All,

I've got a scan gauge and thought that this reading indicated that the motor was a little hot. Thoughts? My M3 runs about 25 degrees cooler...

Thanks,

Jeff

 

yes thats normal, it will go up to 220 sometimes.

 

My marshall gauge's show around 217 normal op temps

 

Yes, this has been discussed numerous times.

Most of them run around 220.

If you run with the a/c on max, you will see much lower temps though...it forces the thermostat open.

 

Why so warm?

 

cuz it's a turbo car :P

and (assuming our cars' turbo is water AND oil cooled) a turbo spinning at 900,000 rpms is going to generate quite a bit of heat... so if our cars' turbos are water and oil cooled then i'm surprised it's not higher hahaha

 

Well, my non-Turbo Just'a Cooper also runs 220f.

 

Alot of the energy in a gallon of gasoline is lost to the radiator and out the exhaust pipe. Reducing the heat rejected to the radiator increases efficiency = better gas milage. Turbo or no turbo - the concept is the same.

 

Ok, guess I should be more specific so I don't get dumb answers... gaw, I'm not really sure I understood yer broken english, lol. (jk)

Why is the t-stat set so high?

 

I think they run hot for better efficiency of fuel. That and; well, direct injection actually cools the combustion chamber cooler. I think that by running the engine hotter it helps to make up for the drop in combustion temperature.

I've gotten a little queesy seeing 225 on my scangauge.

 

It makes me wonder if swapping to a lower thermostat, say a 195 degree, could allow to you to run a bit more boost?

 

the R56 doesnt have a thermostat, its temp is controled by the ECU

 

How?

 

I will have to let someone with more knowledge than me answer that, but there is no thermostat as you are used to them being.

 

Mine runs 222 to 225F. Never seen it say as low as 217F.

 

Flip the a/c on max and watch the temps plummet below 200

 

OK, I'll get even more nerdy with a formula or two


High coolant temp = better gas mileage and lower emissions

Better gas mileage = happy owners and more bragging rights

Better gas mileage = Al Gore is actually in a good mood

More bragging rights and high EPA mileage figures = more sales

More sales = happier BMW management

Happier BMW management = hood scoops that don't melt (nah-jk)

Low coolant temp = lower gas mileage but calmer drivers

 

High coolant temps mean its running lean, hence the better gas mileage, yet which is NOT good for a boosted vehicle. A hot motor is also wasted energy, which also means hot intake temperature which evidently isn't a good things since we have these little things called intercoolers to counter act that very problem which also seems to be one of the few major performance gains of these car said by many. Making these motors run a little cooler usually reaps performance gains.

I appreciate it if you keep your counter productive remarks to yerself since I'm legitimately trying to figure this out.

 

+1 but because it is controlled by our ECU I don't see us having the option to lower the temps any time soon.

 

Alright the part that looks like a artificial Heart is the Thermostat housing/Thermostat (4). The issue some may be seeing is a miss-read on the sensor as in the motor is getting warm too fast for the normal running parameters that are set in the cooling level table in the ECU.

 

LiLReD1 writes: "High coolant temps mean its running lean, hence the better gas mileage, yet which is NOT good for a boosted vehicle. A hot motor is also wasted energy, which also means hot intake temperature which evidently isn't a good things since we have these little things called intercoolers to counter act that very problem which also seems to be one of the few major performance gains of these car said by many. Making these motors run a little cooler usually reaps performance gains."

A lean engine runs hotter than a rich engine but the coolant temp does not necessarily go up IF the cooling system has the extra cooling capacity. Modern cars typically run much hotter than older cars to increase engine efficiency. For the coolant to be at a lower temperature more heat has to be dumped to the radiator and this heat came from burning fuel.

Agreed that a hot intake air is bad for power and can increase the possibility of predetonation. Intercoolers cool the combustion air down to compensate for compressing it in a turbocharger which raises its temp. What we are trying to do is get as much oxygen as we can in the engine and a cooler charge has more oxygen allowing the engine to burn more fuel and make more power. Adding a larger intercooler to further reduce the air charge temperature can make more power -but it has nothing to do with coolant temperature. This is why a non-turbo engine has noticably more power in cold weather - more oxygen to the engine.

Modern engines can withstand the higher coolant temperatures because of improved oils and better production tolerances among other reasons. Cooler runnning engines have more difficulty passing emmision standards and this is another reason coolant temps have gone up.

Finally, as a mechanical engineer and a car enthusiast I was sincerely trying to help and offer an explanation to your question in my first post. I assumed from your comments to my initial post that you liked to kid around.

 

No, I was legitimately asking, lol. I appreciate the "normal" response though, even though I know that stuff.

Again, it still doesn't really answer my question, but I guess nobody really knows until we have a MINI engineer chime in.

To me, 215*-225*, even in the modern day of "warmer" running engines, still seems kind of high. I'm not knowledgeable of all the running temps in todays modern cars, but I usually only see motors run from 200*-210*... MAYbe 215* in my experience. My SRT-8 and HEMI truck ran in the 207*-212*, and it's not out of the ordinary to see 195 or 180 t-stats as a mod for those as an increase in power. The SRT-8's had a big problem with heat soak as well.

 

I think "gawannamini" already answers your question. you're just not paying attention. engineers on minis went to 215-225F because thats the temperature this engine can get the maximum efficiency (dont worry it can reach up to 250F) try to put something that make this engine run cooler, and see if it will pass smog . If you are trying to compare it to a japanese car, or worried because normal engine temp range from 185-195F put a Honda V-tec engine in it. That is why Minidealer shop (where I used to work) they DO NOT recommend upgrading this engine because it was set up to the max.

 

No, I don't think he did... yes that's the temp they give it for maximum efficiency, but what is it about this engine that makes it run more efficient with the hotter temps when in my experience a cooler running engine is more efficient. Efficient I mean by better mileage, not low emissions.

I don't recall ever saying I was worried, or wanting to put a japanese motor in it, or even comparing it to one. Last I recall, a HEMI was american? And of course any dealer won't recommend upgrading any engine unless they sell the parts for it. But of course I didn't just get a coupon in the mail to upgrade an S with the JCW package. (Looks like my dealer wants me to upgrade.)

And I'm not sure what you mean by setup to the "max". No manufacture will do that cause that leaves no room for error in mass production.

 

LiLReD writes: "...., but what is it about this engine that makes it run more efficient with the hotter temps?"

That''s a key point. Nothing is special about this engine that makes it more efficient at higher temperatures. It is thermodymanic law. Less energy dumped to the radiator = more energy to the wheels - applies to all internal combustion engines.

Of course, there is a temperature limit or we melt our engines. The materials we use to build engines can only take so much. So we have to accept quite a bit of inefficiencies (heat out of the tail pipe, heat dumped to the radiator, heat dumped to the oil cooler etc.)