BMS Low Temp Thermostat

Pig Farmer · 04-28-2013, 02:09 PM

In the never ending quest to improve the N54's cooling, I recently installed the BMS Low Temp thermostat. I should point out that it's not really a thermostat for the reason it directs oil through the oil cooler at all times and never closes.

For a point of reference, I'm running the PPK2 auxiliary radiator and fan, plus an ER sport oil cooler (with the original core replaced with a Setrab core) and running Castrol 5w-30. I'm also running a Cobb tune with 18.5 psi of boost. My observations were in 80-85 degree weather.

Prior to installing the BMS thermostat, my temps would hover around 240 degrees and climb to 245 when driving briskly on the street. When I originally installed the oil cooler, my temps were probably 10 degrees lower, so i suspect that the OEM thermostat was aging and not opening properly. When i pulled the OEM thermostat, I noticed wear on the brass piston so maybe it was getting hung up?

After installing the BMS thermostat, I have yet to see oil temps above 220. This includes several, several back to back pulls and 45 minutes of stop and go traffic with the a/c running on the max setting. On the highway, the oil temps drop to between 205 and 210. Needless to say the water temps are about 10 degrees lower on average as well Only time will tell, but so far I'm pretty happy with the results. I finally feel that the oil cooler is getting fully utilized. Just need to get use to where the needle comes to rest on the oil temp gauge.

Pyrat 2 · 04-28-2013, 02:54 PM

I have an n55 and am regularly running 245ish once warmed up and in normal traffic. I am concerned a bit with what will happen when I'm at the track. My car is new and I haven't gotten it there yet. While I'm very intrigued by the results here and posted elsewhere, I do have to ask why BMW has the thermostat set at the temperature they do? They could easily have put in a different temperature thermostat or none at all. I can speculate that it is for emissions reasons but certainly would like a definitive understanding of the trade off of running cooler.

Also, curious as to how you know your coolant is running 10 degrees cooler?

Pig Farmer · 04-28-2013, 03:12 PM

Quote:

Originally Posted by HeelToe

I have an n55 and am regularly running 245ish once warmed up and in normal traffic. I am concerned a bit with what will happen when I'm at the track. My car is new and I haven't gotten it there yet. While I'm very intrigued by the results here and posted elsewhere, I do have to ask the question of why BMW has the thermostat set at the temperature they do. They could easily have put in a different temperature thermostat or none at all. I can speculate that it is for emissions reasons but certainly would like a definitive understanding of the trade off of running cooler.

Also, curious as to how you know your coolant is running 10 degrees cooler?

My understanding is that the higher operating temperature allows for improved fuel economy but comes at the cost of lost performance. The car is actually equipped with a coolant temperature sensor but no gauge... Go figure. I'm pretty sure a number of the tune allow you to read/log your coolant temps but i'm reading mine off a P3car gauge (a pretty slick little piece of electronics that should come stock).

Everfly · 04-28-2013, 03:18 PM

Nice. I should get one for my N55

Stan.mac · 04-29-2013, 08:43 AM

I know that oil cooling has nothing to do with heat saturation within the IC, but have you noticed a difference in heat soak?

MGallop · 04-29-2013, 01:15 PM

im def. getting one!

Pig Farmer · 04-29-2013, 05:00 PM

Quote:

Originally Posted by 011100001

I know that oil cooling has nothing to do with heat saturation within the IC, but have you noticed a difference in heat soak?

I haven't seen a noticeable change in the IATs and I wouldn't call this a substitute for a larger more efficient FMIC, but the engine seems to run a bit smoother at the new lower temps.

If by heat soak you mean triggering limp mode from elevated oil and/or coolant temps, I haven't been remotely close to those temps.

Stan.mac · 04-29-2013, 06:39 PM

^ Ok; I jut wasn't sure if this would have an effect on FMIC heat soak.

int2str · 04-29-2013, 07:46 PM

I've been thinking about getting one.

But I'm concerned that this means that the car never really gets up to "operating temperature". Especially on short trips. You need some temperature to get the oil to flow everywhere it should and not sludge up the engine.

So yes, I'd be a little concerned about this.

Dackelone · 04-29-2013, 08:17 PM

Quote:

Originally Posted by int2str

I've been thinking about getting one.

But I'm concerned that this means that the car never really gets up to "operating temperature". Especially on short trips. You need some temperature to get the oil to flow everywhere it should and not sludge up the engine.

So yes, I'd be a little concerned about this.

+1. Don't you guys think BMW knows a thing or two about building engines? After all "motor" is their middle name/initial! Just because your oil temps are lower doesn't mean its a good thing. I too would be concerned with sludge. Your oil or cooling system needs a thermostat. I would never think of deleting it. To each their own.

Eddie135 · 04-29-2013, 08:38 PM

Quote:

Originally Posted by Dackelone

+1. Don't you guys think BMW knows a thing or two about building engines? After all "motor" is their middle name/initial! Just because your oil temps are lower doesn't mean its a good thing. I too would be concerned with sludge. Your oil or cooling system needs a thermostat. I would never think of deleting it. To each their own.

+1

Stan.mac · 04-29-2013, 09:30 PM

I'll say +1 because he does make a valid point; then again that can be said about everything, so why mod?
One could use that very debate about HP gains... IMO

Pig Farmer · 04-29-2013, 09:46 PM

If you use your car to simply commute from point A to point B, you're probably fine with the how the car came from the factory. If you ask more of your car than what it was designed for, you're always chasing the next weak link. This is what some of us do and one of the reasons this site exists. We get an exhaust, then a tune, then a FMIC, then downpipes, a charge pipe, cooling, non-RFTs, sway bars, coilovers, LSDs, big brake kits, and so on. I surely wasn't trying to start a debate or suggesting that everyone replace their thermostat, i was just sharing my observations. Feel free to do whatever you think is best for you and your car.

int2str · 04-30-2013, 12:36 AM

Farmer, I just finished installing the competition oil coolers from ER since my car kept overheating on the track. I'm not arguing against modding or the requirement for additional cooling.

I'm just not convinced that this thermostat doesn't do a lot more harm than good...

Mike@N54Tuning.com · 04-30-2013, 06:07 AM

Quote:

Originally Posted by int2str

I've been thinking about getting one.

But I'm concerned that this means that the car never really gets up to "operating temperature". Especially on short trips. You need some temperature to get the oil to flow everywhere it should and not sludge up the engine.

So yes, I'd be a little concerned about this.

Warmup is delayed a minute or two but the oil temperature still runs in the ~210f (~100c) zone considered ideal by most engine builders.

Mike

Qbrozen · 04-30-2013, 08:56 AM

Quote:

Originally Posted by Dackelone

Don't you guys think BMW knows a thing or two about building engines? After all "motor" is their middle name/initial!

I can see both sides of this argument. Yes, their engineers are much more experienced with the engine they designed and built. On the other hand, if they had it all figured out, why did early N54s come with no oil cooler? And then, even after adding one, why do stock vehicles go into limp mode when pushed hard? And what about the HPFP failures? You could go on and on from either side of the fence.

spain4065 · 05-03-2013, 03:54 AM

Just installed one in my 08 135i. Talk about a noticeable drop in temp, went from 240 after constant pulls to 210-215 on a regular basis. Easy, simple install and very cost effective!

Pig Farmer · 05-03-2013, 07:18 AM

For all those people thinking it takes forever to warm up, I timed it last night. The car was completely cold before the drive and it was 68 degrees outside. I drove approximately 1.5 miles to the freeway and held the car at 70mph once on the freeway. RPMs were kept below 2,200 and the intake manifold was in a vacuum the whole time. It took a little over 5 minuntes (or five miles) for the needle to move. The oil reached 180 in 7 minutes, and 205 in ten minutes where it held constant.

Keep in mind I'm running an aftermarket oil cooler with an additional quart of oil capacity.

Here's an idea... Could someone with the OEM thermostat perform the same test and post the results?

04-28-2013, 02:09 PM	#1
Pig Farmer Major 340 Rep 1,293 Posts Drives: E92M Join Date: May 2010 Location: Florida iTrader: (0)	BMS Low Temp Thermostat - Preliminary Results In the never ending quest to improve the N54's cooling, I recently installed the BMS Low Temp thermostat. I should point out that it's not really a thermostat for the reason it directs oil through the oil cooler at all times and never closes. For a point of reference, I'm running the PPK2 auxiliary radiator and fan, plus an ER sport oil cooler (with the original core replaced with a Setrab core) and running Castrol 5w-30. I'm also running a Cobb tune with 18.5 psi of boost. My observations were in 80-85 degree weather. Prior to installing the BMS thermostat, my temps would hover around 240 degrees and climb to 245 when driving briskly on the street. When I originally installed the oil cooler, my temps were probably 10 degrees lower, so i suspect that the OEM thermostat was aging and not opening properly. When i pulled the OEM thermostat, I noticed wear on the brass piston so maybe it was getting hung up? After installing the BMS thermostat, I have yet to see oil temps above 220. This includes several, several back to back pulls and 45 minutes of stop and go traffic with the a/c running on the max setting. On the highway, the oil temps drop to between 205 and 210. Needless to say the water temps are about 10 degrees lower on average as well Only time will tell, but so far I'm pretty happy with the results. I finally feel that the oil cooler is getting fully utilized. Just need to get use to where the needle comes to rest on the oil temp gauge.
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04-28-2013, 02:54 PM	#2
Pyrat 2 Colonel 1421 Rep 2,560 Posts Drives: Rapidly from A to B Join Date: Jun 2005 Location: Chicago 'burbs or TN Smokies iTrader: (3) Garage List 2022 Porsche GT4 [9.64] 2018 Porsche GT3 [9.33] 2007 Z4 M Roadster [8.33] 2020 BMW X1 [0.00]	I have an n55 and am regularly running 245ish once warmed up and in normal traffic. I am concerned a bit with what will happen when I'm at the track. My car is new and I haven't gotten it there yet. While I'm very intrigued by the results here and posted elsewhere, I do have to ask why BMW has the thermostat set at the temperature they do? They could easily have put in a different temperature thermostat or none at all. I can speculate that it is for emissions reasons but certainly would like a definitive understanding of the trade off of running cooler. Also, curious as to how you know your coolant is running 10 degrees cooler? __________________ '07 Z4MR '22 GT4 '18 GT3 '16 GT4, '16 M2, '14 X1, '13 135is, '06 330i, '03 323 Ci, '01 330i, '99 M3 (RIP), '96 318is, some non-BMWs
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04-28-2013, 03:18 PM	#4
Everfly Brigadier General 155 Rep 3,143 Posts Drives: BMW Join Date: Apr 2011 Location: Indianapolis iTrader: (51)	Nice. I should get one for my N55
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04-29-2013, 08:43 AM	#5
Stan.mac Second Lieutenant 9 Rep 296 Posts Drives: 135i M-Sport Join Date: Aug 2012 Location: NoVA iTrader: (3)	I know that oil cooling has nothing to do with heat saturation within the IC, but have you noticed a difference in heat soak? __________________ "I live my life a quarter mile at a time. Nothing else matters: not the mortgage, not the store, not my team and all their bullshit. For those ten seconds or less, I'm free." afe DCI/Greddy Oil Catch Can/Catless DP/ Cobb Stage 2+/Berk Axle-Back(Race)/AAW CP w BOV/H&R Springs/ ALPINA Flash/Helix FMIC/
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04-29-2013, 01:15 PM	#6
MGallop Major 49 Rep 1,072 Posts Drives: 12' 135i Join Date: Feb 2011 Location: San Jose, California iTrader: (1) Garage List 2012 BMW 135i [10.00]	im def. getting one! __________________ Matthew Gallop: '12 N55 Mods: JB4 Flex ISO \| iCarbon DP \| VRSF 5" FMIC \| BMS Intake \| ER Charge Pipe \| Race Axleback \| ST Coils \| Alufelgen CS7's \| iCarbon 3 fin Diffuser \| Blackline LCI \| CarbonFiber Spoiler \| Orion v4 AE's \| 30% tint \| red+blk roundels \| Cyba Scoops \| H-Style front Lip \| WeissLicht LED Smoked Sidemarkers \| Matte Grills \| Coded \|
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04-29-2013, 06:39 PM	#8
Stan.mac Second Lieutenant 9 Rep 296 Posts Drives: 135i M-Sport Join Date: Aug 2012 Location: NoVA iTrader: (3)	^ Ok; I jut wasn't sure if this would have an effect on FMIC heat soak. __________________ "I live my life a quarter mile at a time. Nothing else matters: not the mortgage, not the store, not my team and all their bullshit. For those ten seconds or less, I'm free." afe DCI/Greddy Oil Catch Can/Catless DP/ Cobb Stage 2+/Berk Axle-Back(Race)/AAW CP w BOV/H&R Springs/ ALPINA Flash/Helix FMIC/
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04-29-2013, 07:46 PM	#9
int2str Captain 80 Rep 655 Posts Drives: 2008 135i Join Date: Feb 2010 Location: San Diego, CA iTrader: (2)	I've been thinking about getting one. But I'm concerned that this means that the car never really gets up to "operating temperature". Especially on short trips. You need some temperature to get the oil to flow everywhere it should and not sludge up the engine. So yes, I'd be a little concerned about this.
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04-29-2013, 09:30 PM	#12
Stan.mac Second Lieutenant 9 Rep 296 Posts Drives: 135i M-Sport Join Date: Aug 2012 Location: NoVA iTrader: (3)	I'll say +1 because he does make a valid point; then again that can be said about everything, so why mod? One could use that very debate about HP gains... IMO __________________ "I live my life a quarter mile at a time. Nothing else matters: not the mortgage, not the store, not my team and all their bullshit. For those ten seconds or less, I'm free." afe DCI/Greddy Oil Catch Can/Catless DP/ Cobb Stage 2+/Berk Axle-Back(Race)/AAW CP w BOV/H&R Springs/ ALPINA Flash/Helix FMIC/
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04-29-2013, 09:46 PM	#13
Pig Farmer Major 340 Rep 1,293 Posts Drives: E92M Join Date: May 2010 Location: Florida iTrader: (0)	If you use your car to simply commute from point A to point B, you're probably fine with the how the car came from the factory. If you ask more of your car than what it was designed for, you're always chasing the next weak link. This is what some of us do and one of the reasons this site exists. We get an exhaust, then a tune, then a FMIC, then downpipes, a charge pipe, cooling, non-RFTs, sway bars, coilovers, LSDs, big brake kits, and so on. I surely wasn't trying to start a debate or suggesting that everyone replace their thermostat, i was just sharing my observations. Feel free to do whatever you think is best for you and your car.
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04-30-2013, 12:36 AM	#14
int2str Captain 80 Rep 655 Posts Drives: 2008 135i Join Date: Feb 2010 Location: San Diego, CA iTrader: (2)	Farmer, I just finished installing the competition oil coolers from ER since my car kept overheating on the track. I'm not arguing against modding or the requirement for additional cooling. I'm just not convinced that this thermostat doesn't do a lot more harm than good...
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05-03-2013, 03:54 AM	#17
spain4065 First Lieutenant 18 Rep 303 Posts Drives: EM1 and 08 135i Join Date: Sep 2012 Location: DC/MD iTrader: (1)	Just installed one in my 08 135i. Talk about a noticeable drop in temp, went from 240 after constant pulls to 210-215 on a regular basis. Easy, simple install and very cost effective!
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05-03-2013, 07:18 AM	#18
Pig Farmer Major 340 Rep 1,293 Posts Drives: E92M Join Date: May 2010 Location: Florida iTrader: (0)	For all those people thinking it takes forever to warm up, I timed it last night. The car was completely cold before the drive and it was 68 degrees outside. I drove approximately 1.5 miles to the freeway and held the car at 70mph once on the freeway. RPMs were kept below 2,200 and the intake manifold was in a vacuum the whole time. It took a little over 5 minuntes (or five miles) for the needle to move. The oil reached 180 in 7 minutes, and 205 in ten minutes where it held constant. Keep in mind I'm running an aftermarket oil cooler with an additional quart of oil capacity. Here's an idea... Could someone with the OEM thermostat perform the same test and post the results?
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