Why change your oil?

[GH85Carrera]

Umm..Need Advice...VANOS job in progress after 40k on an oil change - Bimmerforums - The Ultimate BMW Forum

This is why I change the oil in my cars often.

[Rick V]

I like people like that, I make very good money getting them back on the road.
Bring forth those that spring from the shallow end of the gene pool

[M.D. Holloway]

I'm going to use those pics in a training seminar. I can give many many reasons why to change oil but I will also add that some folks do change it too often ( which is a waste of monet and really provides no benefit) while others change it too late. Every engine is different and the only way to really know when to change oil is to test it. Costs about $10 to $20 per test depending on the lab. Its cheap and effective at not only helping determine change intervals but also as a diagnostic tool to shed light on emerging problems before they become a costly headache.

[legion]

Wow. That is sick.

Was he noticing a "slight loss of power"?

[onewhippedpuppy]

Wow. Just wow. Even my wife knows to change the oil every 3k or so.

[GH85Carrera]

I tested my oil at every change for over 100,000 miles. I could see the silicone start to go up and drop right back after I changed the air filter. It has been close to 100,000 miles since my last test. I need to do that on the next change.

One thing for sure is I can check the dipstick 1,000 miles after a change and the oil is still clear with 278,000 miles on the engine. My 911 is the same way only at 130,000 miles.

[Joeaksa]

Idiots. What the rest of the engine is like is a good question.

Its things like this that scare me about buying anything used.

[M.D. Holloway]

That is as bad as I have ever seen it but it does say something for the robustness of a BMW engine! Even with a crankcase full of 'grease' the darn thing kept going.

Also keep in mind, just cuz you do not see oil darkened on the dipstick doesn't mean there is not bad chemistry going on in the engine.

[syncroid]

I worked on a car like that once several years ago. It was an Audi 5000S. The customer stated that it had been 90K since the last oil service. The car was warm when I started working on it. I pulled the drain plug and nothing came out. I looked in the drain hole and saw it was blocked with goo. I poked at it with my pocket screw driver expecting a torrent of hot oil to come rushing out. Still nothing. What we ended up doing was adding a couple of quarts of ATF and taking the car out for a spirited german tune up and tried to drain it again. Some success. Long story short, it took three or four treatments of ATF before we got a good drain on that motor. I couldn't believe the motor was still functioning like that.

[s_morrison57]

The person responsible should be slapped more than once, expensive car wrecked. Just goes to show you, just cause you have money doesn't mean you have brains

[red-beard]

I guess I need to think about regreasing my jeep

[Bill Douglas]

I'm not a mechanic, but I'd opt for an engine stripdown and a large scrubbing brush. Probably fresh oil would move that sludge and block oil pipes.

[Joeaksa]

Originally Posted by Bill Douglas

I'm not a mechanic, but I'd opt for an engine stripdown and a large scrubbing brush. Probably fresh oil would move that sludge and block oil pipes.

Bill,

You are very optimistic! I would pull the pan, pull a main and rod bearing cap that is far away from the oil pump and take a look. If it did not look great its time for an overhaul.

All of a sudden not changing oil would be very expensive.

Joe A

[sammyg2]

I NEVER change my oil after 3000 miles. That's just throwing money away. That is the result of an advertising scam by jiffy lube and the like.

My truck's owner's manual recommends every 7500, that seems about right.

BTW, I make a living trying to make machinery run longer between overhauls so I've done the research.
Where I work, most of our centrifugal pumps (almost 1000 of them) don't even have oil in the sump. We use a very fine mist of oil injected into the bearing housings, looks like a very slight wisp of smoke and that's all it takes.

[sammyg2]

I used to work with an Australian guy who bought a new dodge Dakota truck. he drove it for almost 50,000 miles before he traded it in on something bigger. He told me that the whole time he owned it, he never once lifted to hood. Never saw the engine, never checked the oil, never checked the tire pressures, never had any service done at all. The only thing he ever did was put gas in it and drive it.
I asked him why, he said because he hated that truck and wanted to kill it. Amazing.

[Schumi]

I'm pretty sure that Porsche recommends oil changes with Mobil 1 Synthetic every 7500 miles nowdays.

I think synthetic oil can hold up just fine for 7500 miles... but my real concern is the other things that I do when I change the oil- change the filter and check the magnet on the plug. While the oil may be fine, it's imperative that the filter is clear and theres no flake in the pan. Sometimes you can catch things before destroying a crank if there is an oil problem (not that I ever have had one).

My friend had an Integra that shat crank bearings after loosing a massive amount of oil somehow. This being a car he bought years ago for 75$, he simply flushed the pan and threw in some 70W tractor oil and kept going. Since then he's driven it to Omaha and back to MO with no problems, even though he literally fished pieces of bearings out of the pan.

Crazy stuff, those honda engines..

[gprsh924]

We change the oil in the 525 when the onboard computer tells us to

[onewhippedpuppy]

Personally I go 5k with full synthetic. I could probably go more, but why take a risk? Oil is cheaper than a motor.

[serge944]

This story reminds me of my mom's first car. 30k miles on a single oil change later - the poor Buick Skyhawk was dead.

I'm on the 5k oil change plan too. Not too long ago, Honda recommended 15k on a synthetic oil change. Long story short, some engines were damaged because those cars were used in extremely hot climates and driven hard. There's no right answer - you be the judge.

[aigel]

40k is crazy - 3 k too, generally.

I run oil analysis on all my vehicles to determine what's necessary. 5k is a good rule of thumb on a fuel injected engine with dino oil. Diesels with lots of oil volume and serious diesel oil in it can go 10k +. My 993 gets annual changes - rarely get over 5k / year on the synthetic. If I would run it more, I'd change at 15k if the oil analysis supported it.

Oil analysis is cheap and a lot less messy than changing your oil too often ...

George