Hello All

[neoacacia]

First-time BMW owner here ... I've got a '98 740i with 155k miles ... Was as far as I can tell very well taken care of. I've never owned or driven a car like this and would like any advice ya'll can offer me to help me get acclimated with this beast of a car! Cheers!

[SilverIris]

Welcome. The first few things I can think of off the top of my head are to bookmark these resources:

Parts Catalogs: https://www.realoem.com/
Service Information & Wiring Diagrams: https://www.newtis.info/
VIN/Options Decoder: https://www.mdecoder.com/
Timm's awesome E38 site: https://www.meeknet.co.uk/E38/
Older site, but still useful: http://www.e38.org/

Driving an E38 for the first time is an epiphany, you finally realize what you were missing all along. "This is how a car should be" were my exact words when bringing my 740I home

There are a few things almost every E38 owner will encounter, the most intimidating one being transmission fluid/filter change. To be completely honest, having never done so on ANY car before, doing a fluid/filter change on my 750IL hasn't been too bad. I'm doing the final fill right now...

[neoacacia]

Welcome. The first few things I can think of off the top of my head are to bookmark these resources:

Parts Catalogs: https://www.realoem.com/
Service Information & Wiring Diagrams: https://www.newtis.info/
VIN/Options Decoder: https://www.mdecoder.com/
Timm's awesome E38 site: https://www.meeknet.co.uk/E38/
Older site, but still useful: http://www.e38.org/

Driving an E38 for the first time is an epiphany, you finally realize what you were missing all along. "This is how a car should be" were my exact words when bringing my 740I home

There are a few things almost every E38 owner will encounter, the most intimidating one being transmission fluid/filter change. To be completely honest, having never done so on ANY car before, doing a fluid/filter change on my 750IL hasn't been too bad. I'm doing the final fill right now...

Thank you! I'm very inexperienced with DIY car maintenance & repairs but I'm hoping to start seriously upping my skills & knowledge with this car.

[SilverIris]

That's the most important part of owning a 7-series, the desire to learn. Since these cars tend to intimidate the average person, Hondaboi-type butchery tends to be rare. Even shops tend to shy away from touching them too, meaning that the most likely scenario is that neglect is the most common issue.

One thing to help get your feet wet is to just do an oil change. Compared to every other car I've every turned a wrench on, my E38 was the most relaxing and non-dramatic one in this area.

The worst offender: a 1999 Honda Accord whose last oil change was at an Acura dealership in the Columbus, OH area in 2013. Drain plug was torqued to 80ft.lbs, crush washer was reshaped and nearly "merged" with the surface under the hex head. Took careful prying, some vise grips and patience to extract it from the undamaged plug. The filter was collapsing from overtorque (big surprise...). Ended up punching a big screwdriver through it to bust it loose. Now you know why I'm not a mechanic...

There's a lot of discussion about what oil to use, what meets the LL-01 specifications, etc, but I think conventional wisdom wins the day on the subject. LL-01 is BMW saying to not touch it for 10 or 15k miles. They said something very similar about our transmission fluid/filter too (Lifetime fill), which they later backpedaled on when proven wrong. Probably something you'll be facing in the near future too. It looks like you have a 5HP24 (A5S-440Z) transmission, but doublecheck the pan's shape. 5HP24 is square, 5HP30 is roughly pentagon-shaped. I'm writing a guide that covers both transmissions' fluid/filter change for situations like this.

Anyway, back to Oil. Generally speaking, any 5w-30 full synthetic is fine for a normal 3000 mile oil change. Same thing with a filter, there's no benefit to spending more on a filter if it is being replaced in 3000 or less miles. I use Walmart's Supertech 5w-30 full synthetic oil in my 740I and Ultra-Power filters (re-labeled Super Auto filters, $2.64 each!) from Rock Auto. Depending on how your car was cared for before you got it, shorter-than-recommended oil change intervals are a good way to flush out nasties from previous owners' bad ideas.

[282hp]

That's the most important part of owning a 7-series, the desire to learn. Since these cars tend to intimidate the average person, Hondaboi-type butchery tends to be rare. Even shops tend to shy away from touching them too, meaning that the most likely scenario is that neglect is the most common issue.

One thing to help get your feet wet is to just do an oil change. Compared to every other car I've every turned a wrench on, my E38 was the most relaxing and non-dramatic one in this area.

The worst offender: a 1999 Honda Accord whose last oil change was at an Acura dealership in the Columbus, OH area in 2013. Drain plug was torqued to 80ft.lbs, crush washer was reshaped and nearly "merged" with the surface under the hex head. Took careful prying, some vise grips and patience to extract it from the undamaged plug. The filter was collapsing from overtorque (big surprise...). Ended up punching a big screwdriver through it to bust it loose. Now you know why I'm not a mechanic...

There's a lot of discussion about what oil to use, what meets the LL-01 specifications, etc, but I think conventional wisdom wins the day on the subject. LL-01 is BMW saying to not touch it for 10 or 15k miles. They said something very similar about our transmission fluid/filter too (Lifetime fill), which they later backpedaled on when proven wrong. Probably something you'll be facing in the near future too. It looks like you have a 5HP24 (A5S-440Z) transmission, but doublecheck the pan's shape. 5HP24 is square, 5HP30 is roughly pentagon-shaped. I'm writing a guide that covers both transmissions' fluid/filter change for situations like this.

Anyway, back to Oil. Generally speaking, any 5w-30 full synthetic is fine for a normal 3000 mile oil change. Same thing with a filter, there's no benefit to spending more on a filter if it is being replaced in 3000 or less miles. I use Walmart's Supertech 5w-30 full synthetic oil in my 740I and Ultra-Power filters (re-labeled Super Auto filters, $2.64 each!) from Rock Auto. Depending on how your car was cared for before you got it, shorter-than-recommended oil change intervals are a good way to flush out nasties from previous owners' bad ideas.

This was a great post. And it leads me to a question...
Back when I got my first E38 in 2012, I read on the E38.org board that during next oil change, the oil pan should be dropped and the bolts on oil pump should be checked and tightened if needed.
When I asked my mechanic to do this, he really acted as if it were a waste of time. But I insisted, and afterwards he said the bolts were not loose.
What are you thoughts on this? Have you done this before?

[SilverIris]

No I have not done this. I don't see any harm in it, but it seems like an awful lot of time/effort to scrape off the old oil pan gasket and replace it just to check the bolts on the oil pump. In all likelihood, the last person to touch the oil pan/pump bolts was on the assembly line at the Dingolfing Plant.

Meanwhile, our transmissions often go untouched with fluid and filter from the Super NES and N64 era...

[racer2086]

This was a great post. And it leads me to a question...
Back when I got my first E38 in 2012, I read on the E38.org board that during next oil change, the oil pan should be dropped and the bolts on oil pump should be checked and tightened if needed.
When I asked my mechanic to do this, he really acted as if it were a waste of time. But I insisted, and afterwards he said the bolts were not loose.
What are you thoughts on this? Have you done this before?

This was an occasional issue with early model year E38s. The bolts would get loose and in some cases fall out into the pan. FWIW, I replaced my timing chain guides at 195k miles and the pump bolts were fine.

One benefit to dropping the oil pan in a higher mileage car is to examine the pan for any plastic parts, as that usually indicates that the timing chain guides are starting to disintegrate. That is a failure that if not caught can be catastrophic.

Lastly, it is very easy to drop the oil pan compared to other cars and the gasket is only $30. The gasket is metal with rubber impregnated, so there shouldn't be much if anything to scrape. I do skim mine with a thin coat of RTV to seal it up well, because like every BMW rubber gasket, it gets hard in not much time and seeps otherwise.

[goinstrong]

I replace the timing chain tensioner. They are not hard to do unless you let the spring loose! Keep it in its compacted size, and the removal/installation can be done in about 15 minutes. Those springs get weak, and I believe increase the odds of the plastic timing chain guides going bad. Welcome and enjoy!