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

[Cryptikz]

Originally Posted by Ralph III

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

Hey Ralph,

Any updates on your cool n63tu journey?? I recently got a 2016 650i xDrive Gran Coupé and I'm trying to mitigate as much heat as possible. Could cold air intakes help with this? It seems like removing the big air boxes would allow the engine bay to breathe more, but maybe I'm wrong.

Curious to hear what you've done.


Thanks!
Spencer

[Ralph III]

Originally Posted by Cryptikz

Hey Ralph,

Any updates on your cool n63tu journey?? I recently got a 2016 650i xDrive Gran Coupé and I'm trying to mitigate as much heat as possible. Could cold air intakes help with this? It seems like removing the big air boxes would allow the engine bay to breathe more, but maybe I'm wrong.

Curious to hear what you've done.


Thanks!
Spencer

Hey Spencer. No, I haven't been able to do anything significant as yet, for a variety of reasons. The minimal things that I have done are as follows.

1. I removed the engine cover and then installed a thermal heat shield to the underside of the hood. There is no doubt this is beneficial because the cover essentially traps the hot air around the engine. I'll put the engine cover back on during the winter months, as it will be somewhat beneficial during that time. Whereas I feel it's detrimental during the summer months.

2. I did a partial radiator flush and then added new coolant. I've also added Water Wetter.

3. I often pop the hood upon parking the car and after a drive. This is very beneficial because it allows the engine compartment heat to escape and thus the engine cools down much faster.

4. I will be adding a bottle of STP AT 205 soon and prior to my next oil change.

5. I'm being careful to change the oil at every 5,000 mile interval.


--------------------------------------------------------------------------------------

This is what I will be doing and also that I am considering.


1. I just received my 90 degree thermostat from ECS Tuning and I'll be installing it within the next month. There is no doubt, as with regular oil changes, that this will be the most beneficial for the vehicle.

2. Like you, I believe installing a fresh air system and removing the current air boxes would be good and it's something I will be doing at some point. In thinking outside the box though, I'm considering whether the air boxes could be converted to introduce cool air into the the engine compartment via exhaust fans installed within them. There are other ways to do this though, so it's a matter of what is most practical or beneficial. If done properly though, it would allow the car to retain it's stock appearance for the most part and thus professional look. Whereas, it would not retain the same professional aesthetics by removing the air boxes entirely.

God Bless,
Ralph

[Thecastle]

This topic has appeared in other forums so you may want to search there. I'l share some of the info I've seen/contributed. I have owned multiple V8 BMWs and spent a lot of time cooling down my S63. Cooling is part of the problem, you climate, and the material choices BMW made are par of the issue.

So some general recommendations.
1) 90C thermostat, simple swap will cool your cars internal temps and help protect valve stem seals and plastic internal components/cooling components. Also a low temp oil t-stat, not a good idea if you live in a cold climate. Downside reduced fuel economy.
2) I would not remove the weather stripping if the vehicle is operated or parked outside in the rain. The purpose is to keep water out of the engine bay. Having a broken engine partition, windshield tray and weather stripping is known to over time cause corrosion and problems with injectors and sensors in the engine. Ask E70 owners about the problems with water leaks underhood. If this isn't a concern it makes a difference.
3) Turbo blanket over the turbos will significantly lower under hood temps. I've measured it. It will also increase the spool speed.
4) Maybe switch to 1000W cooling fan, may improve cooling.
5) The engine cover is there for sound reduction. It doesn't make a ton of difference in keeping the engine cooler, I've used a heat gun with it on and off. Its not a major difference. Also the turbos are covered with heat shields to really reduce the radiant heat.
6) Wrapping exhaust pipes and lines will help them last longer, or converting to silicon
7) I no longer recommend AT 205 as a preventative, project farm did a review and showed that it significantly increases engine wear/damage for leak stopping. It does work, and it works well if you have bad valve stem seals, but its not a fix, its a trade in motor honey.

Here is some data form X5M owners. https://www.xbimmers.com/forums/show....php?t=1836146

Yes not the same engine/layout but still same goals.

[Ralph III]

Hey TheCastle. Thanks for the input! You're spot on with the turbo blankets and 90 degree t-stat. There are other steps that can be taken to mitigate engine and engine bay temperatures also; but those two items alone would be significant. I'd like to address a few things though.

quote by TheCastle...."Also a low temp oil t-stat, not a good idea if you live in a cold climate. Downside reduced fuel economy."

Are you referring to the Sport Oil Cooler Valve? Because after quite a bit of research and thought, I would not recommend it under any circumstance. The vehicle is designed to warm up the oil as fast as possible which is best, as it minimizes wear and tear. Then, once it reaches the oils most effective operating temperatures, it will maintain it. This makes the Sport Oil Cooler Valve both unnecessary but also detrimental. It is completely unnecessary because the car will never allow the oil to reach a detrimental operating range anyhow. It is damaging because it will thwart the cars ability to warm up the oil to proper temperatures and/or it will delay it. This will lead to increased wear and tear on internal components which could prove significant depending on driver habits, such as constant short commutes.

quote by TheCastle...."I would not remove the weather stripping if the vehicle is operated or parked outside in the rain."

I've read numerous pros and cons on this also. It's not so much of a concern of water getting into the engine compartment, as the water will be diverted via the metal lip that the stripping attaches to. The problem is, you'd possibly be sucking in exhaust fumes and heat from the engine bay through the AC fresh air intake and that would be dangerous.

quote by TheCastle....."Wrapping exhaust pipes....".

I'd love to be able to do this and there is no doubt it would be very beneficial. There is a lot of concern with exhaust wraps trapping moisture and then rusting out the pipes though. Do you have experience with this first hand on your BMW's? Otherwise, I chose to go with a heat dissipation paint made by ZyBar. It seems gimmicky but I contacted numerous reviewers directly who were not compensated for their review and who swear by it.

quote by TheCastle...."I no longer recommend AT 205 as a preventative, project farm did a review and showed that it significantly increases engine wear/damage....".

I watched the same review during my research. It's an excellent review but the wear test portion is misleading and it DOES NOT show that it "significantly increases engine wear/damage" as you state. That is a misinterpretation and wildly inaccurate.

His wear test is simply for comparative purposes between the products for your consideration. Otherwise, its completely useless for real world considerations because it tests the products at what would be considered an absurdly abusive level. Despite such, AT 205 is actually one of the best performers in this category when compared to the oil alone "control". So, his test here should be taken with a grain of salt because.....

1) He tested 1.4 ounces of liquid at a 50/50 ratio of synthetic oil and the various products. That would be like running 4.5 quarts of AT205 and 4.5 quarts of synthetic oil in my BMW 650i engine. When in reality, I'm running 9 quarts of synthetic oil to only 12 ounces of AT205.

For his test to have been accurate, he would have only used about 30 droplets of AT205 to 1.5 ounces of synthetic oil. The problem is, it would have most likely never shown any wear. So, he tested the products at an extreme and abusive degree but again just for comparison purposes. I wouldn't recommend running AT205 in a vehicle all of the time as a matter of practice, but that would not be necessary anyhow.

2) My recommendation is to add AT 205 just before an oil change. Then run it for at least 5 hours or so in the engine and prior to changing the oil. Then perform the oil change without adding AT 205 back into it. I plan on using it prior to every two or three oil changes and I have no reservations or concerns with such.

Given all of the above, it's highly unlikely your engine would ever experience any additional wear and tear. Or at least anything measurable over its' lifetime. On the other hand, if you watch his review, you will see that AT205 does a phenomenal job of restoring seals and gaskets which it is in fact designed to do. So, briefly add it to your engine oil and then remove it. There are just tons of real world testimonials of it's effectiveness and safe usage.

God Bless,
Ralph