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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4answers
56k 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 ...
35
votes
9answers
86k 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 ...
10
votes
5answers
950 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 ...
15
votes
4answers
4k 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 ...
8
votes
3answers
55k 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...
15
votes
4answers
318k 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 ...
7
votes
3answers
13k 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 ...
6
votes
2answers
28k 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-...
19
votes
6answers
33k 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. ...
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 ...
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?
21
votes
7answers
92k 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. ...
12
votes
3answers
9k 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 ...
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 ...
9
votes
5answers
184 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
2answers
13k 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 ...
6
votes
2answers
544 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 ...
4
votes
1answer
167 views

Quick Oil Change place overfilled my BMW Z3

Just got this car, a BMW Z3 3.0 from a Tampa dealer and have not even had it 10 days and Check Engine Light came on. I wanted to get the oil changed to full synthetic just in case it wasn't and ...
4
votes
1answer
179 views

I've got oil in my coolant but no coolant in the oil - Ford Triton V10 Motorhome

I have a Triton v10 engine in my vehicle I have oil in my coolant but no coolant in the oil. What could be the problem?
2
votes
2answers
5k views

Can I use EP 80W/90 oil instead of EP90 oil?

I have a Belle MiniMix 150 110V Electric Cement Mixer the documentation says to use a EP90 oil in the gear box, but these days it seems that most outlets only sells EP80/90 oil. What is the ...
1
vote
1answer
521 views

Does one have to change ester-based fully synthetic oils?

They say that ester-based oils are used in jet-engines, where the oil is sealed, and it never has to be changed. If I use an ester-based oil as the lubricant for my Jetta 2.5L petrol, such as the ...
21
votes
4answers
230k 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 ...
13
votes
2answers
207 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 ...
11
votes
4answers
4k 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 ...
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 question....
8
votes
2answers
458 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.
7
votes
2answers
679 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
1answer
92 views

Are there any vehicle engines that don't have a mechanical oil pump?

I my answer to How to move car a small distance without tow dolly I suggested putting a manual transmission vehicle in 3rd gear while towing with a rope or strap to apply back pressure and help keep ...
3
votes
2answers
3k views

accidentally placed oil in the coolant reservoir in a BMW 325i. How do I fix it and what is the cost?

I accidentally added oil to my coolant reservoir. I have a BMW 325i. The oil light came on and I figured my oil may be low. When the oil was added the oil light warning went off. However, the ...
2
votes
3answers
4k views

Can camshaft seal leaking hurt timing belt and cause sudden engine breakdown while driving? - Volvo XC90

Volvo service told me that the camshaft seal of my Volvo XC90 needs to be replaced for $1000. I see no oil on the timing belt, its dry. It just has some black dust. If there is real leak, can it ...
2
votes
2answers
1k views

Grey smoke when idling 1999 GMC Suburban, coolant system pressure loss

The most recent update is at the bottom. This looks interesting. The Smoke I'm confident the smoke is from burning oil. It's slightly blue, absolutely not white. If the engine is warm and I am ...
1
vote
2answers
724 views

Cream on oil cap? How to maintain a car that drives only short distances in Nordic environment?

My friend needs a car for night-time driving for distances about 15 km to-and-fro for his work. I read that short distances may be problematic to cars because the engine does not get hot enough -- ...
1
vote
1answer
291 views

very bad gas mileage in a brand new german car

I bought a brand new 2008 Jetta SE (2.5L petrol engine, automatic transmission, 21mpg city, 29mpg highway) in May 2008, which had under 200 miles on it. I immediately within a week drove it from ...