Open discussion-Conventional oil in our engines

[Gray_Panther]

With many of us reaching 6-digit mileages or past the 50k mark, we are beginning to see more threads about oil leaking from the gaskets.

I remember watching a Youtube video where a mechanic used conventional oil every while to keep the gaskets lubricated. He explained that full synthetic oil that we use in our engines slowly dry out the rubber gaskets which causes cracks and breakdown of the material which is why we experience oil leaks between the 80-120k mile range.

My question is thus:
Is it ok to use conventional oil with our N51/52/54/55 engines?
And if so, which kind?

[MZWIE]

I have only used synthetic from day one. No oil leaks at all. 150k miles.

[c1pher]

I am not sure what the answer will be but I owned a Jeep with high miles and thought going to full synthetic would help the motor but I started getting leaks all over and found out that going from dino oil to synthetic after so many miles is not a good thing.

I think most engines now have such tight tolerances, using potentially thicker traditional oil might be detrimental to newer motors. I'm not an enginologist though.

[The Wind Breezes]

Try using Google and making up your own mind on the issue...in short, no. Your mechanic is misinformed since synthetic won't cause gaskets to leak any more than regular oil. But, you can use basically whatever oil you want, even something like olive oil wouldn't grenade your motor if you changed it often. Regular oil is fine, and cheaper. But, why drive an overpriced car with an overcomplicated engine and try to save a few pennies when you have to pay it all back by changing the oil more frequently?

[ianc]

I too have heard anecdotal evidence of older engines suddenly leaking when given synthetic oil late in life, but never that dino oil will 'lubricate' gaskets and seals.

Our engines, particularly turbo engines, are designed to run hotter than older engines for reasons of thermal efficiency, and consequently need the additional protection that synthetics can provide. It would indeed be a false economy to run conventional oil in them whatever the reason.

And e34m5; 150k and not even an OFHG leak? I'm highly, highly skeptical...

ianc

[Dackelone]

Originally Posted by Gray_Panther

My question is thus:
Is it ok to use conventional oil with our N51/52/54/55 engines?

No. The reason of course is because BMW says to only use a synthetic oil - so one should use a synthetic. Always use an oil that meets BMW's oil rating requirements - listed in your owners manual.


Perhaps the reason why some see oil leaks from gaskets and such is from the seals just getting old and hard. This is to be expected over time. Just as it is expected to be replacing old hardened coolant hoses and rotted vacuum lines.

[NVHoo]

Originally Posted by ianc

I too have heard anecdotal evidence of older engines suddenly leaking when given synthetic oil late in life, but never that dino oil will 'lubricate' gaskets and seals.

Our engines, particularly turbo engines, are designed to run hotter than older engines for reasons of thermal efficiency, and consequently need the additional protection that synthetics can provide. It would indeed be a false economy to run conventional oil in them whatever the reason.

And e34m5; 150k and not even an OFHG leak? I'm highly, highly skeptical...

ianc

There were a lot of anecdotal stories decades ago about folks who always used single viscosity oil in their engines developing leaks and engine failures when they switched to higher detergent/additive multi-viscosity oil late in the life of the car. The answer was that the better oil cleaned the internals better, including washing away grime/sludge that had built up for years. The removal of the junk opened small holes that the junk had naturally clogged through seepage, and/or opened up gaps in bearings etc.

The OPs mechanic is just wrong. IMO, using anything other than BMW spec synthetic oil at 10K change intervals is asking for trouble.

[Gray_Panther]

Guys, I'd like you to reread my original post. I only said I came across a Youtube video where that idea stemmed from.

My father and I are our own mechanics and I have always used full synthetic oil on my cars.

I was just thinking of a way to prevent the leaks from happening. The gasket repair is easy to perform since we just did it on our X3.

[JimD]

I kind of doubt that conventional oil, with frequent oil changes, would cause damage to our engines. But I am not going to try it. I use synthetic oil in my Suzuki even though conventional is OK with that manufacturer. It just doesn't seem like something to try and save money on. I also don't think there are any advantages of conventional oil.

My son like Rotella, however, especially after a rebuild. But he isn't into BMWs.

[6MT_Addict]

Originally Posted by JimD

I kind of doubt that conventional oil, with frequent oil changes, would cause damage to our engines. But I am not going to try it. I use synthetic oil in my Suzuki even though conventional is OK with that manufacturer. It just doesn't seem like something to try and save money on. I also don't think there are any advantages of conventional oil.

My son like Rotella, however, especially after a rebuild. But he isn't into BMWs.

Maybe on an NA engine, but I wouldn't use conventional on an N54/55. The turbos get extremely hot and if the conventional oil is either too thick or does not have a high enough temp rating those turbos could be starved pretty easily. I'm no expert, just a thought.

[Southjersey128]

Originally Posted by e34m5

I have only used synthetic from day one. No oil leaks at all. 150k miles.

This is amazing. I wonder if being in a warmer climate (I see you're from GA) helps keep the gaskets from drying out. I've had to do the oil filter stand and valve cover gasket at 76k miles. All BMW's at my shop start leaking about the same time, 7-8 years no matter the mileage.

[desertman123]

Originally Posted by Southjersey128

This is amazing. I wonder if being in a warmer climate (I see you're from GA) helps keep the gaskets from drying out. I've had to do the oil filter stand and valve cover gasket at 76k miles. All BMW's at my shop start leaking about the same time, 7-8 years no matter the mileage.

Florida here, 100% anecdotal but both my and my neighbours N52 developed valve cover leaks. I had 2008 w 80k, no idea what he had but it was a pre lci 328i.

Also the conventional oil statement is about as absurd as the 87octane threads.

Like Jim said, I'm sure frequent (5k MAX) conventional changes wouldn't actually hurt anything, but I'd always have it in the back of my mind. One could argue this engine was built around synthetic, so bearings and complex things like VANOS might suffer

[Mr Rooty Von Tooty]

Synthetic oil are recommended for turbo engines due to not breaking down under the stress of high heat. You'll notice the temperature gauge monitors oil temperature and not water. Also it flow faster under cold temperatures.

However, there are dino oils that perform almost as well as synthetics. In any non-turbo engine a dino oil will be OK. If it's an oil burner, I'd use drain oil guys are dropping off at Auto Zone.

[MightyMouseTech]

Originally Posted by Gray_Panther

I remember watching a Youtube video where a mechanic used conventional oil every while to keep the gaskets lubricated. He explained that full synthetic oil that we use in our engines slowly dry out the rubber gaskets which causes cracks and breakdown of the material which is why we experience oil leaks between the 80-120k mile range.

That is an old wives tale.

I have always used full synthetics in all my cars, and I usually drive them till the 300k mark. I have never had an oil leak, ever. But I do not follow the recommended interval, every 6000 km for me.

[iminhell1]

http://www.speedtalk.com/forum/viewt...hp?f=1&t=31363


I didn't read through it all but it looks appealing ...

[KNS]

Originally Posted by e34m5

I have only used synthetic from day one. No oil leaks at all. 150k miles.

I've had my E46 since new - 208,000 miles on it now and synthetic from day one. Rotella T6 for the last 100,000 miles (or more).

I've only had one leak and that was the oil filter housing gasket. I replaced the valve cover gasket at 60,000 miles (just because), it wasn't leaking and was actually still soft and pliable. The replacement is still dry. The oil pan has had some "wetness" but still hasn't been leaving drips in the under tray. Overall the engine is pretty darn dry.

I attribute the condition of my engine and lack of leaks more to the way I drive and treat my car than the oil I use. I avoid any prolonged idling, it's one of the worst things you can do to your engine.

You might be okay with conventional oil in a NA engine but if you're running turbos use a synthetic.

[mackeroni]

Originally Posted by Gray_Panther

I remember watching a Youtube video where a mechanic used conventional oil every while to keep the gaskets lubricated. He explained that full synthetic oil that we use in our engines slowly dry out the rubber gaskets which causes cracks and breakdown of the material which is why we experience oil leaks between the 80-120k mile range.

Myth

[ejm3]

Originally Posted by Dackelone

Perhaps the reason why some see oil leaks from gaskets and such is from the seals just getting old and hard. This is to be expected over time. Just as it is expected to be replacing old hardened coolant hoses and rotted vacuum lines.

I would love to believe this is the case but my oil filter housing gaskets started leaking at 4 years and 42k miles.

Of course about 2 months after the warranty expired....

[jaye944]

Originally Posted by Dackelone

No. The reason of course is because BMW says to only use a synthetic oil - so one should use a synthetic. Always use an oil that meets BMW's oil rating requirements - listed in your owners manual.


Perhaps the reason why some see oil leaks from gaskets and such is from the seals just getting old and hard. This is to be expected over time. Just as it is expected to be replacing old hardened coolant hoses and rotted vacuum lines.

^^^^^^^^^^^^^^

[Dackelone]

Originally Posted by ejm3

I would love to believe this is the case but my oil filter housing gaskets started leaking at 4 years and 42k miles.

Of course about 2 months after the warranty expired....

The oil filter housing gaskets do go bad. But a lot of times its from techs over tightening the oil filter cap/cover. Most people go all "gorilla" on it. There is only three bolts holding that housing to the head. So its easy to "move" the flange when over tightening it.

[Matticus91]

Didn't get to read all the replies so apologies if this was already mentioned - I am pretty sure the majority of our seals/gaskets are not even rubber, they are silicone, so using "dino" oil to lube them wouldn't make any difference anyway.