Quote:
Originally Posted by johnmyster
The goal wasn't to run cooler. I wanted to see better regulated oil temps, as I imagined BMW did when they put these heat exchangers on other n52 applications. With no dedicated oil cooling whatsoever, transient oil temps seem pretty decoupled from water temps...especially for a motor with a complicated valvetrain and tight specs on oil performance.
This n52 technical documentation says that the engine has four different temperature profiles. I notice the highest temperatures (water ~215 F) are maintained during steady highway cruising. The lowest (water ~180 F and sometimes lower) seems to be for "spirited" and stop/go efforts. I imagine the BMW engineer types are smart enough to preference high temperatures for economy, crankcase cleanliness, etc. I notice my engine swings between "modes" pretty quickly, so I don't think the engine is under cooled (in terms of radiator or coolant flow) for my needs.
I doubt the water pump would be completely off during warm-up conditions. Some flow would (even with thermostat/radiator flow closed) would be necessary to warm the block up evenly and give flow to the heater core...and would provide flow to any such ancillary coolers (engine/trans/etc) that are fitted.
Further insight into how the engine management program controls temp via combined thermostat, e-fan, and water pump control would be interesting topic...one I'm sure haasmachine has looked into. |
Interesting... thanks for taking the time to write up on your experience with this project.
The car runs hottest during highway trips To increase fuel efficiency and help with emissions. There is absolutely no other reason why these vehicles need to run so hot as it only hurts performance when oil temp rises past 100c.
I know that the car has these profiles, but the oil temp just always seems to be between 110c-120c regardless of what sort of driving I'm doing unless it's simply Cold outside. I notice that the engine runs and performs better at the 100c mark which is the temp I wish I could maintain in the summer too, not just during cold weather. I've been debating to fabricate a custom hood for the summer to help extract hot air underneath the hood and increase radiator flow, as I'm not sure how else I can lower temps without installing an oil cooler.
My biggest concern is not only the affected performance, but these high temperatures Calls for good quality oil that must be strongly resistant to shear. The oil that most of us use, and the lengthy oil change intervals are not helping.