Help needed. 650i High and fluctuating oil temp

[b1scu17]

Hey everyone

So end of Jan 2018 I took my 2007 E63 650i for a service. Told them I'm having a overheating issue. The mechanic literally just shrugged his shoulders and said he can't find anything wrong and did a coolant pressure test and saw no leaks.
Two days later I investigated it and saw the lower hose o-ring leaking?!
Took it back and leak was sorted but still coolant temp was reaching 120C.
So last week being 7 weeks later and after lots of back and forth, finally the fan was found to be faulty and coolant temp now stays at a good 98-102 C.
They did also say they replaced some oil related sensor costing R6300?!
Still don't understand that... Gonna try to find out today what exactly they replaced.

So my issue is the oil temp. I have a 2007 650i and my mother happens to have a 2009 650i. Same N62 engines. Her 650i is behaving how mine used to. Oil temp hovers quite stably at 98-102C. Mine is very erratic, jumping around alot as in the attached video.
Yesterday after fetching the car from the mechanics, driving very calmly never going over about 3800rpm in about 28.5C ambient temp in PTA, the car's oil temp would hover around 108-110C while the 2009 650i driving the same route right in front of me would be hovering at a stable 98-102C while driving a bit harder here and there and slowing down so I could catch up, never going over about 102C.
I drove a bit harder when getting closer to home and my 2007 650's oil temp would reach about 115C and the 2009 650 would stay at 102-105 MAX.
That's exactly how mine used to be.

The garage owner and mechanics keep telling me anything under 120C is ok, but
1) the car NEVER behaved like this before
2) Here is an identical 650i we bought from them as well that's running 98-102C stably?!
3) With two of the same 650i, how does mine seem normal to them?

Here's a video of someone's else BMW doing EXACTLY what mine is doing
BMW oil temp fluctuating video

This guy in the video replaced the DME and it was sorted. They're thinking with the DME controlled tstat and the DME not reading temp sensor's info correctly, the DME didn't let the thermostat open enough to allow for sufficient water circulation through the engine and it causes the oil temp to increase and then fluctuate like this.

Anyone else experience this before?

 

[SubLoaded]

Same oil viscosity in both cars?

Engine temps seem fine to me.

 

[b1scu17]

Same oil viscosity in both cars?

Engine temps seem fine to me.

Haven't been able to find out from them exactly what oil is in both cars, which kinda does worry me...
I don't trust that mechanic one bit... I mean, his pressure test showed him nothing, yet I was able to SEE the coolant leak 2 days later. Asked him to flush the coolant when servicing the car and put in antifreeze again, and they didn't touch the coolant. Still had normal tap water I put in the car when stopping at a garage after a warning light came on the day before just to get home 4 kms away.
Took it back and asked him again to put in antifreeze and distilled water according to BMW's specifications and he then put in STILL water... :dunnoanymore:
I cannot trust that he even put in the correct oil... Been battling to find out...

What would the recommended oil be for our climate? 5W30 or 5W40?
And how would each one affect the oil temp? Especially in a way like in the linked video? Car never used to get even remotely close to these kinds of temps but now it gets up to 110C at idle and just revving the car

 

[SubLoaded]

Not entirely sure hey. I've heard that both 5W30 and 5W40 can be used.

Personally, I use 5W30 but I have the N52 motor. Not sure how/if yours would differ.

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Fresh oil can never harm an engine and oil is cheaper than an engine. Don't let a bill make you stick with a mech if you don't trust him. I mean, you don't want extensive damage to your car.

If it was me then I'd do an oil change just to be safe and maybe do a coolant flush while you're at it. It'll be an inconvenient but inexpensive Savior to your vehicle if you're having doubts.

 

[Kish2604]

what sort of mileage does your car have? if its over the 150k kms mark i would ask when last has the motor been really properly flushed? i would think that the long bmw service intervals has started to gum up oil channels, coolers if there are any and oil filter housing.

open your oil cap and inspect for a gooey paste in the lip of the cap or inside the valve cover.

 

[b1scu17]

Not entirely sure hey. I've heard that both 5W30 and 5W40 can be used.

Personally, I use 5W30 but I have the N52 motor. Not sure how/if yours would differ.

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Fresh oil can never harm an engine and oil is cheaper than an engine. Don't let a bill make you stick with a mech if you don't trust him. I mean, you don't want extensive damage to your car.

If it was me then I'd do an oil change just to be safe and maybe do a coolant flush while you're at it. It'll be an inconvenient but inexpensive Savior to your vehicle if you're having doubts.

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Cool thanks, I'm going there on Monday again cause tomorrow is a holiday then I'll again try to find out what oil they used exactly.
I've been planning to flush the coolant and thinking now about maybe doing the oil as well as soon as I actually get my car back. 8 weeks now that I've been without my car
They said they picked up an issue with my starter motor, replaced it, went to pick up my car and it wouldn't start. Left it there, they replaced the IVM, drove it back yesterday, got home, turned off the car and 5 minutes later I couldn't start the car again.
They're just throwing new parts at it haha

They replaced my battery last year and never registered it. Then had a ton of faults pop up at random times. Transmission fault, power steering fault, DSC fault, etc. Took it back, they replaced the battery again, then made sure to register the battery and no faults ever again.
They serviced the other 2009 650 before it was bought and didn't put in the air filter... They seem clueless and extremely negligent

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what sort of mileage does your car have? if its over the 150k kms mark i would ask when last has the motor been really properly flushed? i would think that the long bmw service intervals has started to gum up oil channels, coolers if there are any and oil filter housing.

open your oil cap and inspect for a gooey paste in the lip of the cap or inside the valve cover.

My 2007 650 has 92586kms
It's been running beautifully otherwise... It was just the fan issue that had them chasing their tales for 7 weeks mgwaiting:

Opened the oil cap yesterday and check the oil level at the dipstick cause I thought maybe it didn't have oil. The oil looked very good. Not dark when dripping it on a paper towel, no gooeyness in the lip of the cap, no residue, no odd discoloration, no odd smells. Couldn't inspect the valve cover though. Didn't have the car long enough yesterday

 

[Nikhil]

sorry for your troubles bud, which mechanic / dealership is this so we know where to stay clear

 

[SubLoaded]

Where are you based? If you're in Durban then I can recommend someone that can sort you out once and for all :thumbs:

 

[shark111]

I'm not sure what's the problem with the car, but if my mechanic made that many messups, I would definitely not have gone back as many times as you

 

[b1scu17]

sorry for your troubles bud, which mechanic / dealership is this so we know where to stay clear

I bought the car from is Mit Mak Motors. ABSOLUTELY AMAZING used car dealership to be honest. The quality of their cars are truly amazing (got two 650s from them) and I can't even begin to say how well they've treated me after the sale but it's just the mechanics department there that simply doesn't seem to really know what they're doing...

Their sales team and manager at MMM are just the best! 11 of of 10 rating!
The manager's help and support throughout all this has been out of this world! Personally coming to help me when my car gave problems at 8pm in the evening, giving me a courtesy car, paying for a flatbed to tow or transport my car, etc. The list just goes on!
I wouldn't buy a car from anyone else but I would just have someone else service and fix the car

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Where are you based? If you're in Durban then I can recommend someone that can sort you out once and for all :thumbs:

I'm from Pretoria... I'm looking around for someone that really know BMWs here. After I complained to the manager about his service department he sent the car to someone else who was able to get things fixed. But this oil temp thing is not popping up any fault codes and they just say my temps are normal but why are two 650's oil temps behaving so differently

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I'm not sure what's the problem with the car, but if my mechanic made that many messups, I would definitely not have gone back as many times as you

My extended warranty is with them, but after complaining to the manager he's been sending my car to someone else. Don't want that service department touching my car again. I've gotten a bunch stuff replaced for free luckily They sent the car to the BMW dealership today

 

[Maverick550]

I suspect that you while the correct oil spec is important, I don’t believe its affecting your oil temperature.
I agree that your car seems to be running hotter than what I would consider normal and you definitely need a synthetic oil for those kind of temperatures.

I suspect that within the cooling system you are losing pressure and that the car is in fact running hotter than normal. You are not finding it at the likely culprits because its probably some plastic piece under the engine cover, which is drippling onto a hot engine, hence not visible.
Further, at the car warms up, that component expands and leaks pressure from the system, which may explain the variable readings.
You would have to do a fair bit of driving and monitor to coolant level to know for sure.
The part in question may well seal when cold but leaks off pressure when hot, which is why the pressure test passed.

I has something similar on a car and only found the leak when the gearbox was removed from the car.
Some moulded plastic component has a hairline crack in it and as it was situated hidden from sight, it was only discovered when doing a repair to the flex plate.
There are obviously other things like the car running to lean, which would increase engine temperature but that you would see on the exhaust as an orange brown colour.
I’m not a mechanic and don’t work on my cars.. but the point I am attempting to make is that an oil change is not going to bring down the operating temperature.

You need to look at the cooling system, faulty thermostat etc.
I doubt you will have sludge in your motor with modern oils.

 

[De@nO]

Check for oil leaks, specifically the altenator bracket / oil cooler lines that feed in out and out the block. A significant leak will lead to lower oil pressure and higher oil tempretures.

I had something similar on my 650i. Replaced the seal as a DIY (Pain in the a$$ job and need to lift / support the motor) No more leaks, better oil pressure and lower temps, did an oil change and threw in some Liqui Moly Ceratec and Oil / Seal conditioner. She doesn't move past 105 max oil temp now, even when pushed hard! A ton of work but well worth it.

I will also be investigating how to lower the engine temps overall as these motors do run hot. Looking into lower temp thermostats and / or program the DME to open the thermo earlier, at a lower temp. IMO the reason for a lot of seals and rubbers going bad on the N62B48