ANOTHER oil change question

[new128]

This type thread is what keeps me coming back to this forum. It proves that comedy isn't dead. Someone asks an innocent oil change question. And here come the two sides. The 15,000 mile change is going to ruin your engine camp and the 5,000 mile change is wasting your time and money camp. These two camps are never going to go away, so anyone looking for advice should understand this.

I'm sure you have all seen the old cars that have one primed fender, not washed in months, one hubcap missing, etc. These cars are purchased for a couple hundred bucks. They probababy never change their oil and when the engine stops, they simply buy another cheap car.

But, that's not us. Usually, the oil change question is about a new or fairly new car. Yes, I'm sure the "1994 740i that had the engine replaced at 99K miles" is not a lie. But, can it be proved that this was an oil-change-interval issue? I challenge anyone to show me any statistics that say this is normal. In a modern car, internal engine failure because of oil change interval should never happen - whether you change at 5,000 or 15,000 miles - only if you never change it. The most serious effect you might see with 15,000 changes is increased oil consumption - maybe. And adding a quart between oil changes is a lot cheaper than changing oil/filter every 5,000 miles.

Since joining this forum, I have seen this topic over and over and it will go on forever, with the 5,000 vs 15,000 opinions. So, change your oil anytime you want. But, don't try to convince people that your way is the only way, unless you can back up your opinion with statistical proof that 15,000 mile oil changes cause engine failure.

And I also question these "oil analysis" posters. What is the analysis telling you - that you aren't changing your oil often enough? If you are seeing anything in the oil, isn't that telling you your filter isn't working correctly? The filter design is such, that anything getting through it is probably not hurting your engine. If it is, then you have a problem more severe than a change interval. Since having your oil analyzed is somewhat extreme, I would assume it is only being done by the 5,000 mile guys. Do you ever do anything about an analysis?

But, whatever makes you comfortable is the correct way to go.

But, even the 5,000 mile changers should agree that 15,000 mile changes should easily get you to 100,000 miles - which is the max for the majority of "new-car" drivers.

[BMW86]

Originally Posted by ScotchAndCigar

This is simply untrue. The only "argument" against is an unsubstantiated one by owners such as yourself. The other side of the issue is the carmaker's specification, backed by the company and supported by a decade of real-world results.

Yes, and many people feel the same about buying Advil instead of generic ibuprofen, but that doesn't mean there's any reasoning behind it.

Frankly, considering that people were doing 7500 mi oil changes decades ago, and now with modern engine manufacturing, Nikasil-lined cylinders, and full synthetic oil, your recommendation of shorter OCIs is comical.

Again, it's your car - do what pleases you. If changing the oil every 5K increases your enthusiast connection to your car, great. Just don't claim that what your doing is providing any extension to your engine's life. BMW feels that their maintenance intervals will provide satisfactory lubrication for the life of the engine. In other words, the engine will not fail due to lube issues. As with many things in life, sometimes there is "adequate" and "not adequate". Not everything is on a continuous sliding scale of good, better, best.

Like I said, I guess it comes down to personal preference and how you feel about it. I know of people that actually stick to the scheduled maintenance and they have no problems whatsoever.

By the way, I noticed you drive a 128i, not a 135i. If I were in your situation I would probably feel a bit more relaxed about changing the oil as frequently on a naturally aspirate engine, although I probably would change it more often anyway. However, for those of us that have forced induction turbo engines pushing upwards of 350whp, it makes the decision a bit easier, especially if we know the cars being driven hard. I'm not saying the car will break down without extra oil changes, I just prefer to keep my car in the best condition I can.

[One_M]

Well said and stated for the above two posts.

Personally, I think it can't hurt to do the oil a little more often than needed, and to be honest, If you have the money to buy a BMW you shouldnt ever be short on money for maintainence.

Oil spectrum analysis is quite involved and you'd be opening a bigger can of worms by going down that path. I think It would be fair to say that Engineers at BMW have not overlooked the service intervals and that you could trust their periods, however, like I said, changing a little more often surely is an extra precaution.One thing to note though, once a filter is blocked it can be prone to building pressure and sometimes discharging particulates caught up in the filter material, or even breaking down the material itself. It is interesting to note though, that it is often the finer materials that do the most damage, very fine material has an almost lapping effect. So the most important design precautions may well be out of your hands before you even purchase the car.I guess also the chemical compositon of the country the car is in also has merit. Despite technology, it wasnt until the late 90's BMW ditched Nickel-Silicone carbide and went with AluSil because of the detriment caused by high levels of Sulphur in the petrol. I guess this proves that the best precaution regular maintanence can offer can sometimes still be overshadowed by larger issues...never hurts though.

Plenty to consider.

[ScotchAndCigar]

Yes, I agree that if I had a turbo engine, especially one with aftermarket tweaks, I'd keep a closer eye on the oil.

But I find it interesting, that my comment about changing the oil frequently increasing the risk of a screw-up, has been borne out in an adjacent thread http://www.1addicts.com/forums/showt...php?t=504621.;)

[JimD]

I change my oil myself to avoid issues. If you take it somewhere, they can mess up too. My mom had to buy a new car after a Walmart oil change. It ran a day or two without oil so of course they denied liability. I also change it myself because it takes less time than taking it somewhere.

The first thing that happens when you don't change your oil often enough is you get metal to metal contact in a babbit bearing. The camshaft, the connecting rods, and the crankshaft bearings are all babbit. This is a soft lead based alloy. If you don't keep oil between the bearing and the crankshaft, connecting rod, or camshaft and the bearing the bearing is damaged. One of the things they look for in an oil analysis is evidence this has happened. A tiny amount of touching will not instantly fail the engine but it is equivalent to a lot of miles with no touching. There is always a little on startup but if the oil is good, it should not happen once you have oil flow established.

If you get enough contact with the babbit, the bearing goes away and the engine can have a catastrophic failure. Many do not, however. One of the Saturday morning TV shows is building up an old Camaro. Last Saturday they tore down the engine and found a rod bearing missing. It broke a piston and damaged a cylinder but they think they can sleeve the block and use it. The engine was probably running when it went to the junk yard. Wonder how long they let that oil go?

Many many years ago I had a VW based dune buggy. I got to buying hop-up parts from a small place that also did engine repairs. They had a bug in there one time when I was there and were laughing about the amount of money they made off its owner. She apparently just ran engines to failure and then had them changed out. They would go a year or two, maybe three.

I'm not sure you're hurting your engine following BMW's guidance. But I like a little more frequent oil changes for my cars. The difference is unlikely to show up in the first 100,000 miles but I think it makes a difference. The hotter the engine runs, the thinner the oil gets and the more important it is that it be in good shape.

Jim

[new128]

BTW - I don't put a lot of miles on my car, so I am not in the 5,000 or 15,000 mile camp. I am in the once a year camp (I don't put on more than 10,000). And for years I have been following a practice of oil/filter once a year and filter half-way in between (which usually means add a quart). With the 128 filter being so easy to change - I will definitely follow this practice going forward.

[One_M]

Originally Posted by JimD

There is always a little on startup but if the oil is good, it should not happen once you have oil flow established.

Which is why I hate starting the car simply to move it a few metres and turn it off again.

[Dackelone]

Originally Posted by One_M

Which is why I hate starting the car simply to move it a few metres and turn it off again.

What is that saying... less then 20 secs or longer than 20 minutes.

[One_M]

Originally Posted by Dackelone

What is that saying... less then 20 secs or longer than 20 minutes.

Haha, are you asking if I sit in traffic?
No, I was refering to starting it up cold and moving it off the driveway etc

[new128]

From JimD "...the bearing is damaged. One of the things they look for in an oil analysis is evidence this has happened...".
And what are you going to do about it? Tear the engine apart because an oil analysis says this? I could understand if you suspected that you were having such a problem and the oil analysis confirmed it (on a high mileage car), but I have seen people on this forum talk about having an oil analysis done on their new car.
My point is; an oil analysis seems more like just another tool, when you suspect a problem with your high mileage car, not just for the hell of it? Is anyone going to start tearing apart their engine just because of an oil anaylysis? Are they going to change their oil frequency from 5,000 to 3,000 because of an oil analysis?

[JimD]

If I saw too much lead or tin in an oil analysis I would change my oil more frequently. That is the point of doing an oil analysis to me. It tells you if what you are doing is working.

With respect to how long could you have touching on a cold start I think it is under a second. Certainly it is no more than a few seconds. As soon as there is a little pressure the surfaces should not touch. If the engine ran recently, then there may still be enough oil on the surfaces that there is still not touching of metal to metal. But that depends some on the condition of the oil. Relatively fresh oil will cling to the metal better - it resists being moved off the metal. Old oil that has lost some of its additives is more easy displaced and is more likely to permit contact or to permit it to occur longer. I've also seen speculation that using too high a weight oil slows down getting flow to all the surfaces so it could permit metal to metal to occur a little longer (still measured in seconds at most). You would be worried about the cold viscosity - the lower number. One of the advantages of synthetic is supposed to be that the additives increase the viscosity number hot. "Dino oil" has additives that reduce the cold viscosity. As the additives break down, the synthetic will stay thin cold to get the engine up to full flow quickly. The "Dino oil" will thicken cold as it gets old which makes damage at cold start more likely. Part of the oil analysis is the condition of the additives.

Jim

[One_M]

Debating wear is almost pointless, it will and has to happen.The simple discussion here is how often to change the defence mechanism for it. And I think personally if you do it a little more often, good on you, you're liberating the chance of doing less damage.

A good broad spectrum Multi-Grade oil is always a good choice.

[1on135_deal]

just got my 135 and had to to top it off at 3,500 miles rofl it said please add 1 quart oil is low.