High Mileage Oil Infrequently driven BMW N55.

[BMWTurboDzl]

I was reading the Pennzoil High Mileage QA and they mentioned that infrequently driven cars may benefit from a High Mileage oil as the seals are not routinely splashed with oil.

I put around 6k miles/yr in the car and it's always multi-hour highway miles when it is driven. Lately I've noticed a burning or hot oil smell from the turbo side of the engine bay which got me think it's either a hardening oil pan gasket which may have finally begun to weep or turbo oil line or an exhaust leak at the turbo* as all the usual suspects don't present themselves. HTHS is a bit of a concern but 40 grade High Mileage oils are always sold as 10w-40.

I'm at 85k miles in a 12 yr old car. Would you be tempted to switch to a 10w-40 High Mileage oil because it's driven infrequently?


*This would annoying because I always give my car time to warm up before sending it.

 

[billt460]

With 85,000 miles I would definitely switch to a High Mileage oil. Most of the High Mileage stuff is recommended on the bottle for, "Over 75,000 Miles".... So you officially fall into that bracket.

My Jeep Grand Cherokee is 11 years old, but it only has 20,000 miles. So I'm still debating.

 

[wlk]

You could also add LiquiMoly Motor Oil Saver to whatever Euro oil of your choice. Has worked very well for me over the last few years.

 

[chris719]

I saw an N55 oil pan gasket leak at 42k miles. I doubt any oil is really going to stop a BMW from leaking oil. I'd just run a good Euro oil and let it leak until you can't tolerate it and replace the offending gasket or component.

 

[edyvw]

I was reading the Pennzoil High Mileage QA and they mentioned that infrequently driven cars may benefit from a High Mileage oil as the seals are not routinely splashed with oil.

I put around 6k miles/yr in the car and it's always multi-hour highway miles when it is driven. Lately I've noticed a burning or hot oil smell from the turbo side of the engine bay which got me think it's either a hardening oil pan gasket which may have finally begun to weep or turbo oil line or an exhaust leak at the turbo* as all the usual suspects don't present themselves. HTHS is a bit of a concern but 40 grade High Mileage oils are always sold as 10w-40.

I'm at 85k miles in a 12 yr old car. Would you be tempted to switch to a 10w-40 High Mileage oil because it's driven infrequently?


*This would annoying because I always give my car time to warm up before sending it.

Absolutely not.
Just exercise car now and then.

 

[Japanese]

What oils have you used until now?

HTHS is a bit of a concern but 40 grade High Mileage oils are always sold as 10W-40.

I'm at 85k miles in a 12 yr old car. Would you be tempted to switch to a 10W-40 High Mileage oil because it's driven infrequently?

Do not run High Mileage 10W-40 or any other 10W-40. Your engine needs BWM Longlife LL-01 oil. I would recommend Mobil 1 Euro 0W-40 or Castrol Euro 0W-40 (A3/B4) oils. Those are great oils available at Walmart for like $25 a jug.

* This would annoying because I always give my car time to warm up before sending it.

How do you usually warm up your engine and for how long, before you "send it"?

 

[billt460]

All of this can't help but make you wonder. We've been to the Moon 9 times over a half a century ago. And yet today we can't seem to make oil seals and gaskets for automobiles that can hold up for 10 years of normal operation without leaking.

 

[BMWTurboDzl]

You could also add LiquiMoly Motor Oil Saver to whatever Euro oil of your choice. Has worked very well for me over the last few years.

Ya I thought about it but I read some Amazon reviews where it made the leaks worse. That being said if I indeed have a weep then it's probably not too far gone.

 

[BMWTurboDzl]

Absolutely not.
Just exercise car now and then.

I drive it every 1-2 months. I guess that's enough if it's all highway. I was really hoping to sell it earlier this year but as you know things outside ones control can change your plans.

 

[wlk]

Ya I thought about it but I read some Amazon reviews where it made the leaks worse. That being said if I indeed have a weep then it's probably not too far gone.

It probably cleaned up around a seal that was sealed up by sludge and then leaked past, but did they give it time to seal afterwards? Or did it clean a damaged seal that was sealed up by sludge and nothing w help here. There are plenty of ways to blame a seal additive when nothing but replacement is the answer. LM MOS has been talked about here a lot and more times than not helps.
But if you just want a High Mileage blended oil, I'd use 10w40 High Mileage like Maxlife, Castrol GTX High Mileage or Quaker State All Mileage. All of these have helped my vehicles with leaks and have a HTHS of >3.5, if worried about that. I'd pass on Mobil 1 High Mileage 10w40, I've never had Mobil 1 help any leak.

 

[Hohn]

All of this can't help but make you wonder. We've been to the Moon 9 times over a half a century ago. And yet today we can't seem to make oil seals and gaskets for automobiles that can hold up for 10 years of normal operation without leaking.

No, we absolutely can.

But we engineers don't get to do our best. We are required to do "good enough" almost all the time. And for the typical lessee of BMWs, good enough gets them through the first lease and then nobody cares after that.

The industry and most engineers have known how to make bombproof flange seals for a long time now. Press in place, Edge molded gaskets, etc. Viton FKM elastomers for oil, you name it.

Oil leakage is 100% of the time due to someone deciding that a leak-free, reliable design was too expensive. Cost is why we have squirt-gun FIPG seals now instead of molded elastomer seals edge molded to carriers made of premium steel or aluminum.

Even when you get an o-ring or molded seal, it will be made of cheap nitrile instead of HNBR or FKM, never mind the FFKM that is about as good as it gets.


It's the same reason Hemis and other engines shear exhaust manifold bolts: the failure is very well understood and pretty easily remedied IF you want to pay the cost of the complex bellows and v-bands required to render it bombproof for ages.

COST, NOT TECHNOLOGY OR SKILL is always the limitation.

 

[Hohn]

No, we absolutely can.

But we engineers don't get to do our best. We are required to do "good enough" almost all the time. And for the typical lessee of BMWs, good enough gets them through the first lease and then nobody cares after that.

The industry and most engineers have known how to make bombproof flange seals for a long time now. Press in place, Edge molded gaskets, etc. Viton FKM elastomers for oil, you name it.

Oil leakage is 100% of the time due to someone deciding that a leak-free, reliable design was too expensive. Cost is why we have squirt-gun FIPG seals now instead of molded elastomer seals edge molded to carriers made of premium steel or aluminum.

Even when you get an o-ring or molded seal, it will be made of cheap nitrile instead of HNBR or FKM, never mind the FFKM that is about as good as it gets.


It's the same reason Hemis and other engines shear exhaust manifold bolts: the failure is very well understood and pretty easily remedied IF you want to pay the cost of the complex bellows and v-bands required to render it bombproof for ages.

COST, NOT TECHNOLOGY OR SKILL is always the limitation.

As a followup:

The ultimate in low-cost and high performance is the humble O-ring. If you make every fluid passage round, you can machine a receiver groove in the flange and seat a premium elastomer like VITON in there and it will basically never leak in your lifetime, and because the annual production volume is so high on the common sizes, even VITON is dirt cheap.

But this has downsides that OEMs don't want to live with. For one, round passages take up more space than oval one, and space is always at a premium in a modern squish-it-as-small-as-possible engine bay.

But perhaps the bigger downside is that a completely blind o-ring sandwiched between two machined flanges gives you absolutely no warning or indication whatsoever if the o-ring is missing or cut or otherwise not installed correctly. So you have a fantastic design that is superbly reliable and cost effective-- but ONLY once you overcome the challenge of proper installation and having to somehow verify the presence and orientation.

The moment you add any kind of visible external check (like an edge molded carrier), you forfeit all the cost advantage of o-rings.


The best practice IMO for sealing usage is circular o-ring grooves cut in machined parallel faces. Then the faces are orientated horizontally. And to preserve utmost alignment of the two faces, dowel pins for precision location are used. So you have the lower face oriented horizontally, install the o-rings and the two locating dowels, then the mating part comes in from above piloted by the dowels to acceptable alignment. Secure the two halves with your bolted joint.

This approach produces very highly reliable seals at low piece price cost, but requires expensive tooling (optical recognition for o-rings etc),

IN theory, you could use temporary guide pins instead of permanent dowels, but I don't like that. The next guy who takes it apart will need to track down special alignment dowels and might not be able to re-align it.

 

[arkie6]

The hot oil smell is likely coming from the valve cover gasket leaking, which is a common BMW straight 6 turbo gas engine issue. It is very difficult to see the oil drip location at the back of the head unless you remove the engine cover and portions of the cowling, but you might be able to snake a borescope around there to get a look. It tends to accumulate and drip off the back lower corner onto or near the catalytic converter hanging off the turbo. Regarding oil, a motor oil containing Group V esters would generally tend to promote rubber gasket and seal swelling. An excellent option for this application is Mobil 1 ESP 0W-30 - I run it in my 2012 BMW X5 diesel with the M57 engine and my daughters 2017 X3 35i with the N55, both changed every 5k-6k miles. It is a "heavier" 30 weight at around 12 cST at 100C. You can search the forum for more detailed info on this oil.

 

[tired]

The hot oil smell is likely coming from the valve cover gasket leaking, which is a common BMW straight 6 turbo gas engine issue.

That's what I was thinking too. Leaks onto the exhaust and burns.

@BMWTurboDzl I wouldn't run any high mileage oils. I don't think they have any BMW approvals. I'd get the leak fixed, personally. Comes with the territory of owning a BMW, as I'm sure you already know.

 

[Prison_Mike]

That's what I was thinking too. Leaks onto the exhaust and burns.

@BMWTurboDzl I wouldn't run any high mileage oils. I don't think they have any BMW approvals. I'd get the leak fixed, personally. Comes with the territory of owning a BMW, as I'm sure you already know.

Yep. As the saying goes, if you can't afford a new BMW, you definitely can't afford a used one.

 

[RooflessVW]

One upon a time, Castrol Edge High Mileage 10W-40 was A3/B4 and is what I would recommend.

Not sure if that oil is still available.

Your valve cover gasket is leaking, though, and High Mileage oil or LM MoS won't fix it.

 

[BMWTurboDzl]

One upon a time, Castrol Edge High Mileage 10W-40 was A3/B4 and is what I would recommend.

Not sure if that oil is still available.

Your valve cover gasket is leaking, though, and High Mileage oil or LM MoS won't fix it.

It unlikely to be the VCG, I've looked multiple times, even the back side using a neighbors mirror on a stick. Besides I replaced it and the VC about 30k miles ago. I can't even smell it in the cabin which is what happens when the oil burns off the exhaust. No telltale puffs of smoke either. I'll look again and again and again of course.

We'll see as time goes on. I'd love to be able to drop the subframe and change out the oil pan gasket and turbo oil/coolant lines. Maybe even pull the bumper and replace the aux coolant and oil cooler. I have plenty of time these days.