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82 votes
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Top off gas with old oil, is that bad?

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 ...
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72 votes
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What actually happens when there is not enough oil in a car engine?

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 ...
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28 votes
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proper oil for 1940's era aluminum ford engine

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: ...
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28 votes

Is it alright to top off with oil instead of changing after 3000 miles?

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 ...
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27 votes

Seized engine due to being run without oil

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 ...
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24 votes
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How to understand different engine oils?

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 ...
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24 votes

Will having a radiator full of engine oil do damage to the motor?

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 ...
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23 votes

What does exhaust smell on oil and transmission dipstick mean?

First of all you're not smelling CO (carbon monoxide) as that is an odorless and colorless gas. What you are likely smelling are combustion byproducts and that is not at all uncommon in the engine ...
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23 votes
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Switching engine coolant with similar properties oil

There's a very straightforward answer to this question: Water has a much, much higher capability to transfer heat than oil. Even if you were able to overcome the safety and design issues brought up ...
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22 votes
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What causes an engine to burn oil?

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, ...
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22 votes

Will having a radiator full of engine oil do damage to the motor?

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,...
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21 votes
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How low does the oil level have to get to trigger the low oil light?

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 ...
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20 votes
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What are the benefits of a dry sump?

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. ...
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20 votes

Why has my car burnt through all the oil?

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 ...
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  • 28.6k
19 votes

What actually happens when there is not enough oil in a car engine?

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 ...
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18 votes
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Second hand car - Engine/Tyres/Etc

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: ...
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18 votes
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What actually happens when there is way too much oil in a car engine?

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 ...
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16 votes

Is topping up the oil enough of an oil change?

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 ...
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16 votes
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Why don`t we use extremely thin oils in engines

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 ...
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15 votes

Is it alright to top off with oil instead of changing after 3000 miles?

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 ...
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14 votes
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How do I troubleshoot the source of oil in my coolant?

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 ...
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  • 1,925
14 votes

How do I tell if I screwed up my oil change?

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 ...
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  • 12.3k
14 votes
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Is it necessary to replace an oil filter every oil change?

You need to change the oil filter every oil change. In fact some of the longer lasting oils like Amsoil suggest you change your filter out at normal change intervals if you don't use their filters. ...
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13 votes
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Does Vaseline dissolve rubber?

tl dr - Have no fear of Vaseline and o-rings O-rings are made out of many different materials. I would suggest that those o-rings which are made to work in the automotive realm are made to be ...
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13 votes

Will having a radiator full of engine oil do damage to the motor?

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 ...
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  • 32.8k
13 votes

How can an oil plug just fall out after three months and 3,000 miles and the car has just 35,000 miles on it, 2014 Ford Escape

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....
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13 votes
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Why are recommended oil weights lower for many newer cars?

Two words, fuel economy. Using a thinner oil allows manufacturers to eek out a little more fuel economy. Thinner oil flows a little easier and has a little less resistance. To use the thinner oil, ...
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13 votes
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Does engine oil get old and go bad?

Short answer .... NO !! Now this is one of those seriously contentious topics that people will chime in from all walks of life, experience, and voodoo. I will speak [yell] my piece, and put on my ...
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  • 12.3k
13 votes

Top off gas with old oil, is that bad?

All modern cars scavenge blow-by including oil vapour and a mist of droplets. This is good for upper cylinder lubrication and does extend ring and bore life. If you have to, you can install a catch ...
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  • 406
13 votes

Top off gas with old oil, is that bad?

Aside from the numerous reasons not to do this to your car I would like to offer you a solution to your perceived problem. Don't take the old oil back to the store. At least not right away... Your ...
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