Looks like 10w60 in an S50B30 is a bad idea..

[JJJames]

So I had the oil changed on my car recently and the shop recommended 10w60...i know I shouldn't have accepted but I was rushed and just wanted it dealt with..so I did.

Within a day after the change I started to notice the oil temp needle acting strangely...it would only get up to about 60-70 degrees C and then would sit there, even after an hour of highway driving. Occasionally it would jump up to 95C (normal) but usually would only last there for a minute or two. Car sounded fine, but clearly there was something wrong somewhere in the works.

Yesterday I had Mobil 1 0w40 put in...let literally all the 10w60 drain before install...and guess what..afterwards, the temp needle was totally fine, back to normal. Gradually rises to normal operating temp, and sits there like a rock with normal driving.

Take what you want from this account...I'm not a mechanic, and can't comment on how the mechanics of this might have worked...and I know that the logical construct "if x=a and a=b then x=b" is flawed, but facts are facts...and in this case, I was running 10w60 on Tuesday and the oil temp was way off/random, and then was running 0w40 on Wednesday and it was rock solid.

Cheers.

[444YYY]

I'm going to be brash here...
it's a co-incidence that you changed the oil and your temperature gauge problems disappeared......
Please report back in a months time, and let us know if it's fixed...
PS: Awesome dakar yellow M3 btw! My favourite colour!

[JJJames]

Sure, can do. You could be right...but its been driven over 1000kms since with no hint of the problem - and it disappeared immediately after the oil was changed..and started immediately after the 10w60 was put in initially..pretty weird coincidence..

[JCooper]

I can't see how oil viscosity would influence the temp needle swing so drastically in such a short period of time. I've been running 10w60 for the past 2 years and have never experienced any fluctuations like what you've described. If I had to guess id say you have an intermittent electrical problem, possibly with the temp sender/cluster or even in between.

http://imageshack.com/a/img539/2190/KHOVuU.jpg

[JJJames]

I can't see how oil viscosity would influence the temp needle swing so drastically in such a short period of time. I've been running 10w60 for the past 2 years and have never experienced any fluctuations like what you've described. If I had to guess id say you have an intermittent electrical problem, possibly with the temp sender/cluster or even in between.

How does the thermostat/sender work? Does oil flow through it at all?

Strange the problem only happened for the 3 weeks I had that oil in and stopped literally the first drive having changed it out...like someone threw a switch. I've driven the car about 50,000kms total and it only happened for the 1000 or so I had that oil in...pretty long odds.. But time will tell - if it happens again I will certainly update this post

[JCooper]

How does the thermostat/sender work? Does oil flow through it at all?

Strange the problem only happened for the 3 weeks I had that oil in and stopped literally the first drive having changed it out...like someone threw a switch. I've driven the car about 50,000kms total and it only happened for the 1000 or so I had that oil in...pretty long odds.. But time will tell - if it happens again I will certainly update this post

The thermostat in your oil loop works similar to the one in your coolant loop. It will stay shut while the oil is cold until it reaches a certain temperature. After the oil reaches that set temperature the wax in a small compartment within the thermostat melts from a solid to a liquid. The wax as a liquid displaces more area then as a solid so it ends up pushing a sealed rod/blocking plate outward allowing the oil to circulate through whatever channel was being blocked to the cooler. The oil sender on the otherhand is just another way of saying "oil temperature sensor" which basically is a resistor. A resistor whose resistance is influenced by the oil temperature, and no, oil does not flow through the sensor at all. Just around the probe itself. The sensor takes a reading of the oil temp and generates a resistance from it which in return propagates how much the needle should move. The lower the oil temperature reading is the higher the circuits resistance will be which means the needle will move less. The higher temperature leaves less resistance remaining within the circuit moving the temperature needle even further. For all of this too happen so quickly and drastically imo points to an electrical issue as I cant see oil fluctuation in temperature that quickly.

[kovrol]

I'm running the german type TWS 10W-60 for 5years now (4year in USA M3 S52 and 1,5year in Euro S50B32) without any issues...I usually change it in approx 6-7000kms, because in the S52 engine after 8000kms I had to add +1L to reach 10.000kms...strange but the TWS is fine for max 8000kms for me.

[JJJames]

The thermostat in your oil loop works similar to the one in your coolant loop. It will stay shut while the oil is cold until it reaches a certain temperature. After the oil reaches that set temperature the wax in a small compartment within the thermostat melts from a solid to a liquid. The wax as a liquid displaces more area then as a solid so it ends up pushing a sealed rod/blocking plate outward allowing the oil to circulate through whatever channel was being blocked to the cooler. The oil sender on the otherhand is just another way of saying "oil temperature sensor" which basically is a resistor. A resistor whose resistance is influenced by the oil temperature, and no, oil does not flow through the sensor at all. Just around the probe itself. The sensor takes a reading of the oil temp and generates a resistance from it which in return propagates how much the needle should move. The lower the oil temperature reading is the higher the circuits resistance will be which means the needle will move less. The higher temperature leaves less resistance remaining within the circuit moving the temperature needle even further. For all of this too happen so quickly and drastically imo points to an electrical issue as I cant see oil fluctuation in temperature that quickly.

Definitely agree the oil temp wasn't fluctuating that quickly - I wondered if the thicker oil might have had difficulty flowing or if there might have been pressure differences (spikes/low areas) which could disrupt flow around the sensor and change the reading quickly. Still no repeat of the problem..

[vanhack]

I think you just hit the nail on the head. 10w-50 is just too thick for the s50b3x, despite what dealers say, there was also an update to TIS for the correction. The best weight for high temp conditions and road driving is 5w-40. The 10w is good for the e46 s54 engine.

[444YYY]

Vanhack, can you send us the updated TIS you refer to above.
Thanks

[vanhack]

I have been looking for the snippet of the TIS on m3cutters.co.uk forum but cant find it anymore. I assure you that it is true that 5W 40 is the correct oil

[444YYY]

Please, I would love to see the TIS. I don't disagree with you, but want to see where they changed their mind from 10W60....

[vanhack]

I will post on the forum for someone to find the update.

[444YYY]

Thanks

[vanhack]

Just an update, the other forum folks cannot find the TIS update. They have an update, but it is from bmw us, so not relevant. It clearly states that pre 99 cars are to use bmw longline, which is 5W-40. https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0CD0QFjAE&url=https%3A%2F%2Fwww.bimmerfest.com%2Fforums%2Fat tachment.php%3Fattachmentid%3D226013%26d%3D1271202 627&ei=A06WVd2SL8qeNuCguvgH&usg=AFQjCNF-lW_yg69ZOb2VGsqUr9pe9TFUUw&bvm=bv.96952980,d.eXY

Hope you can see the link. But most s50b3x owners in UK are using 5w-40 now, due to vans noise and to save, bearings.

[MParallel]

Unless it's a 100% trackcar, the S50B3x still want 5w40.

The Vanos channels aren't designed for 10w60.

The best (ester based fully syth) oil is what you want. Like Fuchs Titan Pro S, Motul 300V.

Most I know, including a friend who is an engineer and myself, we all use Fuchs Titan and regard it as liquid gold for our S50B32's.

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Just an update, the other forum folks cannot find the TIS update. They have an update, but it is from bmw us, so not relevant. It clearly states that pre 99 cars are to use bmw longline, which is 5W-40. https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0CD0QFjAE&url=https%3A%2F%2Fwww.bimmerfest.com%2Fforums%2Fat tachment.php%3Fattachmentid%3D226013%26d%3D1271202 627&ei=A06WVd2SL8qeNuCguvgH&usg=AFQjCNF-lW_yg69ZOb2VGsqUr9pe9TFUUw&bvm=bv.96952980,d.eXY

Hope you can see the link. But most s50b3x owners in UK are using 5w-40 now, due to vans noise and to save, bearings.

This. The TIS was posted a few days ago on Cutters, but I also mentioned there it's a BMW NA TIS, so doesn't apply at all to EU E36 M3's.

[444YYY]

Agreed it is US specific, but a good read never the less!

It does not say that one cannot use 10W60 on a S50B30/2!

I was hoping it would make a proper recommendation for the S50B30, and say "do not use 10W60 in the S50B30" lol

Truth be told, BMW does not care about what oil they use in the S50B30 anymore, as these engine are out of warranty many years ago. For what's it's worth, the owners manual recommends 15W40 as the factory recommended oil!

[vanhack]

Yeah I have the manual too, but I am using 5w-40, mainly as my car is used once or twice a week. So need the flow of oil to be better on startup. And 10w-60 was never around during the production of the s50b3x motors

[MParallel]

15w40 might be for the B30?

All I know is the car loves the Fuchs 5w40 and so does the Vanos.

[vanhack]

Yes owners manual in the b30 is 15W-40.

[Jim E.]

Unless it's a 100% trackcar, the S50B3x still want 5w40.

The Vanos channels aren't designed for 10w60.

The best (ester based fully syth) oil is what you want. Like Fuchs Titan Pro S, Motul 300V.

Most I know, including a friend who is an engineer and myself, we all use Fuchs Titan and regard it as liquid gold for our S50B32's.

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This. The TIS was posted a few days ago on Cutters, but I also mentioned there it's a BMW NA TIS, so doesn't apply at all to EU E36 M3's.

FYI: The TIS is the same for US and EU. You just need to specify the right engine etc.... All the docs are on there.

And for everyone's reference, BMW recommended oils for the S14, S50 (30/32), S50US, S52, S70 etc... are all the same. I am excluding the S54, S62 (up to 3/2000) and S65, S85 which spec out the 10W60.

So much disinformation out there about oils it's utterly baffling. Even BMW's latest specs are contradictory.

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15w40 might be for the B30?

All I know is the car loves the Fuchs 5w40 and so does the Vanos.

There is no specific single viscosity recommended for the B30. Back in the day before BMW started to use their Longlife specs, you needed to be more diligent and keep your eye on viscosity grades which is why they gave you a chart in the manual. When longlife specs took over, BMW tested these oils to ensure their recommendation could be used worldwide at any time of the year regardless of ambient temps.

Your 5W40 is a very good oil for the B32 as a street car. But it can also be used in the B30 etc....

[444YYY]

I am using Mobil 1 0W40 for my B30. I am in South Africa, and I feel 0W is overkill for our climate (because we do not get ambient temperatures below 0 deg C), I have chosen the Mobil 1 0W40, due to its quality! Its Porsches Recomended oil!

Just sharing what I have chosen.

And my B30 did have TWS 10W60 from 120 to 170 k km, over a period of 6 years, when it was serviced by the dealer....
So it has seen this oil for 50 000km! The engine was still a sliver colour (and not the golden honey colour) when the top cover was opened at 172 k!

[MParallel]

Not sure why an oil would be good, whatever it is, when Porsche recommands it. You even put an exclamation point at the end.

Totally different engines.

[444YYY]

Quality. My opinion though...

[foler]

last use in my car is castrol edge tws professional fst. this is only oil which wont change color after 6000 miles. fantastic oil.

http://i.ebayimg.com/images/i/151233476278-0-1/s-l1000.jpg

also read this
TWS Motorsport & EDGE Pro TWS are Different! - Blackstone Report
http://www.m3post.com/forums/showthread.php?t=926080