[Tony_s]

Hello All,
So i am here today asking for your help with my cars problem. it began to over heat about a month ago and it only happen when the a/c was on. i normally just drive the car to school, work and then back home, so the car only runs for about a 25 min(+-15 miles) on its longest trip. i have been driving the car daily and no issues arise. it has only overheated twice on me and when that happen i immediately pulled over and let the vehicle sit for a while. the last time this happen was about 3 weeks ago. the first time the vehicle overheated on me it was about 113 degrees Fahrenheit outside and i was waiting in a Walgreens drive thru for about 20 minutes with the a/c on full blast. i made it about 3 street lights before the first (amber) warning went off and then maybe half a block after that the warning turned red and i lost about 90% control of the throttle. parked the car for a while (about 15 min) and then drove home slowly with the a/c off (i was 3 residential blocks away from home at that point). the second time it happen was a different scenario, a/c on full blast but just running errands around town (lots of stop and go traffic).

After the first overheating encounter i immediately hit the forums to see if it was common, and sure enough i was experiencing common symptoms of water pump/thermostat failure. i was in denial and blamed it on the high outdoor temperature and the fact that the car had been sitting in a drive through for about 20 min. once the second occurrence happen i accepted my fate and ordered a brand new BMW water pump (continental), BMW thermostat, BMW coolant (and 1 gallon distilled water), and a new water pump to thermostat connecting hose.. waited about a week for parts to come in and installed them the next evening (about a week ago).

I have been driving the car now for about a week with the new parts and thought i was done with the overheating mess but sure enough i was wrong. on my way home from work last night the highway was empty so i decided to step on it. after a few min of cruising at 100MPH with the a/c on full blast i begin to notice the oil temp gauge start to creep to the 250 mark (half way), it made it to 2 and a half dashes before the 250 indicator. the gauge normally sits at the half way point between the 160 and the 250 markings so it definitely began to heat up. fortunately i did not get any high temp warnings on the idrive but again i was close enough to home that i didn't really push it. i also turned off the a/c once the needle got next to the 250.

I DONT KNOW WHAT TO DO NOW PLEASE HELP... I can provide additional info about what i am experiencing if needed.


About the car:
2011 BMW 335Xi (Xdrive) E90
N55 motor w/JB4 and intake
aside from that im all stock.

[E30_335i]

Best thing I found was the Burger Motorsports cowl filters. Getting rid of the OEM cowl assembly with cabin filter opens the back of the hood up for air flow. I'm running my car on track, and those cowl filters dropped my temps down to 220 around town, and just about 250 on track.

[weehe126]

So you have not had any overheating warnings since you replaced the water pump and thermostat right? Then you are fine. Each tick mark is 10°F, so you were around 225-230 which is normal. While cruising the coolant temp will go higher to make the engine more efficient (electric water pump). So it is natural for the oil temp to follow.

[bNks334]

There isnt a direct correlation between coolant and oil temps. You need to log your actual coolant temps. There is a hidden menu in the dash if you don't have any other means. An OBII adapter and the free app torque on your phone works great too.

Once you figure out if you're coolant is actually getting too hot (I'd say anything over 107 is not normal) then you can go back to troubleshooting waterpump, thermostat, or something else. Possibly a leaking head gasket pushing exhaust gas into the coolant or an airlock causing a false positive overheating reading. You could also have poor coolant flow through the block or radiator.

Keep in mind the car should throw a code if anything is wrong with the water pump. The thermostat not working right is also an easy troubleshoot.

[opjose]

Actually on the 335i ~220F on the coolant is considered normal. 115C is the point the engine starts reducing power to prevent overheating.

The car purposely does this when in "eco" mode to maximize emissions efficiencies.
The Bentley manual lists the different temperature map ranges.

One way to check if the cooling system is working properly is to let it come up to temp, then floor the car or drive it hard. The coolant temp will GO DOWN as the electric pump kicks in to lower the temps during hard driving, frequently going to 90c or so.

For the 335i as long as you are below the halfway mark on the oil gauge you should be fine. Your system is working.

I've just been through all of this including, limp mode, swapping out pump, thermostat, etc... then thinking things had not been fixed.

335xi 2011 N55 JB4, Cobb Hi-Flow Catted DP, BMS Chargepipe

[dannyle27]

When you poured your coolant in, what steps did you take to bleed the air out of the system? Did you simply pour, tighten the cap, and drove? Did you open the expansion tank cap when it was still hot?

[dannyle27]

Originally Posted by dannyle27

When you poured your coolant in, what steps did you take to bleed the air out of the system? Did you simply pour, tighten the cap, and drove? Did you open the expansion tank cap when it was still hot?

Reason for me asking is because you have to follow these specific steps on this car:

Pour fluid, tighten cap
Switch ignition on. (Not engine)
Set heater to max temp
Set fan to lowest setting (not auto)
Step on gas pedal to floor for 10 seconds.
Wait 10-15 minutes as fan will kick on and off multiple times.

It will automatically bleed air out.

I'm not sure if you need to do it again after you open it to check fluid levels.

[Turbod]

Originally Posted by dannyle27

Reason for me asking is because you have to follow these specific steps on this car:

Pour fluid, tighten cap
Open bleed screw on coolant reservoir
Switch ignition on. (Not engine)
Set heater to max temp
Set fan to lowest setting (not auto)
Step on gas pedal to floor for 10 seconds.
Wait 10-15 minutes as fan will kick on and off multiple times.

It will automatically bleed air out.

I'm not sure if you need to do it again after you open it to check fluid levels.

Fixed

[Kjaakars]

Hello.. Does anyone know how to bleed air if i have mechanical water pump?

[weehe126]

Originally Posted by Kjaakars

Hello.. Does anyone know how to bleed air if i have mechanical water pump?

If you have a mechanical water pump you don't have an N55.

[dannyle27]

Originally Posted by Turbod

Fixed

Haha I had a feeling that I was missing something.

[OneMoreAlex]

Originally Posted by bNks334

There isnt a direct correlation between coolant and oil temps. You need to log your actual coolant temps. There is a hidden menu in the dash if you don't have any other means. An OBII adapter and the free app torque on your phone works great too.

Once you figure out if you're coolant is actually getting too hot (I'd say anything over 107 is not normal) then you can go back to troubleshooting waterpump, thermostat, or something else. Possibly a leaking head gasket pushing exhaust gas into the coolant or an airlock causing a false positive overheating reading. You could also have poor coolant flow through the block or radiator.

Keep in mind the car should throw a code if anything is wrong with the water pump. The thermostat not working right is also an easy troubleshoot.

This is just not true. I just had my radiator replaced along with the expansion tank. The only reason it was in for service was because I noticed the oil temps were higher than usual. There were no lights, warning signs, not even a noticeable leak. Had it not be for my extreme OCD about my oil temps the leak would have gone completely unnoticed.

If the coolant can not do it's job to keep the engine cool than you will certainly see higher oil temps.

[OneMoreAlex]

OP - oil temp up to 250 is considered normal. I wouldn't be surprised even if it was pinned at 250 given the outside temp you mentioned. My car was going past 250 all the way to almost 270. That's how I knew something was wrong, turned out it was the radiator and expansion tank.

I've also had my water pump go out on me at ~30k. That time the oil temps were normal but the car shot into limp mode. I wouldn't be worried unless you see oil temps higher than 250 or unless you're going into limp mode.

[terryd5150]

I'm not sure I'd be worried with oil temps at 250 when you're doing 100MPH with the air on full blast.

If you didn't actually get a temp warning, I'd think you're OK.

[turbo_chris]

Originally Posted by OneMoreAlex

This is just not true. I just had my radiator replaced along with the expansion tank. The only reason it was in for service was because I noticed the oil temps were higher than usual. There were no lights, warning signs, not even a noticeable leak. Had it not be for my extreme OCD about my oil temps the leak would have gone completely unnoticed.

If the coolant can not do it's job to keep the engine cool than you will certainly see higher oil temps.

Coolant can only affect engine/oil temps to a certain extent based on ambient temps. In the middle of the summer in hot climates where ambient temp is 100+ degree's seeing 240-250F oil temps would be considered normal. And there are a lot of factors in play when it comes to oil temps. Does the car have a oil cooler? All N55's don't have oil coolers. Is the car sitting still, driving at moderate speed, or driving on the highway? Our cars run hot on the highway to get better fuel economy. They also run hot when sitting still due to no air flow past the radiator and/or oil cooler. I regularly see 240F oil temps in the summer on my 40 min commute to work once the engine is warmed up.

Having said that. Oil temps aren't the same as coolant temps. Seeing high oil temps doesn't indicate a car that's overheating. To anyone concerned I would recommend getting the JB4 mobile app and monitoring coolant temps.

[Tony_s]

First and foremost id like to thank everyone for there suggestions to this post. i really do appreciate the help.

next, i have read all of your suggestions and im going to attempt to reply to all of them on this message (hope i dont confuse anyone). but before i begin id like to state that this is my 3rd summer owning this car (purchased 04/2014) and this is the first time i have received this type of behavior form the car. what i mean by that is, although the temperature is at its peak (110F to 120F), this isnt my cars first rodeo. it didnt behave this way the previous years and in my opinion should not be behaving this way now :\ . that logic is what leads me to believe that there is something wrong with my internal cooling system. Also, my car is parked in a garage so im sure there would be a trace of coolant if there were any leaks. And no limp mode since the 1 incident.

First, E30_335i : i dont push the car (although designed to be pushed to the limit) on a daily basis, it mostly is means of transportation, i dont believe that i should have to go and swap out a factory design just because she wants to be a little brat right now. now if i was running the car on the track routinely i would definitely agree with you.

2nd, weehe126 : No, i have not received a overheating warning yet but every day the the needle goes from 160 to about 205 (normal position) and then slowly deviates to 2 hash marks before the 250. a month ago when i did get the overheating Waring light it occurred at 250.

3rd, bNks334 : i am curious to know how exactly i should go about logging my coolant temps? i would like to try this method to get a better idea of whats going on internally. Now i am kinda skeptical towards the leaking head gasket suggestion but i am not going to rule it out completely. i must say that the vehicle is holding all the coolant with no leaks and nothing out the tail pipe. How would i go about determining if i have flow restriction through the block or radiator?

4th, opjose : the values you are providing for normal operating temperature and max temperature appear to reflect my vehicles. and i will get back to you shortly with the results for the test you suggested.

5th, dannyle27 : i poured 1 gal BMW coolant and 1 gal distilled water into the coolant reservoir while the vehicle was off and the bleed screw undone. next i capped the reservoir and put the bleed screw back on (both tightened securely) and went into my car and put key in engine off, heater on 84F and fan at lowest speed, depressed the gas (throttle) pedal for about 10-15 seconds until i heard the water pump working. waited exactly 15 min before opening the cap and adding more coolant and then repeated the process once more. i never opened the cap after starting the car or while hot.

6th, OneMoreAlex : i would like to know more about this, how exactly do i go about finding a slow leak? i will not rule out this suggestion and i am going to attempt to find out more about it.

7th, terryd5150 : i wouldn't be worried if i hadn't just changed my water pump and thermostat. but since the installation my focus has migrated from the speedo to the oil temp gauge. i mean seriously, if it weren't for the fuel reserve warning going off i would have been left on the road side stranded because i haven't paid any attention to any of the other gauges. Also, the car has been handling speeds up to 150+ in 100F weather without any issues (with a/c on full blast, just takes a little longer to get there). keep in mind that here in Las Vegas our summer nights are at + or - 100F.

and finally, turbo_chris : my vehicle is equipped with an oil cooler and i also popped in a "Sport Oil Cooler Valve" from BMS sometime last year. my brother has a 2012 550i V8 twin scroll turbo and i know they are two completely diff engines but im going to see what his normal operating temperature is and go off that (because his vehicle is submitted to the same temp,traffic, and wind conditions) untill i can get a concrete operating temperature for my car. i want to say that its a matter of time (not driving manner) that gets the needle up to the high spot.

i am going to attempt to upload some pictures of the oil temp gauges' position so you guys can see for your selves.

thanks again for all the help, hope to hear from you guys soon.

Tony..

[Tony_s]

2 pis of car running hot and the last is normal position

[weehe126]

Originally Posted by Tony_s

2 pis of car running hot and the last is normal position

Then your car was "normally" running too cool. You want it to be 210-220F so that it can evaporate any water condensation that may have collected. I'm willing to bet what you think is normal was when your thermostat failed resulting in it staying open. Keeping coolant and oil temps lower. Since it was stuck open the water pump was running full blast all the time and failed. Now that everything is new, your temps are normal.

[turbo_chris]

Originally Posted by weehe126

Then your car was "normally" running too cool. You want it to be 210-220F so that it can evaporate any water condensation that may have collected. I'm willing to bet what you think is normal was when your thermostat failed resulting in it staying open. Keeping coolant and oil temps lower. Since it was stuck open the water pump was running full blast all the time and failed. Now that everything is new, your temps are normal.

I agree. My E90 also has a oil cooler and BMS oil thermostat bypass and I run the same temps as you first 2 pics in the summer. Nothing to be concerned about. Do you have the BMS mobile app? You can monitor coolant and oil temp through that app live, but it requires a bluetooth adapter on the JB4 side.

Also, if you have a data cable you might be able to monitor the coolant temp through the jb4 interface on your computer.

[JETmn]

You are incorrect, the car should be running from 230-250. Either the car is not fully warmed up in your "normal" pic or you have a thermostat that is sticking open. My car runs 240-245 in the Florida heat this time of year (high 90's). I believe the t-stat on stock oil cooler is set to open around 230.

[OneMoreAlex]

Originally Posted by turbo_chris

Coolant can only affect engine/oil temps to a certain extent based on ambient temps. In the middle of the summer in hot climates where ambient temp is 100+ degree's seeing 240-250F oil temps would be considered normal. And there are a lot of factors in play when it comes to oil temps. Does the car have a oil cooler? All N55's don't have oil coolers. Is the car sitting still, driving at moderate speed, or driving on the highway? Our cars run hot on the highway to get better fuel economy. They also run hot when sitting still due to no air flow past the radiator and/or oil cooler. I regularly see 240F oil temps in the summer on my 40 min commute to work once the engine is warmed up.

Having said that. Oil temps aren't the same as coolant temps. Seeing high oil temps doesn't indicate a car that's overheating. To anyone concerned I would recommend getting the JB4 mobile app and monitoring coolant temps.

Okay yes I see what you're getting at, in my case though I was describing oil temps above 250. This was directly effected by the radiator leaking coolant. But the point I was trying to make is that saying the oil temp has no effect on coolant temp is false information. I would like to know where you're coming up with that analyses.

Also, yes N55 cars did come with an oil cooler. The only ones that didn't are xDrive cars to my knowledge.

Originally Posted by Tony_s

6th, OneMoreAlex : i would like to know more about this, how exactly do i go about finding a slow leak? i will not rule out this suggestion and i am going to attempt to find out more about it.

There are multiple ways you could test to see if you have a leak. The first thing I did was take the under plastic off and visually inspect for leaks. The next thing is to pressure test the system. If you're not getting any indication that you are low on coolant, chances are you probably don't have a leak. In my case I would have to refill my coolant tank every 2 weeks, that's how I knew something was wrong.

But I'd like to conclude that the temps you're seeing are nowhere near an overheating condition and this is 100% normal.

[Tony_s]

weehe126, i am going to continue driving the car and keep a close eye on the oil temp gauge since many bmw 335 owners are agreeing that the normal temp is that in the first two pictures. since the scenario you suggested where the old thermostat was probably defective is also a realistic possibility. but the part that gets me thinking is that even with the old water pump and thermostat the car only over heated when the a/c was on. im sure that if i were to not turn on the a/c on the old setup, the car would have not overheated (but i cannot test this theory anymore since new equipment was installed).

turbo_chris , i do have the jb4 with the usb cable connected to it but i dont know how to work the jb4 software on my laptop or should i say i dont know how to isolate the oil temp. it doesn't really plot a value for the temp (or maybe i just dont know how to work the software).

JETmn i am going to look into what my vehicles normal operating temp should be and go from there.

OneMoreAlex i regret to inform you that my 2011 335xi (AWD) does indeed have an oil cooler. but we agree on all N55's being equipped with an oil cooler.
i have never received any "low coolant" warnings, so then im going to assume no coolant leaks.

and i am going to temporarily accept that those are standard normal conditions for the vehicle in summer weather but ill keep a close eye on it and report any worries/symptoms here when they arise.

Thank you all for your responses.