Questions tagged [oil]

This tag should be used for anything related to the use of automotive engine oil, or in reference to other parts of the car that also require lubrication using oil.

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60
votes
9answers
727k views

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

When a car is topped up with oil, it clear to most people that you are supposed to fill it to the recommended amount as specified by the manufacturer (normally on a dip stick). What exactly are all ...
42
votes
4answers
107k views

How far can I drive with 1 gallon too much oil?

I have way too much oil in my Acura TSX. Do I need to take care of it without turning it on or can I drive it to a service station? If I need to do it in place, I don't have the ramps or a pan or ...
28
votes
2answers
14k views

Do I have an oil leak if I have to add oil?

I don't change the oil all that often (maybe every 8000 miles) and on my 10 year old car the oil light comes on and I need to add a quart or two (and then I start thinking I practically changed the ...
28
votes
4answers
499k views

What causes an engine to burn oil?

What are the different problems that can cause an engine to burn oil and in general how difficult / expensive is each one to repair? How do you diagnose each potential cause? I found this article ...
26
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4answers
470k views

What actually happens when there is way too much oil in a car engine?

I saw the answers to a question I posted recently highlighting the disadvantages of having too little oil in an engine, but that got me wondering what if the complete opposite were to occur! I know ...
25
votes
6answers
208k views

What are the risks of overfilling a small engine with oil?

I recently overfilled a 4 stroke lawnmower engine with oil. It has been run for about 1.5 hours while overfilled. It smokes a lot right after being started but after 30 seconds or so the smoke clears. ...
21
votes
4answers
4k views

What are the benefits of a dry sump?

I've heard references to dry sumps, usually in reference to racing engines. But more recently I came across an article about a 'supercar' which stated that it had a dry sump. What are the benefits of ...
21
votes
4answers
3k views

proper oil for 1940's era aluminum ford engine

I would like to know the proper oil to use in a Ford GAA engine from around 1945. Could be as late as 1958. From a series of photos of a GAA being restored on Flickr. Currently this engine has all ...
21
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5answers
13k views

What differences between synthetic and dino oil?

What are the main differences between synthetic and dino oil? Is one always better than the other?
20
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3answers
12k views

Is it worth switching to full synthetic or blend oil in my older car/truck?

I have an older (enter vehicle here) that has 100k miles on it. Would I see any benefit switching to full synthetic or synthetic blend oil? Is it worth the extra cost in an older vehicle? For ...
19
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4answers
677k views

Will Putting An Extra Quart of Oil In My Car Ruin It?

I put too much motor oil in my car's motor. About a quart - have I ruined my car? I've been driving it. I know I need to get the oil drained. But I'm worried that I've ruined my car which has been ...
19
votes
6answers
40k views

Is it OK to mix oil of different viscosity in a Wankel engine?

I have a Mazda RX-8 (with a Wankel rotary engine). Mazda advises North American owners to use 5W-20 oil. The engine was just replaced 200 miles ago by the dealer so it currently has 5W-20 in it. ...
18
votes
10answers
68k views

Engine oil change and getting rid of old oil completely

After running the vehicle for a certain distance usually we will change the engine oil. This will not only give engine new life with the brand new oil but will also get sludge and other sediments out ...
18
votes
4answers
9k views

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

We had an oil change done at a quick lube type shop. After nearly 3 months and 3,000 miles driven, the oil drain plug fell out, resulting in blowing up the entire engine. There was no oil leakage or ...
17
votes
8answers
19k views

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

I've got one question; I was looking over this car that I was going to buy and there was engine oil in the radiator. I asked the guys why it was in there and he said he didn't have enough coolant to ...
17
votes
6answers
5k views

Seized engine due to being run without oil

I have a 2004 Trailblazer. My daughter called and said the oil pressure dropped to nothing and it died and wouldn't start. My husband checked it and said she had hit something hard enough to rip the ...
16
votes
9answers
103k views

Is an “oil life indicator” a reliable indicator for when to change the oil?

I have a 2014 Honda Pilot with 3600 miles on it. Historically I have always changed oil in my vehicles every 3000 miles, using good quality non-synthetic oil. Now this Honda has an "oil life ...
16
votes
3answers
3k views

Why has my car burnt through all the oil?

I have recently run in to trouble with my Vauxhall Corsa 1.2 2013. I broke down the other day after a huge cloud of white smoke out the exhaust followed by a severe loss of power. The AA came had a ...
15
votes
4answers
148k views

Why check oil when engine is at operating temperature?

The owner's manual to my VW Golf Mk7 states With the engine at operating temperature, park the vehicle on a level surface to ensure that the engine oil reading is correct. Why is it important for ...
15
votes
1answer
35k views

If you change your oil with synthetic can you never safely go back to using conventional?

I know that sounds like a weird question but I was talking to my brother in law about oil changes and I mentioned that I almost always use Mobil 1 full synthetic. He replied, "make sure you keep ...
14
votes
3answers
11k views

How do I select the right oil for my car?

I can give you my cars make and model and the conditions that I drive in, but I'm looking for a general guide to selecting the right oil for a car. I'm not really knowledgable when it comes to cars so ...
14
votes
2answers
2k views

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

I would like to know the step by step troubleshooting procedure for discovering the source of oil appearing in coolant. There are several different points of failure that can be the root cause for ...
14
votes
5answers
87k views

Oil burning smell and slow oil leak

I am wondering what types of issues I am most likely looking at with this; My 2003 Ford Escape (V6) has an increasingly pronounced burnt oil smell that has developed slowly over a year or so, coupled ...
13
votes
3answers
45k views

How low does the oil level have to get to trigger the low oil light?

I had an engine shudder during my idle after startup yesterday morning. I checked my oil level and was a full X cross hatch height below the min oil line. I added 1.5 qts to get up to the max line. It ...
12
votes
6answers
11k views

What happens if unsuitable oil is used in a vehicle engine?

I recently heard an urban legend-like story about a guy in a developing country who decided engine oil was too expensive and so used some vegetable oil instead. The story says the car ran for some ...
12
votes
4answers
35k views

Does Vaseline dissolve rubber?

Recently, someone suggested that I apply some vaseline to an O-ring connection to see if I can find a leak. I've read that oil-based lubricants, especially vaseline, can desolve rubber. It seems like ...
12
votes
6answers
81k views

Is it normal for the oil to be dark in color right after an “oil change” in a 10-year old diesel car?

I took my 2002 Jetta TDI wagon to a neighborhood shop about 10 miles, 24 hours ago. They supposedly changed the oil, but the color is very dark, almost black. Definitely not light-colored/transparent. ...
11
votes
5answers
3k views

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

I just changed my oil in my 2500 HD Silverado for the first time by myself. I've changed my oil in a 2004 Toyota Camry a handful of times, but I always had a friend supervise me. I need to know common ...
11
votes
6answers
3k views

What can I do with used motor oil?

Besides recycling? I've heard, for example, that I can use it to lubricate the drive chain (in a motorcycle / bicycle), but that doesn't appeal to me.
11
votes
3answers
4k views

Why don`t we use extremely thin oils in engines

I understand that lower viscosity oils are way easier to pump and move around engine parts, also they form a thinner "film" on friction surfaces which could improve parts measurements precision etc. ...
11
votes
6answers
1k views

Second hand car - Engine/Tyres/Etc

I am looking into buying a second hand car from a reputable Mercedes-Benz dealer (not just some dodgy salesman by the side of a road lol....). Anyway, there are a few maintenance/mechanical things ...
11
votes
6answers
34k views

Is the vent from the pcv valve back into the air intake really needed?

After working on my car, I didn't bother to reattached the line from the pcv valve into the air intake before testing the motor. It ran normally. This made me question whether I need to even return it ...
11
votes
1answer
45k views

Does engine oil get old and go bad?

Does engine oil actually go bad from just sitting within an engine that's not getting use? I feel conventional motor oil has been sitting underground for millions of years prior to being extracted and ...
11
votes
1answer
657 views

2005 Subaru 2.5 RS - Engine-wise, how damaging is burning oil?

Assuming that an engine always has enough oil to be lubricated properly but burns quite a bit of oil, can it cause any damage in the long-term because it doesn't belong in the combustion chamber? I ...
10
votes
4answers
57k views

How to understand different engine oils?

When I went to shop for engine oil, I found many types as such: 5W-30 A5 5W-30 A1 5W-20 SAE 5W-30 10W-30 Also I see other information such as: Fully Synthetic Semi Synthetic Oil Synthetic ...
10
votes
3answers
70k views

Accidentally poured engine oil into the coolant reservoir

My 1990 Mazda 626 leaks oil like a sieve, so I regularly top up the oil. In a moment of stupidity, I opened my radiator cap instead of my oil cap while topping up my engine oil, and poured about 50-...
10
votes
3answers
85k views

Okay to add new oil to old?

Title pretty much explains, I change my oil every 4-6k miles depending on how generous I’m feeling, however will the oil dirty oil that’s already in the sump mix with the clean oil when topping up? ...
10
votes
2answers
6k views

How does the change oil light system work and does it matter what type of oil you use for it to work properly?

I want to know if the methods a vehicle decides when to turn on the oil change light have to do with the qualities of the motor oil used in the last oil change. I have heard that the vehicle's ...
10
votes
1answer
652 views

Why are recommended oil weights lower for many newer cars?

I've noticed that the recommended motor oil weights for cars in the last 5-10 years are often lower than earlier models. It seems like 10w-30 used to be almost ubiquitous in the 80s and early 90s, but ...
10
votes
1answer
22k views

Does synthetic oil expire?

I just bought a bottle of Castrol Edge oil for topping up. The oil is advertised as being 'Fully synthetic', I don't really know what that means but it was produced sometime in 2012. That seems like ...
9
votes
3answers
215k views

Oil in coolant - how much trouble am I in?

I have oil in my coolant reservoir. Could it just be the head gasket or is it almost certainly the entire engine or might it be something else entirely? Thanks in advance...
9
votes
12answers
138k views

Is it necessary to replace an oil filter every oil change?

I understand the oil filter's job is to remove contaminants from the engine and that it holds some oil in it from the previous oil; however, is it really necessary to replace this every oil change? ...
9
votes
3answers
46k views

Is topping up the oil enough of an oil change?

If you use synthetic ester-based oil in a relatively new petrol engine, top it up regularly, and the engine runs very quietly and basically without any noise whatsoever (especially after another top ...
9
votes
3answers
20k views

Is it safe to reuse oil that was drained for a repair?

Let's say that I just replaced my engine oil but decided I want to lift the valve covers to do some gasket replacement. I know it may sound cheap but I'd rather not throw away $25 worth of almost new ...
9
votes
2answers
13k views

How to test if oil is leaking into combustion chambers?

How can I test whether oil is leaking into cylinder combustion chambers and getting burnt in case of oil level loss? As opposed to, for example, leaking through the oil pan or the timing chain cover.
9
votes
5answers
843 views

How can I know if the right oil has been added to the vehicle?

Considering that the car recommends Mobil 1 Synthetic oil as per the logo on the oil cap, how can I be sure the garage that did the oil change poured the recommended oil and not another low cost oil ...
9
votes
1answer
31k views

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

I have a 2001 Mitsubishi Eclipse Spyder GT with the V6 engine. The last oil change was 1 week ago. My red oil light came on, and I read the dip stick and thought I was a quart low on oil. Really it ...
9
votes
3answers
18k views

I used 0W-30 instead of 0W-20. Is it serious?

I have a Nissan Sentra 2014. I wanted to start using full synthetic oil, and the manual said I should use 0W-20. I changed both the oil and the filter (I used this one), and after finishing I realized ...
9
votes
2answers
499 views

Can leaky cylinder explain oil loss to burning?

One out of the 6 of my Toyota Tacoma cylinders is mildly leaking, as indicated by a cylinder leakdown test. While other cylinders are leaking only something like 5-10%, this one leaks about 20% of the ...
8
votes
8answers
23k views

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

is it ok to top off or change the oil after 3000 miles? My husband said that I was 2 quarts. low so he added two quarts. My question is should we have just changed the oil completely or just added ...