Engine and Engine Bay Heat Management?

[Ralph III]

Hello Everyone,
I asked a similar question in a specific thread a while back but here it goes again.

Has anyone taken any steps to lower their engine and engine bay temperatures? It's well known that the N63 engine generates a lot of heat and I'm trying to mitigate that with our 2018 650i which has the N63tu.

Anyhow, I will be getting a lower t-stat installed at some point, probably 100c. I know that's not a lot but it should be beneficial over the life of our 650i given it's a daily driver. I'd prefer to go with a 90c or 95c t-stat but I've read where people started getting fault codes with those low t-stats?

Beyond that, I'm contemplating installing a few 3-4in electric fans to introduce cool air into the engine compartment. These will be used to cool the engine compartment down after having driven it. I know the cars fan runs for a few minutes after shutting the vehicle down but it's effect is minimal. Can that be programmed to run longer? The problem is, the compartment is so cramped there is no easy placement for the fans no matter how small. Installing them on the outside of the radiator would seem the best location? Otherwise, it might be possible to install those over the fender wells to draw in fresh air or to disperse hot air (if reversed). It's also possible to blow air directly into the cavity of the hood itself which would then blow directly onto the top of the motor via existing holes. I'm not sure how effective blowing air on the top of the motor would be though?

Your input is appreciated,
Ralph

[scubachris]

hi.
i have friends who race cars and the general feeling is that to cool down under the bonnet/hood it is more efficient to get the hot air out rather than trying to get cool air in,,usually using scoops or louvres ect opening towards the rear of the car.so air flow when driving drags the hot air out..also helps with stationary heat soak..possibly ducting from under the engine bash plate too..
maybe heat wrap or ceramic coating on the exhaust downpipe/headers helps too.

[Walt White Coupe]

I think removing the engine cover reduces the trapped heat at the top of the engine and increases the ambient air flow above the engine.

[Oris4]

I’ve been on the fence about removing downpipe heat shield, I have catless dp wrapped in dei titanium wrap and spray with their silicone spray. I’ve heard it helps to keep it on but then I’ve heard it traps heat, I’ve also heard removing it can damage hood/paint. Any input?

I also run the oil cooler as I primarily drive my car in warmer months and that has helped.

[Ralph III]

Thanks for the input and let me respond to a few.

1) I am also contemplating putting a heat wrap on the turbos and forgot to mention that. There just seems to be so many varying opinions on that though. Some say it will damage the turbos and even hinder the engine cooling down because the heat wraps are then trapping the heat inside?

2) It would seem removing the engine cover would be a good thing but I did read where someone, apparently quite knowledgeable, stated not to. He provided infrared images of the engine bay and stated the engine cover is used to direct air flow and you'd be doing more harm than good by removing it.


So, nobody has installed any cooling fans and what about turbo blankets? I won't be wrapping or coating the down pipes.

Ralph

[JBF650]

Originally Posted by Ralph III

Thanks for the input and let me respond to a few.

1) I am also contemplating putting a heat wrap on the turbos and forgot to mention that. There just seems to be so many varying opinions on that though. Some say it will damage the turbos and even hinder the engine cooling down because the heat wraps are then trapping the heat inside?

2) It would seem removing the engine cover would be a good thing but I did read where someone, apparently quite knowledgeable, stated not to. He provided infrared images of the engine bay and stated the engine cover is used to direct air flow and you'd be doing more harm than good by removing it.


So, nobody has installed any cooling fans and what about turbo blankets? I won't be wrapping or coating the down pipes.

Ralph

Short of you doing track days and racing I've no idea what the actual point of installing auxiliary fans and cooling items under the bonnet will do for you. BMW have engineered the car to operate perfectly in most normal climates with the cooling system it has on it.
With respect to WWC, I wouldn't remove the engine shroud and top cover as this provides a barrier to heat soak to the bonnet. Heatsoak 'may cause' damage over time to the finish of the bonnet.... i stress may ....
I live in Sydney Australia and while i don't drive my 650 daily or even weekly i do drive it regardless of the weather conditions outside. So that can be anything from fry an egg hot or rainy cold and miserable.... I've never ever had any issue with the car in hot weather re-starting or performing as it should.
I honestly have no idea why you are intent on installing all this extra cooling palaver under bonnet if you are using the car as intended.
True it gets very hot under there but probably no more no less than most other large force fed induction motors.
If you are that worried the easiest and most effective way to dissipate the heat after you go for a drive is park it with the bonnet open for 10 minutes... job done

[Walt White Coupe]

JBF,

With respect to WWC, I wouldn't remove the engine shroud and top cover as this provides a barrier to heat soak to the bonnet. Heatsoak 'may cause' damage over time to the finish of the bonnet.... i stress may ....

I've been running my 650 with the cover off for around 5 years now. You have to realize that there is a rubberized heat shield on the underside of the hood (bonnet) that insulates the hood from engine heat. And of course, the cooling fans run at engine shutdown on hot days so there's that.

I decided to keep the cover off when I was pulling the cover for an inspection under it and felt how hot the cover was. It has to trap heat. So far so good with mine.

[JBF650]

Originally Posted by Walt White Coupe

JBF,

With respect to WWC, I wouldn't remove the engine shroud and top cover as this provides a barrier to heat soak to the bonnet. Heatsoak 'may cause' damage over time to the finish of the bonnet.... i stress may ....

I've been running my 650 with the cover off for around 5 years now. You have to realize that there is a rubberized heat shield on the underside of the hood (bonnet) that insulates the hood from engine heat. And of course, the cooling fans run at engine shutdown on hot days so there's that.

I decided to keep the cover off when I was pulling the cover for an inspection under it and felt how hot the cover was. It has to trap heat. So far so good with mine.

yep all true WWC, again no disrespect to you or your suggestion. your car you do as you wish mate, all good

My comment is mainly addressed to Ralph and to allay his concern with under bonnet temps.
As you say WWC, the cooling fans run for a a short time after a drive if its very hot so all good.
Improbable eventualities or suggesting convoluted solutions for issues that just aren't there doesn't seem logical to me.

[Ralph III]

QUOTE by JBF650...."yep all true WWC, again no disrespect to you or your suggestion. your car you do as you wish mate, all good

My comment is mainly addressed to Ralph and to allay his concern with under bonnet temps.
As you say WWC, the cooling fans run for a a short time after a drive if its very hot so all good.
Improbable eventualities or suggesting convoluted solutions for issues that just aren't there doesn't seem logical to me.

Hello JBF650,
I really don't get your responses with due respect. The N63 has a notorious history of engine issues caused by the excessive heat it generates due to the hot v design. That's in part why it went through all of the modifications, lawsuits, and then customer care packages being offered, etc. The upgraded N63TU engine was included in some of these lawsuits, btw, as they also suffered from some of the same issues as the original version. All due to the excessive heat the engine generates. You're simply wildly inaccurate to say that BMW "perfectly engineered the car to operate perfectly in most normal climates...". If that were the case, they'd have a warranty of 10yrs or 100k miles. No, BMW was required to engineer the car to meet certain government regulations such that was not beneficial to the car itself.

So, why would you take issue with my taking a few pro active steps or making an inquiry, just as many others have taken, in an attempt to mitigate such? Otherwise, we absolutely love our 650i and I'd like to be able to keep it for a while. You just don't hear of owners getting a lot of high mileage out of these though. Whereas our 530xi has over 260k miles on it and still running strong.

Our 650i doesn't really have any issues at the moment but there are two things I've recently noticed. It is starting to lose a little oil, so I'll be keeping an eye on that. In addition, the rubber seal/weather strip under the hood (bonnet) is crumbling and there is no doubt the engine compartment heat is causing this degradation.

Yes, I could and do actually open the hood after parking the vehicle on occasion. This results in the engine compartment cooling down nicely. That however is not a legitimate or long term solution. A long term solution would be to have the fan or other fans running longer to expel the heat after parking it. A long term solution would be to have the vehicle run at a cooler temp (lower t-stat) which would result in less heat being generated.

If you have something legitimate to add to the conversation then I welcome that. If not, please leave it to others to share their experiences.

Thanks,
Ralph

[JBF650]

Originally Posted by Ralph III

Hello JBF650,
I really don't get your responses with due respect. The N63 has a notorious history of engine issues caused by the excessive heat it generates due to the hot v design. That's in part why it went through all of the modifications, lawsuits, and then customer care packages being offered, etc. The upgraded N63TU engine was included in some of these lawsuits, btw, as they also suffered from some of the same issues as the original version. All due to the excessive heat the engine generates. You're simply wildly inaccurate to say that BMW "perfectly engineered the car to operate perfectly in most normal climates...". If that were the case, they'd have a warranty of 10yrs or 100k miles. No, BMW was required to engineer the car to meet certain government regulations such that was not beneficial to the car itself.

So, why would you take issue with my taking a few pro active steps or making an inquiry, just as many others have taken, in an attempt to mitigate such? Otherwise, we absolutely love our 650i and I'd like to be able to keep it for a while. You just don't hear of owners getting a lot of high mileage out of these though. Whereas our 530xi has over 260k miles on it and still running strong.

Our 650i doesn't really have any issues at the moment but there are two things I've recently noticed. It is starting to lose a little oil, so I'll be keeping an eye on that. In addition, the rubber seal/weather strip under the hood (bonnet) is crumbling and there is no doubt the engine compartment heat is causing this degradation.

Yes, I could and do actually open the hood after parking the vehicle on occasion. This results in the engine compartment cooling down nicely. That however is not a legitimate or long term solution. A long term solution would be to have the fan or other fans running longer to expel the heat after parking it. A long term solution would be to have the vehicle run at a cooler temp (lower t-stat) which would result in less heat being generated.

If you have something legitimate to add to the conversation then I welcome that. If not, please leave it to others to share their experiences.

Thanks,
Ralph

Its a public forum and you asked for comments and advice from owners. I have added legitimate comments Ralph, if they aren't what you want to hear then that's a matter for you. Ill contribute nothing further on this thread, its falling on deaf ears, its your car at the end of the day, you do with it what you like.

Wish you luck with it all.

[Ralph III]

Originally Posted by JBF650

Its a public forum and you asked for comments and advice from owners. I have added legitimate comments Ralph, if they aren't what you want to hear then that's a matter for you. Ill contribute nothing further on this thread, its falling on deaf ears, its your car at the end of the day, you do with it what you like.

Wish you luck with it all.

JBF650,
I asked for specific responses from 650i owners who had taken steps to mitigate the excessive heat generated by their vehicle.

"Has anyone taken any steps to lower their engine and engine bay temperatures? It's well known that the N63 engine generates a lot of heat and I'm trying to mitigate that...."

I didn't ask for input from those who don't feel such is necessary because I didn't won't it to devolve into a debate of the subject. I've done my homework and I think taking some minor steps would be very beneficial. So, the question is what steps have others on this forum taken.

Otherwise, I'd be very interested to hear from anyone, who can say they've put over 150-200k miles on their N63 engine with no issues.

Take care,
Ralph

[KMP259]

Interesting thread…. Has anyone thought about raising the rear of the hood to evacuate hot air under the hood…????

[Ralph III]

Originally Posted by KMP259

Interesting thread…. Has anyone thought about raising the rear of the hood to evacuate hot air under the hood…????

No, but I have seen people remove the engine bay weather gasket to allow the heat to escape. You'd think removing that and the engine cover, as WWC noted, would help in regards to expelling heat from the 650i engine compartment. Otherwise, they seem to trap heat.

After posting the above I decided to check this out as my wife just arrived home from work. I took the engine cover off and got measurements of 350 degree up to 450 degree under the hood. And yes, the engine bay gasket is responsible for holding in most of the heat. In fact, it's so effective that you can't feel any engine bay heat where the windshield wipers are.

I then removed the gasket and shut the hood. With that, the engine bay heat was then able to escape from under the hood, at the windshield wipers. So, the question is whether or not the gasket can be removed or vents installed at that area to allow the heat to escape. Or does the gasket serve to force the air to flow down the firewall and over the manifold and exit under the vehicle while driving? In which case, removing the gasket could possibly disrupt that and cause more heat to be felt from the manifold. I'm going to make an inquiry with BMW directly in regards because a modification would be quite easy if viable.

God Bless,
Ralph