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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28
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9answers
6k 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 ...
24
votes
4answers
45k 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 ...
24
votes
2answers
7k 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 ...
18
votes
3answers
5k views

What differences between synthetic and dino oil?

What are the main differences between synthetic and dino oil, and is one always better than the other?
17
votes
7answers
65k 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. ...
15
votes
8answers
2k 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 ...
15
votes
4answers
157k 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 ...
15
votes
5answers
30k 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. ...
14
votes
4answers
1k 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 ...
13
votes
4answers
7k views

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

I have a older (enter vehicle here) that has 100k miles on it. Would I see any benefit switching to full synthetic or synthentic blend oil? Is it worth the extra cost in an older vehicle? For ...
11
votes
3answers
7k 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 ...
11
votes
7answers
10k 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 ...
11
votes
1answer
344 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
2answers
1k 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 ...
9
votes
5answers
837 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 ...
9
votes
2answers
3k 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 ...
9
votes
5answers
145 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.
9
votes
4answers
34k 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 ...
9
votes
4answers
32k 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 ...
9
votes
3answers
231k 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 ...
8
votes
5answers
22k 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. ...
8
votes
2answers
2k 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 ...
8
votes
2answers
4k views

Do different brands of the same oil really make a difference?

I've found several other questions on here that answer, "what's different between synthetic oil and regular oil?" or "Can I use X oil in Y car?", or similar, but nothing that quite answers my ...
7
votes
4answers
3k 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 ...
7
votes
2answers
8k 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 ...
7
votes
3answers
32k 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...
7
votes
2answers
68 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? ...
7
votes
5answers
251 views

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

Considering that the car recommend Mobil 1 Synthetic oil as per the logo on the oil cap, how can I be sure that the garage that did the oil change poured the recommended oil and not another low cost ...
7
votes
3answers
314 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 ...
7
votes
4answers
104 views

2002 Ford F350 Superduty 7.3L Turbo diesel using a quart of oil every 43 miles

This Diesel engine has been rebuilt and it didn't use any oil till the HPOP went out. I replaced the oil pump and then I noticed my turbo when going up a hill and the Turbo would sound like a sneeze ...
7
votes
3answers
298 views

Will I be okay running thinner oil with a minor oil leak on an older car?

Recently when I had some work done I was shown a minor leak, I believe he told me it was the oil pan. It doesn't drip out onto the ground, but if you look closely you can see condensed oil drops on ...
6
votes
2answers
23k 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 ...
6
votes
3answers
2k views

What kind of engine oil should one use in a diesel?

I got an 1987 Toyota Land Cruiser with a 2H diesel engine. I never changed oil on a diesel engine prior to this truck, so I'm a little confused. Toyota Factory Shop Manual recommend API CC oil type, ...
6
votes
3answers
12k views

How do I find a vacuum leak? I'd highly prefer not to use a carb cleaner spray

The car is a 1998 Oldsmobile Intrigue with 3.8L V6 engine (3800 Series). I've been doing my research and due diligence, but please understand I'm very inexperienced with automobiles. I went to ...
6
votes
2answers
390 views

Oil pressure question

I am driving a 1995 Bonneville and, lately, whenever I am idle, at a stoplight for example, my oil pressure drops and my check engine light comes on. Any ideas on why this could be happening?
6
votes
2answers
238 views

Do I really need to care if my car burns oil?

My car, a 97 Mazda 323, burns about a liter of oil per 1000 kilometers, mostly start and stop city driving. Sometimes I see a puff on start-up and sometimes I see smoke while accelerating, but it's ...
6
votes
1answer
6k views

How does low oil level cause misfires or VTEC malfunctions?

So a few days ago my 2003 Honda Civic EX started misfiring while accelerating, especially with the A/C turned on, making popping noises, and then yesterday got a P1259 "VTEC system malfunction code". ...
6
votes
3answers
267 views

Car stored for 6 months shows low oil level after 300 miles

Just bought a car from a BMW dealer and the guy told me it was sitting for almost 6 months before I came to purchase it. When I left the dealership the oil was above the min mark showing green. Drove ...
5
votes
2answers
202 views

What are all the different types of fluid in a car and a short summary of their use?

A fluid is defined as anything that flows, hence for our purposes a gas or a liquid. I know that there is fuel, engine oil, engine coolant and brake fluid. Also air is normally taken in through a ...
5
votes
2answers
6k 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 ...
5
votes
2answers
5k views

Oil leak when parked on steep incline

The other day I parked my car, and came back a couple of hours later to see a massive oil puddle under my 1994 Corolla. This was the only time I had ever noticed that much of a leak, and I realized it ...
5
votes
1answer
58 views

What exactly is meant by the phrase “plugging in your engine”?

I have found a relevant quote from here that might be related: Plugged-in engines are already half-warmed when started. Fuel consumption is thus reduced by an average of 15 per cent over the first ...
5
votes
4answers
9k views

Grinding sound during cold start?

I have a 2009 Honda Accord. Over the past several months, I've noticed a grinding sound immediately after cold-starting the engine. It only lasts for a fraction of a second, doesn't continue once ...
5
votes
2answers
791 views

Cadillac CTS 2007 3.6 oil consumption

3 months ago I bought Cadillac CTS 2007 3.6 with 31k miles, next day I went to local garage and changed the oil, filters, etc. I have driven 7k miles since and when driving last week car started ...
5
votes
2answers
133 views

How exactly does an increase in engine temperature cause a car to breakdown?

I have an engine temperature gauge on the dashboard of my car (as most people do), but if for some reason the engine temperature is caused to increase (due to a lack of cooling or what have you), the ...
5
votes
2answers
332 views

How to clean engine when oil is contaminated with metal shards?

During a recent oil change Istripped the oil pan bolt. It took a bit of trial and error for me to realize the stripped hole was a 14mm 1.25 thread so I got a tap and rethread it to 14mm 1.5 thread ...
5
votes
1answer
75 views

What exactly is meant by “engine coolant”?

I know that engine coolant is a fluid in the engine used to dissipate heat spots and keep the engine cool in general as the moving parts generate heat. In this context, I would call the oil an "engine ...
5
votes
1answer
72 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 ...
5
votes
2answers
898 views

What do the numbers on motor oil specifications mean?

What do the numbers and letters in a motor oil specification mean? For example: 0w-30 5w-40 10w-20 Which values are better? Also, sometimes there are additional letters and numbers ...
5
votes
4answers
3k views

Add 2 stroke oil to a 4 stroke petrol engine during burn-in period

I'm planning to get a new petrol (gasoline) car soon. A friend of mine, who worked as a motorbike mechanic when he was young, told me he puts a small quantity (125 ml / 4 oz) of 2 stroke oil in the ...