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79 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 ...
jwh20's user avatar
  • 12.1k
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: ...
Zach Mierzejewski's user avatar
27 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 ...
Nick C's user avatar
  • 28.8k
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 ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
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 ...
dwizum's user avatar
  • 1,144
22 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 ...
jwh20's user avatar
  • 12.1k
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 ...
JPhi1618's user avatar
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15 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 ...
Steve Matthews's user avatar
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 ...
SteveRacer's user avatar
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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. ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
14 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 ...
ajay's user avatar
  • 141
14 votes
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What's the black knob near the oil pan?

If your engine is the 2.7 litre, then that is the oil filter. You can see this in this video detailing how to do an oil change on the 2.7 litre engine. The oil filter may just need tightening a little,...
HandyHowie's user avatar
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13 votes
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If you change your oil with synthetic can you never safely go back to using conventional?

This is a myth. A lot of old-school mechanics and non-chemistry educated people repeat this false myth. When changing from synthetic to regular oil, there is not anything special that you need to do ...
cloudnyn3's user avatar
  • 3,343
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, ...
vini_i's user avatar
  • 16k
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 ...
SteveRacer's user avatar
  • 12.4k
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 ...
mckenzm's user avatar
  • 416
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 ...
MonkeyZeus's user avatar
  • 1,187
13 votes

Does a, “5% oil life remaining” dash message mean low quality or low quantity, or both?

Realistically, it doesn't mean either. The life expectancy is just that, how long you should be able to continue to use the oil which is in there. There is nothing wrong with the oil. It will ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
13 votes
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Oil Pan Flap? What does it do?

The flap allows oil to move freely in one direction and slows it down going the other. The free direction of flow is usually towards the oil sump pickup. This helps ensure there's a ready amount of ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
12 votes
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Is an "oil life indicator" a reliable indicator for when to change the oil?

To the Mechanic suggesting 3000 mile changes, that recommendation has changed considerably. Several articles and studies have been done disproving the necessity of the 3k change. On any vehicle in ...
Eric's user avatar
  • 136
11 votes

What is causing my oil pan to fill with a mysterious fluid?

Used motor oil should smell like oil, or oil and exhaust. If you can smell gasoline, you have fuel in the oil. You said the car sat for a long time. If this engine has not been modernized with fuel ...
MTA's user avatar
  • 6,973
10 votes

2011 Jeep Liberty ran without oil, did this cause my engine to blow?

Your oil pan didn't rust I would just like to point out that your oil pan can't just rust out. It is made of material that doesn't rust. So when you had a hole in your oil pan it more than likely ...
DucatiKiller's user avatar
  • 32.9k
10 votes

Oil Cooled vs Water Cooled

I am assuming that by cooling you are referring as to which Engine cooling systems are better in particular scenarios... Oil-cooled: Traditional Oil-cooled engines are most commonly found in passenger ...
Jay Vyas's user avatar
  • 101
10 votes

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

based on the no information you gave, no manufacturer recommends changing oil every 3000 miles. Some go as high as 7000 (Toyota) but 4000 is fine for city. If you are losing oil however, you are ...
John Lord's user avatar
  • 600
9 votes
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How do I tell if I screwed up my oil change?

I believe you just dripped some oil on your exhaust when drained it, don't worry, and your "paranoid" stuff is good - it means you care. Good job Snake! ;)
Arturs Bolsunovskis's user avatar
9 votes

How long does it take for engine damage to show up after running without enough oil?

There is no clearly defined time after which low oil damage will become apparent. But your experience sounds typical to me. There are any number of Youtube videos that show running engines without ...
jwh20's user avatar
  • 12.1k
8 votes
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Oil Cooled vs Water Cooled

Oil Cooled and Water Cooled are terms used by Manufacturer's to differentiate the slight difference between the cooling systems. Note that this is specific to only motorcycles as almost all of the ...
Shobin P's user avatar
  • 8,946
8 votes

proper oil for 1940's era aluminum ford engine

Given the changes in oil formulations since the time this beast was built and now, I'd consider a change in the oil. Straight-weight oils as formulated then and now are considerably different. Were ...
user23543's user avatar
8 votes

I put transmission fluid in my engine; what to do about it?

Putting transmission fluid into your engine shouldn't have hurt anything, and as you've found out, may help it a little by cleaning stuff out. Obviously, it's not necessarily a good thing, especially ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
8 votes
Accepted

Is it important for oil to be present while engine is off?

There is no problem with an engine sitting with an empty sump - after standing for a few days the oil will all have run back down to the sump and so won't be doing anything anyway. I'm afraid I'm ...
Nick C's user avatar
  • 28.8k

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