Unusual oil temperatures and oil behavior - 08 S65 142K miles / VAC / CSF Rad

[jeremyuhh]

SOLVED: page 5, post #103: https://www.m3post.com/forums/showth...1808462&page=5

Complete walk through with part numbers on what i did and how i did it: https://www.m3post.com/forums/showth...2#post27658872

________________________________________________

Hello everyone, I don't post much unless I'm truly stumped.

This is my 2nd E90 M3, so I have something to compare it to - same year, same trans, same set up, and similar mileage (kind of). I always give about 2-3 min for the car to warm up and do not rev passed 3k until oil temps near 210 and rev limiter is completely down.

Previous E90 M3:
2008, 6spd, 3 owners, OEM WPC bearings at 36k miles, stock cooling, 2 auto-x, 2 track days, purchased with 75k miles sold at 112k miles.

Temps were pretty "normal/average" except for the summer of 2018, looking back, this seems pretty normal and acceptable to me now: https://www.m3post.com/forums/showthread.php?t=1513213

Current E90 M3:
2008, 6spd, 4 owners?, VAC bearings at 85k @ MRF, CSF radiator, new water pump w/ metal impeller, PO had it for 5 years as DD, purchased at 143k miles, currently at 144K miles. Engine does not make funny sounds, no knocking or unusually loud ticking or clanking or anything. Engine has Alpine stage 1 tune. Everything else is stock.

During my test drive, temps were fine. Drive home - 60ish highway miles, temps were fine. In a few days, oil temps started to catch my eye because it would start to pass 210F with normal street driving.

1st incident - 02/18:
Street driving around town
not going passed 4k rpm
normal driving, not pushing or driving "hard"
day, 68F outside temp
A/C off
oil from Nov. 2019, estimated 138k miles


2nd incident - 02/19:
Highway, cruising under 70 mph
trying to keep it at or under 3k rpm
normal driving, not pushing or driving "hard"
uphill
night, 57F outside temp
A/C off
oil from Nov. 2019, estimated 138k miles


3rd incident - 02/22:
highway drive to work and back 40 mile round trip, idling in garage before shut off
normal driving, not pushing or driving "hard"
morning, 68F outside temp
A/C off
liquimoly 10W-60 oil change


4th incident - 03/02:
highway driving
normal driving, not pushing or driving "hard"
tried to stay above 3k to keep air flowing after reading a member say the S65 needs to have air flowing, not under 3k with load.
afternoon, 74F outside temp
A/C off
lqiuimoly 10W-60


5th incident - 03/06:
highway driving
normal driving, tried to keep above 3k again
morning, 53F outside temp
liqiuimoly 10W-60


6th incident - 03/13:
idle, after filling up gas tank
night, 52F outside temp
city driving, tame not pushing
liqiuimoly 10W-60


7th incident - 3/16:
Documented this from start up to shut down.
Oil gets to operating temp in about 5-8 min, is this normal ? Given the outside temperature was 39F
the freeway entrance is less than a mile from my house, this is after a mile or two on the highway:


still on freeway:


just exited (youd think it would cool down):


drove about a mile, idle, waiting to turn left, temps still rising:


got to work, temps when down as soon as I came to a stop and idled, then parked:


left work and drove about 1/4 mile, no A/C, no high revving, pulled off into some parking lot:


creeping out of the parking lot, temps dropped (i dont get it):

[B]
A little hard to see but temps stayed this way for the whole 22 mile highway drive home, normal 6th gear cruising, no high revs or abrupt acceleration (i felt if it was hotter outside the temps would have reached the same as incident 4):


pulled in to my garage and idled, bimmerlink shows temps at 225F at 38F outside temp:


Later in the same day, had to run errands a bit after i got home. Car sat for about 5 hours, here is a cold start at 12:59 PM:


At 1:09 PM oil temps were covering the "2" in 210, is that considered operating temp? At 1:15 it was here:
[/url]

Stopped and idled at Whole Foods waiting for my groceries and temps climbed a bit while sitting:


Drove about 1.5 miles to Chic Fil A, stopped and idled, waiting for our food and temps climbed again while idling:


The whole drive home, i probably hit 2 red lights, temps stayed here:


Pulled into my garage, idled and temps went up again:


From what I've gathered, it does not matter if i street or highway drive, my temps will go higher than usual. More so when i am at a stop or idling, it seems. I do not drive the car "hard" while I'm trying to figure this out and i always warm it up and drive under 3k after a cold start till the engine is warm. Engine seems/sounds healthy, feels as good as my old one. Except in this weather, my old one never did this. I've also asked friends who have the same car and they comment on how strange and high my temps are.

Also puzzling when I'm just highway cruising, no A/C, with relatively low outside temps, that the car oil will still rise. And continue to rise or fluctuate, even when exiting the freeway or from light to light. 240F is the highest ive seen it, from normal driving during a 75F degree day.

I understand at a stop/idle there is no airflow, but i don't understand why its rising so high. Engine has zero load so i imagine temps would go down to "normal" each time. It drops sometimes when the fan is blowing on its highest setting. Most times I park the car in my garage, the fan is still blowing for a few min after i shut the car off.

VAC bearings have 59k miles on them (done at 85k and i am currently at 144k), I'm going to replace them soon. Oil cooler has some dented fins, going to try to straight out and clean them and after reading enough threads on aftermarket oil coolers, i don't think that will help me? any thoughts? Contemplated the oil diverter valve but most say its not good for a street car as oil temps will take too long to rise, esp. in winter. I've read in other threads this could be main bearing wear? I really hope that is not the case. Sorry for the essay of a post. Any insight will be appreciated.

[NeverL8]

I don’t think it’s bearing related....could be your thermostat and/or coolant temperature sensor?

Any codes?

[DRLane]

Most of those seem very reasonable temps. Have an OBD tool to read actual disparate coolant and oil temps?

[irokwrx]

Have you ever changed your thermostat? I was running a lil hot last summer when I was running Liquid Molly. I replaced my thermostat and started running Castrol 10-60 and it never ran hot again, not saying it was the oil but it never ran that hot again. I am also SC and I have an intercooler blocking the oil cooler. Try changing your thermostat and see if that helps. I don't think a few bent fins are a big issue.

[roastbeef]

how is your front felt undertray?

[Davisca455]

Originally Posted by roastbeef

how is your front felt undertray?

Great question.

The first thing I noticed after I replaced my broken ass under tray, was how much longer my oil temp gauge stayed under 210 than it had before.
Even though the temp indicator on the tach would read at full ready, the oil temp gauge was way under 210 and it seemed like it took 20 miles at freeway speeds for the oil temp to normalize at around 210 if it was cooler outside.
That was never the situation before the new felt tray.
Overall, I think the new felt tray was a 2 needle widths improvement for my oil temp.

However, your gauge looks like mine when I'm doing 80-90 in the mountains on a 100f day.

[Ajolives]

Looks like all the culprits have been covered and can easily be any of the suggestions...although I did my thermostat not too long ago and my oil temps are much more stable now. I had kind of the opposite problem - my temps would never go above 210 unless I was really giving the car hell, even in FL summers. It would maybe reach 190 in cooler weather. That all changed after the thermostat, I'm right at 200 every time regardless of temps outside now.

[jeremyuhh]

Originally Posted by TheRussski

I don’t think it’s bearing related....could be your thermostat and/or coolant temperature sensor?

Any codes?

Originally Posted by Ajolives

Looks like all the culprits have been covered and can easily be any of the suggestions...although I did my thermostat not too long ago and my oil temps are much more stable now. I had kind of the opposite problem - my temps would never go above 210 unless I was really giving the car hell, even in FL summers. It would maybe reach 190 in cooler weather. That all changed after the thermostat, I'm right at 200 every time regardless of temps outside now.

Originally Posted by irokwrx

Have you ever changed your thermostat? I was running a lil hot last summer when I was running Liquid Molly. I replaced my thermostat and started running Castrol 10-60 and it never ran hot again, not saying it was the oil but it never ran that hot again. I am also SC and I have an intercooler blocking the oil cooler. Try changing your thermostat and see if that helps. I don't think a few bent fins are a big issue.

No codes. Thermostat was replaced when the whole cooling system was refreshed.

Looking at the invoice: 4 O rings, water hose, water pump with metal impeller, thermostat, bmw blue antifreeze, ac belt, drive belt, brake fluid with SRF... back in April of 2018 at Trinity Autosport....3 years ago.

Could a thermostat go bad that quickly ?

Going to switch back to BMW's 10W-60 for the next oil change.

[jeremyuhh]

Originally Posted by DRLane

Most of those seem very reasonable temps. Have an OBD tool to read actual disparate coolant and oil temps?

Yes, i kept track of it today with bimmerlink.

They don't seem reasonable for regular tame street driving. Im talking normal acceleration, not shifting passed 4k, not gunning it or sudden stabs at the throttle.

[jeremyuhh]

Originally Posted by roastbeef

how is your front felt undertray?

Originally Posted by Davisca455

Great question.

The first thing I noticed after I replaced my broken ass under tray, was how much longer my oil temp gauge stayed under 210 than it had before.
Even though the temp indicator on the tach would read at full ready, the oil temp gauge was way under 210 and it seemed like it took 20 miles at freeway speeds for the oil temp to normalize at around 210 if it was cooler outside.
That was never the situation before the new felt tray.
Overall, I think the new felt tray was a 2 needle widths improvement for my oil temp.

However, your gauge looks like mine when I'm doing 80-90 in the mountains on a 100f day.

This. Someone mentioned that in my post about temps with my old car. In my previous m3, the tray was jacked up, but only got high temps in the summer.

My current M3 has a deansbimmer undertray that is unscathed.

And exactly, im not even pushing the car or driving it like it should be driven and my temps are on the high side. Its driving me nuts.

[roastbeef]

oil and water temps are going to be somewhat sympathetic of each other, but there is still going to be a delta.
your car has high mileage, and if your undertray is intact, consider taking off the bumper and really taking a look at the cooling fins on the heat exchanger and a/c condenser. bent fins and embedded bugs will impact cooling. if the condenser is in really bad shape, it literally blocks air from reaching the main heat exchanger.
i clean my dct cooler from time to time when i have the bumper off, but i haven't needed to clean the main radiator. there is usually a little piece of rubber, a couple bees, a moth, and some straw wedged in the fins. i'll also straighten out a few areas of the fins if they are bent up enough. there is enough of a mess to have to sweep it up after i move the car and it all adds up to poor efficiency in cooling.

[jeremyuhh]

Originally Posted by roastbeef

oil and water temps are going to be somewhat sympathetic of each other, but there are still going to be a delta.
your car has high mileage, and if your undertray is intact, consider taking off the bumper and really taking a look at the cooling fins on the heat exchanger and a/c condenser. bent fins and embedded bugs will impact cooling. if the condenser is in really bad shape, it literally blocks air from reaching the main heat exchanger.
i clean my dct cooler from time to time when i have the bumper off, but i haven't needed to clean the main radiator. there is usually a little piece of rubber, a couple bees, a moth, and some straw wedged in the fins. i'll also straighten out a few areas of the fins if they are bent up enough. there is enough of a mess to have to sweep it up after i move the car and it all adds up to poor efficiency in cooling.

That makes plenty of sense and will definitely give that a try, thanks. Is that what is directly behind the grills and in front of the radiator, the a/c condenser?

[Scrippy]

I don't want to come off pessimistic but these temps don't strike me as odd. Given your mileage have you ever done the thermostat? I haven't used my undertray in over 3 years and it does not contribute to random temps at all if we can call these random. I live in Cali so heat would get me in traffic. Yes I read the thorough posts with each pic. I'm curious why this is even a RB thought? I have 225,000 and I saw this before my thermostat change and it went away when I replaced it. Maybe I'm missing something but your variance is less than 8-10 degrees, so why panic? Change your thermostat, fluids and maybe hoses but relax ultimately. My gosh the panic in here is ridiculous.

[roastbeef]

Originally Posted by jeremyuhh

That makes plenty of sense and will definitely give that a try, thanks. Is that what is directly behind the grills and in front of the radiator, the a/c condenser?

yes. you can probably take a look without the hassle of removing the bumper.

[roastbeef]

Originally Posted by jeremyuhh

Most times I park the car in my garage, the fan is still blowing for a few min after i shut the car off.

i think this could be a clue. i have never had this happen with spirited driving or after a cool down lap at the track when the car was still pretty hot. there is probably something screwed up with the efan or the management system.

i also run liqui moly 10/60. i do think LM has a reputation for running slightly warmer, but given your circumstances, i don't think that is your issue. my car runs on the cool side, and i really have to try to get the needle to go above the 1/2 way mark.

[atopa2002]

Your temp is not out of the norm to me but to put your mind at rest you can install the Epic oil diverter valve

[NeverL8]

Originally Posted by jeremyuhh

No codes. Thermostat was replaced when the whole cooling system was refreshed.

Looking at the invoice: 4 O rings, water hose, water pump with metal impeller, thermostat, bmw blue antifreeze, ac belt, drive belt, brake fluid with SRF... back in April of 2018 at Trinity Autosport....3 years ago.

Could a thermostat go bad that quickly ?

Going to switch back to BMW's 10W-60 for the next oil change.

So they didn’t replace temp sensor? It’s not part of thermostat itself, it goes into the side of thermostat housing. That part gets gunky over time and only costs like $45

[jeremyuhh]

Originally Posted by Scrippy

I don't want to come off pessimistic but these temps don't strike me as odd. Given your mileage have you ever done the thermostat? I haven't used my undertray in over 3 years and it does not contribute to random temps at all if we can call these random. I live in Cali so heat would get me in traffic. Yes I read the thorough posts with each pic. I'm curious why this is even a RB thought? I have 225,000 and I saw this before my thermostat change and it went away when I replaced it. Maybe I'm missing something but your variance is less than 8-10 degrees, so why panic? Change your thermostat, fluids and maybe hoses but relax ultimately. My gosh the panic in here is ridiculous.

im not panicking. im just wondering why my temps are higher than normal. higher than my old car and higher than everyone else ive spoken to. I just dont understand and would like to fix it before it becomes a problem.

If you read my responses, the thermostat was changed in 2018 when the whole cooling system was refreshed, along with hoses and fluids. Ill try changing my thermostat anyway.

i was not sitting in any CA traffic when i took photos of these temps. this was mostly highway cruising, no traffic, at 75-80mph. and regular street driving.

I never thought it was an RB issue until i read other posts about oil temps being high: https://www.m3post.com/forums/showth...1399371&page=3

You even said yourself:

Originally Posted by Scrippy

Describe what's going on here or this post is useless. For the ambient temp of 70's that is a high temp motor temp. I see my M in this temp range when it is hot out and I'm NOT MOVING IN TRAFFIC. Lack of airflow on a hot day will produce this temp reading.

how is this any different from this, moving in no traffic on the freeway.


or this, after driving in no traffic and sitting in my garage in 38F degree weather? I dont think the engine should reach those temps in traffic-less street driving.


I still dont think it is, but im probably going to change them out just for good measure.

[jeremyuhh]

Originally Posted by TheRussski

So they didn’t replace temp sensor? It’s not part of thermostat itself, it goes into the side of thermostat housing. That part gets gunky over time and only costs like $45

According to the invoice no. I'll look into that, thank you.

[amrazM]

check coolant temps, if coolant is going above 192* during normal operation something is wrong.

[fsmtnbiker]

Replace the coolant temp sensor and the pigtail to it, that likely will resolve this. That gauge is a blend of coolant and oil temps, so any erroneous reading will have an effect. The pigtail to the coolant temp sensor is a known issue and causes all kinds of weirdness in this gauge reading.

I had similar symptoms and eventually starting occasionally getting a CEL for the coolant temp sensor. Didn't resolve it until I replaced the wiring pigtail as well.

PN 12517847971 for harness, 13621433076 for sensor

[jeremyuhh]

Originally Posted by amrazM

check coolant temps, if coolant is going above 192* during normal operation something is wrong.

I'm monitoring via BimmerLink app but don't see a parameter for coolant temp? Is it called something else, do you know ?

I can also try to find my Carly and try with that.