Hot answers tagged

81 votes
Accepted

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
72 votes
Accepted

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 ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
28 votes
Accepted

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
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 ...
Nick C's user avatar
  • 28.7k
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
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 ...
dotancohen's user avatar
  • 1,723
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 ...
jwh20's user avatar
  • 12.1k
23 votes
Accepted

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
  • 1,134
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,...
Zaid's user avatar
  • 39.1k
21 votes
Accepted

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
  • 13.3k
20 votes
Accepted

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. ...
DucatiKiller's user avatar
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 ...
Nick C's user avatar
  • 28.7k
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 ...
JPhi1618's user avatar
  • 13.3k
18 votes
Accepted

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 ...
Edward's user avatar
  • 2,847
16 votes
Accepted

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
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 ...
ajay's user avatar
  • 151
15 votes
Accepted

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
  • 24.9k
14 votes
Accepted

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 ...
Jim W's user avatar
  • 1,935
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
  • 12.4k
14 votes
Accepted

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
13 votes
Accepted

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 ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
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 ...
DucatiKiller's user avatar
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....
DucatiKiller's user avatar
13 votes
Accepted

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
Accepted

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
Accepted

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
  • 1,197
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
Accepted

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

Only top scored, non community-wiki answers of a minimum length are eligible