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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32
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9answers
43k 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 ...
26
votes
4answers
52k 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
8k 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 ...
20
votes
7answers
81k 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. ...
19
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 ...
19
votes
3answers
6k 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?
18
votes
4answers
207k 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 ...
18
votes
6answers
32k 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. ...
17
votes
4answers
2k 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 ...
16
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 ...
16
votes
3answers
1k 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 ...
16
votes
3answers
8k 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 ...
13
votes
2answers
179 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 ...
12
votes
3answers
8k 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 ...
12
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 ...
12
votes
7answers
16k 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
370 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
5answers
922 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 ...
10
votes
3answers
2k 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 ...
10
votes
4answers
41k 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 ...
10
votes
4answers
40k 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 ...
10
votes
3answers
286k 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 ...
9
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 ...
9
votes
6answers
27k 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. ...
9
votes
2answers
3k 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
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
164 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.
8
votes
3answers
44k 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...
8
votes
2answers
11k 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 ...
8
votes
2answers
322 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.
8
votes
1answer
57 views

Effects of sunlight on engine oil

I have a 5 litre bottle of oil out back that I was going to top my car up with when I realised it's been out on the sun for about a month, the bottle is opaque and does not let sunlight through (apart ...
8
votes
2answers
5k 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
11k 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 ...
7
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, ...
7
votes
2answers
383 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 ...
7
votes
2answers
238 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
295 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
2answers
433 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?
7
votes
3answers
99 views

Excessively over filled motor oil. Ran for a few seconds until smoke came out. Now my car won't start

So last night me and a friend changed the oil on my 2005 Chevy aveo. The only problem was that what we were draining was the transmission fluid and long story short we ended up adding about 6 litres ...
7
votes
2answers
65 views

How do I remove oil sludge from an installed engine?

What's the preferred, non-chemical/non-additive method for removing oil sludge from an engine that's still installed in the vehicle? I'll have the head and oil pan removed. How do I clean out the ...
7
votes
1answer
124 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 ...
7
votes
4answers
160 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
334 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 ...
7
votes
1answer
354 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 ...
6
votes
4answers
303 views

Do air filters purifty air better with age?

I have been reading in a few places that air filters get better with age, is this true? And how much better? Would it have any effect on quality of the oil or make oil dirty faster? Or is there ...
6
votes
4answers
871 views

High oil warning in Mercedes B class diesel

I have a Mercedes B class diesel 2010. I have had it since August 2015 from a dealer who serviced it, and everything is running fine. I have noticed a warning saying drop oil level, so I measured the ...
6
votes
2answers
26k 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
16k 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
1answer
43 views

Electric Oil pump

Modern cars have lots of electric stuff like fans etc.The oil pump does not need to much energy to spin so making it electric would not be a nightmare on a car with an orthodox electrical system .The ...
6
votes
1answer
65 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 ...