oil generally won't ruin a car. This is what I suggested and still recommend: If the oil isn't hot, almost any sort of plastic tubing can be used for siphoning. It's easiest to go in via the dip stick. Remember not to use ...


12

Recycle it. Don't use it for anything, it's an environmental hazard. Just get rid of it in the least impactful way. Used motor oil has a plethora of bad chemicals and compounds in it that eliminate for another use once it has been inside your engine for an extended period of time. Aside from the hydrocarbons there is lead, phosphorous, berium, zinc, ...


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