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Should I use open engine oil that was left over from previous oil change

If the oil is unused, and unopened, there is nothing wrong with using it. ExxonMobil recommends a five-year maximum shelf life for engine oils, including Mobil 1™ synthetic motor oil. Opened ...
CharlieRB's user avatar
  • 9,015
10 votes

Should I use open engine oil that was left over from previous oil change

Yes, as Charlie says, as long as it has been stored correctly it should be fine. I generally use the leftovers from one change when I do the next so that it's not sitting around for too long - e.g. if ...
Nick C's user avatar
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8 votes
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Effects of sunlight on engine oil

Engine oil is normally kept inside a light-proof steel box (your engine), so you might not find much information on how it's affected by sunlight. However, other industries use lubricating oil that ...
JPhi1618's user avatar
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7 votes

Is WD40 a penetrant?

http://www.jalopyjournal.com/forum/threads/best-penetrating-oil-for-stuck-nuts-bolts.773380/ There was a study done on penetrating oils. Here's the highlights - The break out torque required for: ...
rpmerf's user avatar
  • 8,403
7 votes
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What type of Brake Lube to use

Two lubes are needed to properly lubricate caliper type brakes. Silicone is used on the slider pins and anything that touches rubber. A generous amount that completely coats the pin, hole wall and ...
Fred Wilson's user avatar
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6 votes
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Which grease should I use on wiper mechanisms?

Use the lithium or silicone grease! Copper grease is primarily used to prevent the seizing of parts which become extremely hot, like the exhaust system. But it is not a lubricant in first place. The ...
sweber's user avatar
  • 7,057
6 votes

Is WD40 a penetrant?

WD40 is not a penetrant, and as far as lubricants go, it's a poor one. Get a legit penetrating oil at the car parts store. They come in spray cans and range from $7 to $15.
tlhIngan's user avatar
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5 votes

Should I use open engine oil that was left over from previous oil change

A bit of a late answer here, but I would agree with the answers already posted: Yes, you can definitely use it. That being said, I would not recommend storing engine oil for more than a few years, ...
anonymous2's user avatar
  • 5,235
5 votes

Will greasing clutch parts make it softer

Don't try greasing anything inside the bell housing. Grease will get thrown onto the friction plate and cause you problems. If the pressure plate is faulty or a previous owner had a heavier plate ...
Solar Mike's user avatar
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5 votes
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Grease/lubricate rubber stabilizer bar bushings?

In the seldom cases I saw them the manual advised to use soapy water to install them as petroleum based lubes degrade rubber. Normally grease is included on items that need it. Make sure to torque ...
Martin's user avatar
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5 votes
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Assembly lube for engine that has been sitting for years

As you suggested, absotutely use assembly lube on the parts you've taken apart and cleaned. This will ensure there's no wear there while the parts are waiting on oil pressure to build-up and lubricate ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
5 votes

can i use api CJ-4/SN in a gasoline car?

Your annual temperature range is -10C to 35C. The oil viscosity of 15W-40 means that the oil is no thicker than straight SAE 15 oil at winter temperatures and no thinner than SAE 40 weight oil at 100C....
MTA's user avatar
  • 6,639
4 votes

Does Vaseline dissolve rubber?

Yes it might, if it's made from Ethylene Propylene Diene Monomer (EPDM) like what is used on some MAF sensors. It might make your o- ring swell larger so it won't fit correctly anymore.
Baas's user avatar
  • 39
4 votes

Is Anti-Seize a lubricant, abrasive, or both?

Too many either overthink the problem at hand, or have a perverse tendency to distrust "the man," i.e. whoever is determining the current paradigm. Hence, any variety of satisfactory answers are ...
old coot's user avatar
4 votes

Should I use lubricant or not when installing these spark plugs?

I always use anti-seize whenever I'm installing spark plugs of whatever type for several reasons: If installing spark plugs into aluminum heads, it helps prevent pulling the threads out with the ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
4 votes

What is the first point of failure on an engine?

Piston rings are first to wear out most of the time. They are under much mechanical and friction stress, poorly oiled, and subjected to combustion particulates. Valve stems seals are under no ...
Fred Wilson's user avatar
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4 votes
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Is it bad to roll down a hill at highway speed in neutral or with the clutch pedal down in a manual transmission?

If the transmission is in neutral and the clutch engaged, then if the input or primary shaft of the gearbox drives a pump the box will get lubrication, if the box relies on splash lubrication then it ...
Solar Mike's user avatar
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3 votes
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Should I use lubricant or not when installing these spark plugs?

It's ok to use the lube if you know what you are doing. Both NGK and BRP are correct, but it's important to understand where the disagreement in these recommendations comes from. First of all, let's ...
ZenJ's user avatar
  • 146
3 votes
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Can motorcycle engine be tilted by 90 degrees?

I can only really give you a general answer, since every engine is different. Yes, you're correct in thinking that with a wet sump engine, gravity is what returns the oil to the pan in most scenarios. ...
raydowe's user avatar
  • 3,012
3 votes

Do good shocks have any oil below the top half?

A shock absorber is supposed to be dry on the outside, leaking fluid (I suppose you mean that by grease?) is a sign of damage. The more hydraulic fluid a shock absorber looses the worse is it's ...
Martin's user avatar
  • 8,458
3 votes
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Oil low - incorrect oil already in. Stick with the wrong type or add correct type?

It's fine to run Synthetic Oil with crushed Dinosaurs, which is exactly what 'part-synthetic' oils are - but because the chemistry of the two oils you have is unknown, I wouldn't do it for too long (...
PeteCon's user avatar
  • 8,712
3 votes
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What are the dangers of too high TBN?

You might want to read the article here: TBN Discussion But the key point on too high a TBN number is: So should we all use a High TBN oil? There are advantages, but there are also ...
jwh20's user avatar
  • 12.1k
3 votes
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Is car motor being lubricated with ignition off?

I have never come across a car that has an electric oil pump, but there are bound to be some special cases out there. So the mechanical oil pump should be working. You really need to say which car ...
HandyHowie's user avatar
  • 25.4k
3 votes

Is there any particular advice on crank-bolt lubrication I should know?

No lubrication. Just ensure it is clean and dry (to include the threads on the crankshaft). This will get you the most accurate torque value.
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes

How does ambient temperature affect engine efficiency and fuel consumption?

When taking an engine running on otto's thermodynamic cycle (the work gained for each cycle is the area inside the P(V) diagramm) against the same load and with optimal running temperature everywhere ...
Talenduic's user avatar
2 votes

How to stiffen up a loose ball & socket joint for a motorcycle mirror?

Very low tech solution - I had a bicycle mirror with a loose ball and socket joint. Pulled the ball out, put it in a plastic-wrap baggie, and pushed it back in. Trimmed off excess baggie... Mirror ...
BikinHowd's user avatar
2 votes

How to stiffen up a loose ball & socket joint for a motorcycle mirror?

Apply a thin layer of solder/alloy weld to either the ball or socket to increase/decrease the relative diameter of the joint contact area and in effect create (closer to) the correct tolerances for ...
Stuart's user avatar
  • 21
2 votes

Does Vaseline dissolve rubber?

Not all oils rot rubber, for example transmission oil or brake fluid does not rot rubber. However engine oil will. That's why if one uses engine oil for brake fluid or in their power steering pump, it ...
John's user avatar
  • 21
2 votes
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How to tell the Difference: Condensation Drain Vs Lubrication Hole

I'm going to go with an educated guess here and say these are condensation drains. This is based on two things: These holes are on the bottom. Usually when they are lubrication holes, they are on the ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
2 votes
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Engine oil requirements

If the oil is too 'light', then it will be too thin when hot. Ambient temperature absolutely affects engine temperature, or at least it can. That is counteracted to a large degree in a modern, water-...
Kyle Baker's user avatar

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