Oil consumption

[Blaise]

In reading the recent for sale posting on the 530i, I noticed the seller's comment about his car's oil consumption.

He listed that it takes about a quart every 500 miles. That is about what my car takes. To me, this is not acceptable.

So, is this normal for these cars?

Is it possible to pin point where the issue is and fix it?

My car does not leak oil onto the ground, when parked.

I can do a compression test, or a leak down test.

I have heard that it could be blow by (rings) or valve guide seals.

Without going through a full motor rebuild, I would like to know what can be done to address this.

[T.Hanson]

Your last sentence is the answer. Just drive it. You can buy a whole bunch of oil for the price of any mechanical remedies.

For drill, if the engine had reasonably prompt oil changes and never overheated, the M30 bottom ends go 200,000 and still have the cross hatching in the cylinders. Heads usually go 60,000, except for the plastic valve seals which are there to drive perfectionists crazy.

You can chase oil leaks from the front covers, valve cover gasket, oil pan, but all require major dis-assembly to access, clean, install new gaskets.

Creamy, foamy oil on the dipstick is from coolant leaking, puff on start up is usually valves leaking, plumes on hard acceleration is usually rings, pistons.

Some may have sauces they like: Marvel Mystery oil, automatic transmission fluid or Sea Foam rituals before an oil change. I'm a cynic on that stuff.

You want like new, haul off and build a 3.5 all polished and fun.

[GripGreg]

Ted, aka T.Hanson has the right idea, usually does. If you car doesn't leave a piddle of oil overnight, it's more than likely the valve guides not allowing the valves to seat properly. Add your oil & enjoy the ride. If the oil gets too dark to see the dipstick, I change the oil & filter.

[DEMIURGE]

Without going through a full motor rebuild, I would like to know what can be done to address this.

I can tell what is happened with my e12 after a full motor rebuild.
I use a semi-synthetic 15W40 oil for the initial 1100 km (about 700 miles) - just for "drive-in". Then the engine was flushed. It is a good idea to use a magnetic flush cap in the oil pan - like in Getrag transmissions. Of course - we have oil filters, but this cap will help catching some magnetic particles. After the flushing I reinstall a new oil filter, check the rocker arms clearance (readjust some of them), check the tightness of the head to block bolts for the last time.
I have thinked a lot, before I've decided what engine oil to buy. This was fully synthetic Silvania Racing 10W60 (stock used for Maserati). I know that M30 is not a race engine, but fully synthetic oil can only help. The first thing, I've noticed - the engine temperature decrease a little in heavy loads, comparing the old semisynthetic oil. The second thing was - much easier starter spinning at cold winter days (compare to the same battery, older with one year) and the third thing - surprisingly - no oil consumption - for the last near 4000 km!!!

You want like new, haul off and build a 3.5 all polished and fun.

Maybe I have misunderstood something (I'm sorry if this is so), you are speaking of all polished, but not for the cylinder walls - is this right?

[Blaise]

Good thoughts, thank you.

I will have my motor out of the car soon, so was wondering if there are some things that could be addressed easily then.

Timing chain tensioner?

[T.Hanson]

I meant polished, meaning generally shiny looking. No reference to the technical aspects of porting, polishing, etc.

Using Google search (specific to this site, listed) is good for expanding answers to questions. Unfortunately it uses search words that depend on subject titles, that folks sometimes don't clearly enter. Brake pad choices, not, " I can't stop!"

Searching, reading the archives takes time but it's the equivalent of a master tech degree in e12 mechanics. Many more experts had these cars ten, fifteen years ago. That's the rub. Time is wearing out the cars, using up the factory parts, depleting the cadre of screwballs who think they're neat.

To review, T is for Tom, Thomas if issuing a subpoena. This has always been a very civil tech site to not make me have to think up a handle, or whatever cool web guys have. Ted is good though, if you are one.

All I am is against car payments and modular parts that only shops can install for two grand, to make the turn signals work again. If you are reading this, you can read the directions, here or in a book and do everything I've done. Get the tools, get stubborn, patient, and go for it.

[Mike W.]

530's didn't hold up as well, they ran hotter and BMW improved the metalurgy as the years went on. But they still did ok or better. You can't really tell without getting into it, but the odds are you just need valve guide seals. I took an even earlier M30, a 2800 in a Bav, from a quart every 700 miles or so to not having to add any between 4K changes just by doing the valve guide seals. That is where heavy oil consumption usually comes from. Of course, if you would still have the original valve guides that itself is a problem as I don't think that style seal is still available. They changed guides in 79 so they used a different seal (non interchangable) so it's possible the only way to replace the VG seals would be to replace the guides first. At that point you are either looking at a head rebuild, not cheap, or a later head and gamble with it, though the odds aren't too bad. In a strict economic sense it doesn't make sense, but there is value in not polluting by burning oil and satisfaction in having an engine that doesn't use oil. Not to mention many an early engine threw a rod due to being run low on oil due to oil consumption.

[Blaise]

I meant polished, meaning generally shiny looking. No reference to the technical aspects of porting, polishing, etc.

Using Google search (specific to this site, listed) is good for expanding answers to questions. Unfortunately it uses search words that depend on subject titles, that folks sometimes don't clearly enter. Brake pad choices, not, " I can't stop!"

Searching, reading the archives takes time but it's the equivalent of a master tech degree in e12 mechanics. Many more experts had these cars ten, fifteen years ago. That's the rub. Time is wearing out the cars, using up the factory parts, depleting the cadre of screwballs who think they're neat.

To review, T is for Tom, Thomas if issuing a subpoena. This has always been a very civil tech site to not make me have to think up a handle, or whatever cool web guys have. Ted is good though, if you are one.

All I am is against car payments and modular parts that only shops can install for two grand, to make the turn signals work again. If you are reading this, you can read the directions, here or in a book and do everything I've done. Get the tools, get stubborn, patient, and go for it.

Thanks Ted. Being a part of a community like this sure makes it less overwhelming and more fun.

[GripGreg]

So sorry, Tom. I guess it's because of Ted Danson. No subpoenas though.
Hey, an earthquake in Long Beach!! It lasted about four seconds & the cats disappeared.
I totally agree about the car payments & modular replacements.

[Blaise]

530's didn't hold up as well, they ran hotter and BMW improved the metalurgy as the years went on. But they still did ok or better. You can't really tell without getting into it, but the odds are you just need valve guide seals. I took an even earlier M30, a 2800 in a Bav, from a quart every 700 miles or so to not having to add any between 4K changes just by doing the valve guide seals. That is where heavy oil consumption usually comes from. Of course, if you would still have the original valve guides that itself is a problem as I don't think that style seal is still available. They changed guides in 79 so they used a different seal (non interchangable) so it's possible the only way to replace the VG seals would be to replace the guides first. At that point you are either looking at a head rebuild, not cheap, or a later head and gamble with it, though the odds aren't too bad. In a strict economic sense it doesn't make sense, but there is value in not polluting by burning oil and satisfaction in having an engine that doesn't use oil. Not to mention many an early engine threw a rod due to being run low on oil due to oil consumption.

I will probably use the 1980 528i motor, so it will have the later head. I will look into refreshing the head, as the motor will be out of the car and access easy. I agree that it does not make sense to invest too much in such a standard motor. My issue with oil consumption is not so much about the cost of oil, but the consequence if I forget to top it off and let it run low.