[Dinosoar]

Okay, did some research (not exhaustive), nothing conclusive about what the purpose of BMW engine covers are.

Reasons I've seen include: noise reduction (I believe this to be true), protect from dirt/dust (BS...my engine's filthy), routing air for cooling (sounds weird), trapping heat for controlled temps (sounds odd), and finally, looks nice (agreed, but...very subjective).

I heard of one BMW mechanic (connected to Scotty Kilmer's site) who felt it traps heat to the detriment of the engine and it is for looks and injector noise...hence removed. I've heard this from others too, but I also hear it is critical to the functioning of the engine or they wouldn't have it in the first place.

I feel this debate is like the oil debate, never gonna have an authoritative answer. Though, I recognize it is not nearly as important as oil...in fact, not that important at all. All that said, however, is there anyone who's aware of authoritative insights on BMW engine cover utility?

IMO, it's for looks and noise, nothing else. The majority of BMW buyers appreciate both, so I see why BMW would do it. I am sure this group has stronger opinions, or at least care to know.

Thoughts?

[Rdurty2]

Looks and to damper the awful noise from the injectors so every owner doesn’t start to freak out.

Nothing more nothing less. Engines are ugly to the common folk so car companies cover them in plastic to make them look “nicer”

[Dinosoar]

Originally Posted by Rdurty2

Looks and to damper the awful noise from the injectors so every owner doesn’t start to freak out.

Nothing more nothing less. Engines are ugly to the common folk so car companies cover them in plastic to make them look “nicer”

I agree...though I don't know this to be true. I took mine off and will track oil temps to see if they run slightly lower. I heard one guy claim he saw such a difference. I find it hard to believe, but will run the "test" nonetheless.

[ZM240i]

For looks …….. anything positive after that is gravy.

[Rdurty2]

Originally Posted by Dinosoar

I agree...though I don't know this to be true. I took mine off and will track oil temps to see if they run slightly lower. I heard one guy claim he saw such a difference. I find it hard to believe, but will run the "test" nonetheless.

If you take the hood off things will be cooler.

You are splitting hairs here. Nothing magical happens removing that thin piece of plastic.

[danallxt]

yup, this is kinda ridiculous
but if you are gonna run a "test" better make sure all the variables are the same:
ambient air temp same
air density the same
run time the same
if driven, drive exactly the same route, same distance, exactly the same throttle applications etc otherwise your test is totally invalid.
Also my BMW oil temp gauge is a bar graph type that is not exact enough for any comparison...i miss the digital oil temp readout of my previous vehicle.

[Dinosoar]

Originally Posted by danallxt

yup, this is kinda ridiculous
but if you are gonna run a "test" better make sure all the variables are the same:
ambient air temp same
air density the same
run time the same
if driven, drive exactly the same route, same distance, exactly the same throttle applications etc otherwise your test is totally invalid.
Also my BMW oil temp gauge is a bar graph type that is not exact enough for any comparison...i miss the digital oil temp readout of my previous vehicle.

Okay, I'll do my best to meet the U.S. Department of Weights & Measures' "dead on balls accurate" standard.

[danallxt]

excuse me for trying to be helpful, but if you don't take into account what i mentioned your so called test is a total waste of time and misleading.
your concern about oil temp and engine cover is ridiculous anyway.

[AWcoupe]

Originally Posted by Dinosoar

Okay, I'll do my best to meet the U.S. Department of Weights & Measures' "dead on balls accurate" standard.

Joe Pesci: “Dead on balls accurate?”
Marisa Tomei: “It’s an industry term”
My Cousin Vinny leaky faucet scene. CLASSIC

[Dinosoar]

Originally Posted by danallxt

excuse me for trying to be helpful, but if you don't take into account what i mentioned your so called test is a total waste of time and misleading.
your concern about oil temp and engine cover is ridiculous anyway.

Oh, I believe you were trying to be helpful. Just don't know why you throw in a dash of "rude" with your advice. It's not a serious endeavor, just a question to garner people's knowledge on it, that's all. It's not ridiculous, just a conversation. You should be nicer, even on the Internet. Thanks for your concern, though.

[XC3LLR8]

Next time I get to Davis Monthan AFB my son and I are swapping our engine covers. I'll report back if my engine runs cooler/hotter with a Toyota Supra cover.

[ggggbmw]

The cover does quiet the loud DI fuel injectors quite a bit. My wife's old Focus had DI injectors without a cover, and you could hear them in the cabin they made such a racket. Take the cover off your car and you'll hear the loud ticking.

The other purpose of the cover is actually to hold heat in. This sounds stupid, but heat management in the engine is part of the emissions control. The engine runs way cleaner and more efficiently once it is at operating temperature. When you stop the car, the cover helps to hold the heat in so that when you restart it it is closer to operating temperature. The electric water pump and thermostat are very efficient at cooling the engine in normal operation, so it doesn't add heat to the engine. The water cooling is way more effective than any convective heat loss without the cover while running.

Does holding that extra heat in cause damage to other components? Especially if driven hard or in a hot environment? Well, you could argue that, but I'm not sure it makes much of a difference. In our cars there isn't much under the cover. And you could argue that rapidly changing/cooling temps without the cover could cause issues also. (Now one of the hot-vee V8 engines is a different story.)

And yes, the cover is also there for cosmetic reasons. Although the only people who actually open their hoods these days would rather probably see the raw engine parts. (Like me.)

[Dinosoar]

Originally Posted by XC3LLR8

Next time I get to Davis Monthan AFB my son and I are swapping our engine covers. I'll report back if my engine runs cooler/hotter with a Toyota Supra cover.

I've been tracking my oil temp gauge a long time now and I have not noticed any change.

I talked to my Genius about it...he confirmed a few things. Yes, it's just for noise muting, and looks. He said while it may affect heat build-up, it would not be noticeable in the gauges when there's active oil-cooling like in both the B48 and B58 motors...same with water, of course. He said it would merely, then, have to turn on less. Makes sense.

So, I did weigh the B48 cover in at 3.5 lbs. I assume a B58 cover is easily over 5lbs....so, for us fanatics, taking weight off the front axle is good! Two, it may ease temps and cooling, and third, the cover will be it great shape when it goes back on for selling it.

[Dinosoar]

Originally Posted by ggggbmw

The cover does quiet the loud DI fuel injectors quite a bit. My wife's old Focus had DI injectors without a cover, and you could hear them in the cabin they made such a racket. Take the cover off your car and you'll hear the loud ticking.

The other purpose of the cover is actually to hold heat in. This sounds stupid, but heat management in the engine is part of the emissions control. The engine runs way cleaner and more efficiently once it is at operating temperature. When you stop the car, the cover helps to hold the heat in so that when you restart it it is closer to operating temperature. The electric water pump and thermostat are very efficient at cooling the engine in normal operation, so it doesn't add heat to the engine. The water cooling is way more effective than any convective heat loss without the cover while running.

Does holding that extra heat in cause damage to other components? Especially if driven hard or in a hot environment? Well, you could argue that, but I'm not sure it makes much of a difference. In our cars there isn't much under the cover. And you could argue that rapidly changing/cooling temps without the cover could cause issues also. (Now one of the hot-vee V8 engines is a different story.)

And yes, the cover is also there for cosmetic reasons. Although the only people who actually open their hoods these days would rather probably see the raw engine parts. (Like me.)

I have wondered about protecting some of the electrical lines if there was a lot of water splashing up in there. It does NOT work to keep dirt out though...my engine had enough dirt in there. Though, now that it is off, I may see more, huh? At least keeping it clean myself will be easier. I'm sure I look weird to my neighbors vacuuming and wiping down my engine.

[Invisiblename]

Originally Posted by Dinosoar

I've been tracking my oil temp gauge a long time now and I have not noticed any change.

I talked to my Genius about it...he confirmed a few things. Yes, it's just for noise muting, and looks. He said while it may affect heat build-up, it would not be noticeable in the gauges when there's active oil-cooling like in both the B48 and B58 motors...same with water, of course. He said it would merely, then, have to turn on less. Makes sense.

So, I did weigh the B48 cover in at 3.5 lbs. I assume a B58 cover is easily over 5lbs....so, for us fanatics, taking weight off the front axle is good! Two, it may ease temps and cooling, and third, the cover will be it great shape when it goes back on for selling it.

You believe what a BMW ‘Genius’ told you? 🥴🤣

[Dinosoar]

Originally Posted by Invisiblename

You believe what a BMW ‘Genius’ told you? 🥴🤣

Haha...I guess. This issue is pretty simple, so my guess is he's accurate and truthful.

[XC3LLR8]

Originally Posted by Dinosoar

Haha...I guess. This issue is pretty simple, so my guess is he's accurate and truthful.

My Genius told me the ZTK package has a transmission cooler, but not an extra oil cooler, and has the same size calipers as the non-ZTK. So there’s that.

[Mike_H_]

Originally Posted by XC3LLR8

My Genius told me the ZTK package has a transmission cooler, but not an extra oil cooler, and has the same size calipers as the non-ZTK. So there’s that.

I have ZTK too, once oil hits 210, it doesn't seem to budge, BMW has the cooling sorted out.

There are also people here who insist the car doesn't have active lower grille shutters.

[XC3LLR8]

Originally Posted by Mike_H_

I have ZTK too, once oil hits 210, it doesn't seem to budge, BMW has the cooling sorted out.

There are also people here who insist the car doesn't have active lower grille shutters.

Attachment 3150868

Attachment 3150869

I sure hope it budges above 210, since that’s not hot enough to evaporate condensation.

But you’re right, it manages heat extremely well.

[apez]

Originally Posted by Dinosoar

I'm sure I look weird to my neighbors vacuuming and wiping down my engine.

Can't be worse then what they think when I am out hand washing with snow on the ground!

Car people will get you, and to hell with the rest. They have their own weird things.

[XC3LLR8]

Originally Posted by apez

Can't be worse then what they think when I am out hand washing with snow on the ground!

Car people will get you, and to hell with the rest. They have their own weird things.

I have an automatic car wash membership.

[danallxt]

I have ZTK too, once oil hits 210, it doesn't seem to budge, BMW has the cooling sorted out

.

Are you sure you are not looking at water temp?
The oil temp gauge on my M240 is way to crude to determine any exact measurement, it has a 45 degree temp rang between bar scale indicators, so it's a crude guess as to what it actually is.

Oil temp will vary a lot depending upon how its driven and the conditions its driven in. My previous ride's H20 temp would stay rock steady at 210 degrees (after a very quick 1-2 mile warmup) no matter what. On the other hand the oil temp would vary a lot. It had a digital oil temp readout to the nearest 1 degree. My oil temps would vary according to ambient air temp, urban vs rural driving, and how hard i was driving and how much turbo demand i was using.