[JayD]

08 335 - with performance steering wheel

the coolant temps listed on the steering wheel vary from 208-210 while cruising up to 225 in heavy stop/go traffic. these temps seem really high.
is this normal or do I have an issue with water pump. no leaks, no codes, and resovoir is full.

thanks
Jay

[az335iat]

Originally Posted by JayD

08 335 - with performance steering wheel

the coolant temps listed on the steering wheel vary from 208-210 while cruising up to 225 in heavy stop/go traffic. these temps seem really high.
is this normal or do I have an issue with water pump. no leaks, no codes, and resovoir is full.

thanks
Jay

No problem with water pump since temps are cool when cruising. Low airflow in stop and go traffic indicates fan problem. 250+ does sound too high to me.
Is this with the AC on and does the radiator fan come on when the AC is turned on?

[moparacker]

Those temps are completely normal.

The electric water pump and electronically controlled thermostat vary the engine temp based on driving condition.

• 112°C (233°F) ECO mode (economy)
• 105°C (221°F) Normal mode
• 95°C (203°F) High mode
• 80°C (176°F) High + mapped thermostat mode

The coolant control sets a higher cylinder head temperature (112°C) if the engine control unit determines ECO mode based on the current operating conditions. The engine is operated with relatively low fuel consumption in this temperature range as the internal friction is reduced. An increase in temperature therefore favors lower fuel consumption in the low load range. In HIGH and mapped thermostat mode, the driver wishes to utilize the optimum power development of the engine. The cylinder head temperature is therefore reduced to 80° C. This results in improved volumetric efficiency, thus increasing the engine torque. The engine control unit can therefore set a certain operating mode adapted to the respective driving situation. Consequently, it is possible to influence fuel consumption and power output by means of the cooling system. Intelligent Heat Management This concept of intelligent heat management opens up potentials for engine functions.

Basically, higher coolant temps when performance isn't needed and lower temps when performance is needed.

[az335iat]

Originally Posted by moparacker

Those temps are completely normal.

The electric water pump and electronically controlled thermostat vary the engine temp based on driving condition.

• 112°C (233°F) ECO mode (economy)
• 105°C (221°F) Normal mode
• 95°C (203°F) High mode
• 80°C (176°F) High + mapped thermostat mode

The coolant control sets a higher cylinder head temperature (112°C) if the engine control unit determines ECO mode based on the current operating conditions. The engine is operated with relatively low fuel consumption in this temperature range as the internal friction is reduced. An increase in temperature therefore favors lower fuel consumption in the low load range. In HIGH and mapped thermostat mode, the driver wishes to utilize the optimum power development of the engine. The cylinder head temperature is therefore reduced to 80° C. This results in improved volumetric efficiency, thus increasing the engine torque. The engine control unit can therefore set a certain operating mode adapted to the respective driving situation. Consequently, it is possible to influence fuel consumption and power output by means of the cooling system. Intelligent Heat Management This concept of intelligent heat management opens up potentials for engine functions.

Basically, higher coolant temps when performance isn't needed and lower temps when performance is needed.

Good info!

[Indo Rider]

Great info! Hope you're around to answer more random questions so well!

[moparacker]

I'm always lurking.

[mzman]

Originally Posted by moparacker

I'm always lurking.

That is great info, where did you find that at? The cooling system on this car is way more advanced the my other cars so It's a bit of a black box for me at the moment. This really sheds some light.

[lecsoman]

I have 118 clesius water easy on a hotter day and after 2-3 accelerations. I have an AT, so the water cooler also cools the trans, which meakes me way to hot. Even with the ER oil cooler kit, i reach also 270F oil really easy. ON a track, specially a slower one this would mane probably over 120 celsius water and over 275F oil easy.

Limp mode kills me in a minute...

Is there any solution for the way to hot AT car that i have?

[lecsoman]

I see some posts on e90post about this, but they stop after a while and it seems the team who wanted to make a better water cooler for AT cars never made it since they needed to make 5 parts at least, and that never happened.

ENRITA do you have a solution?

[bnk]

Auxiliary radiator by BMW

[lecsoman]

Originally Posted by bnk

Auxiliary radiator by BMW

It dose not fit, i have a ER competition oil cooling kit...

[lecsoman]

I googled around and talked to some drift car and race car builders here about the the N54 AT water overheat problem.

We AT car owners need to solve the heat issue or on the track or our car limits us badly, this is a known fact now for AT N54 users i think. I would say those who don't have limp mode on the track with AT cars are unbelievable lucky or they never drive as hard as they could with this car. For me to avoid limp mode i have to take back more than 50% of my driving style, even if Max Cool is ON and with a system filled with 10/90 cooling fluid and 2 bottles of Mo Cool. Also i have the ER oil cooling kit, which seems to solve the oil temp problem, but it dose not help by the water enough.

Since the problem is generated by the transmission using the water cooling also to get the transmission oil temps down we have according to others already trying to solve this problem 14% less size water cooler, and the trans using this already smaller cooler to stay cool also.

First solution would be to separate the trans cooling from the engine cooling, but the trans needs this cooling, so the water + trans oil cooler BMW solution i guess must stay the same way together.

Now i could go and install the Meth kit, to draw some heat from the engine or instal a more open hood, to get a better air flow, or change small things here and there to try to get a few degrees lower heat in or near the engine, but i simple will tackle the problem where its generated, by the water + trans oil cooler.

I'm going next week to cooler builders and i will make a custom water + trans oil cooler which is going to be bigger and more efficient and install it with maybe the 850W ventilator.

Hopefully i will find someone who is willing to do this with me, and i will keep people updated about it!

(P.S. I think the turbo plays also a big part in limp mode beacuse of to high water temps, but i did not see any info anywhere about an AT car owner seeing better water temps after an RB install. So i don't know if or if not the RB would solve this water temp problem. If it would, than thats by far better solution than what i will do now!)

[b1aze]

Weren't you the one using 20w-60 oil? Proper lubrication of the internals will surely reduce your water temps. You could also try wrapping your coolant lines in cold-gold heat wrap so that the engine bay temps don't heat soak your coolant coming from the outlet of the radiator.

It would be interesting to see what sort of cooling efficiency you get with your specific car. I have nothing to baseline it against but you really shouldn't be running that hot. If you could find a way to probe your inlet and outlet coolant temps from your radiator, that may tell us if it's your engine that's running far too warm or your radiator is not efficient enough.

[lecsoman]

20w60 is a proper lubricant for this car, anyone who has a bit to much oil usage can use this oil safely, also people who track there cars really often can also use this oil with out any issues. I see this oil being used by 400-600 whp turbo charged drift cars.

Anyway i followed the advices of the people here and changed the oil to 5w40. Nothing changed by any of my temps.

Than i asked around for more such advice and changed the coolant to 10% cooling fluid 90% water and 2 bottles of Mo Cool. Temps did not change a bit.

What dose change temps is the Max Cool ON by the JB4. Or if the sun dose not shine and the out side temps go down.

I don't really want to try alternatives routes. I will for sure measure the incoming water temp and the outgoing water temp of the radiator. But to be honest i wont really find anyone knowing if thats the right temp or not. We will also measure the temp of the radiator in multiple places, and finally i will check the incoming and outgoing temp of the trans oil.

And according to what i read my car seems to be normal, 17-14psi track like driving, 2 minutes and limp mode is there. You see people write this every other day on forums.