Mosselman Oil Thermostat DIY for the BMW N55/N54 engine!

[@josefelipeism]

One of the most thorough and informative videos on auto repair. Well done.

[@BMWDIYGuy]

Thanks 👍

[@chori12341]

I red that is for keeping the temperature 20 Celsius below OEM. But with the MHD flash there is an óption to do that ( it was realesed 4 months ago)

[@BMWDIYGuy]

Not familiar with that option in MHD, but it's good to have options

[@NoSmileification]

@@BMWDIYGuy He is mistaken, that's the coolant temperature he'stalking about. MHD and/or the ECU has no control over oil temps. I'm hoping to install my MSL thermostat this summer too.

[@3diablo3]

@@BMWDIYGuy MHD control only water pump not oil temp. Lowering the water temperature also lowers that of the oil, but it is not enough.

[@Marky_Markster]

MHD Sport or Track cooling overruns the water pump, which yes does decrease oil temp but it will wear out your waterpump sooner, already a fragile unit. A lower temperature spring, like in this Mosselman, will allow oil to run through to the oil cooler at a lower temperature. Main benefit is lower running temperature at daily driving conditions. No difference on the track though, where extended hard running the thermostat would have already been open anyway and the limiting factor then becomes the size of your oil cooler and the quality of your radiator.

[@mkwlls]

Love your videos Stefan. You give the best views and most detail of anybody I've seen on KZbin. Keep em coming.

[@BMWDIYGuy]

Happy to help!

[@whiterabbit3464]

AWESOME DIY VIDEO, thank you!

[@BMWDIYGuy]

Glad you liked it!

[@chipsth1]

What temps are you seeing on average after this install? Before?

[@BMWDIYGuy]

On average I saw about 20 degree drop in my N55 and about 15 in my S55.

[@pilarbojorquez1080]

Great video.

[@BMWDIYGuy]

Glad you enjoyed it

[@vincentsulaiman2011]

Can I ask what the thermostat actually does? Why would you change the stock one? I might be naive here, but how does it “cool” the oil more?

[@BMWDIYGuy]

It is a more efficient thermostat and opens ealier in the temp cycle. Brings average Temps down by about 10 degrees

[@3diablo3]

Can anyone confirm that the oil cooler radiator stays cold before reaching 85 degrees? My fear is that below 85 degrees it is always a bit open.

[@JrzyG80]

Great video Applies to the S55 engine as well if anyone wonders

[@BMWDIYGuy]

Definitely check in with Mosselman as they have fantastic options for S55s as well.

[@JrzyG80]

BMW DIY Guy I did I just did the install myself. Not much different from what you did

[@3rkowtf669]

Great video, just curious what would be the difference between this thermostat and oil thermostat valve normally sold by Burger motorsports which is even simpler to install, obviously they aim for the same goal but, any main pros or cons between them? Thank you.

[@BMWDIYGuy]

Great question and one I can't effectively answer. I haven't installed the BMS upgrade so sadly can't compare the function. The only quick obvious comparison I can make would be the dramatic appearance of the MSL unit, rather than just an internal upgrade on the oem.

[@3rkowtf669]

@@BMWDIYGuy Thank you much, I’ll do a little bit more research on my own before I pull the trigger on the thermostat itself. Thank you

[@jirik1721]

Hi, can you tell me, what's the REAL oil-teperature difference before and after istalation? Thanks

[@BMWDIYGuy]

I dropped about 20 degrees on average with my N55, and about 15 with my S55

[@BenPhamily]

I have a f32 and often do self maintenant. How do I find out the torque specification for each bold. Thank you for your help.

[@BMWDIYGuy]

There is a website called NEWTIS that might have the info you are looking for, as it has the official BMW guides for various parts including torque values.

[@Trusty335is]

Great video! Would you recommend their oil cooler as well? Looking at purchasing their single cooler kit with thermometer upgrade. What are optimal oil temps I should look to achieve? Summers are over 100 degrees here and I like to go on canyon runs. I don’t track my car but it is FBO with inlets. I have a 2013 335is coupe DCT. Thank you!

[@BMWDIYGuy]

With temp that high, I would definitely consider the upgraded oil cooler as well.

[@Trusty335is]

@@BMWDIYGuy Great! Thank you for the big help. Will order now :)

[@daveg7464]

no need to prime your engine first?

[@BMWDIYGuy]

Not that I have heard of..

[@aaronbrown4366]

Great video. Would you recommend this on a stock, not hard driven N55? I feel with something like this, I might not constantly get up to operating temps based on driving habits. But, I live in LA, and ambient temperature can play a factor. During normal daily driving I hit 250f, sometimes a tick or so before 250 if it’s a cooler day and I’m on the freeway. I run motul 5w40 if that’ll figure into your recommendation. Thanks!

[@BMWDIYGuy]

Yes, especially in warm environments

[@aaronbrown4366]

@@BMWDIYGuy Thanks for the quick response. One more question if you don’t mind. Would you recommend me getting the crank seal guard done immediately? I know oil and coolant leaks can be random, but my car is currently in good health/no leaks and has 30k miles (2014 435i M Sport) or as long as I keep an eye out, I should be fine and have it done once I have the serpentine belt done at around 40-50k miles? Unfortunately I’m not mechanically inclined to do these types of jobs myself, so I’m trying to weigh out the risk as I will have to pay to get it done. Thanks so much!

[@BMWDIYGuy]

@@aaronbrown4366 I would do it the same time as the belts.. it's a good idea in general.

[@aaronbrown4366]

@@BMWDIYGuy Thanks again and will do.

[@sebastienmarquet8686]

Thanks for the video! How did you manage to clean all the oil on the engine and belt? Brake cleaner and high pressure water clean?

[@BMWDIYGuy]

Stuffed rags and paper towels under the housing before I took it off.

[@sebastienmarquet8686]

@@BMWDIYGuy yes i saw that but i had a leak before so all my front engine including the belt are covered with oil, so i was looking for the best way to clean it! Thanks for your reply!

[@goolamuns.a.hussein6993]

@@sebastienmarquet8686 spray carburator cleaner then high pressure water clean.

[@hypertrophy07]

Great video, you just earned yourself a new subscriber! Did you make a follow-up video regarding this mod?

[@BMWDIYGuy]

I havent yet no..

[@hypertrophy07]

@@BMWDIYGuy What are you thoughts on this kit after having it installed for a while?

[@BMWDIYGuy]

@@hypertrophy07 love it!

[@hypertrophy07]

@@BMWDIYGuy What were your temperatures before and after?

[@alextovar2586]

Do I have to prime the engine before starting the car ?

[@BMWDIYGuy]

No

[@edgardoarroyo7418]

Did you prime the oil system before runing the engine?

[@BMWDIYGuy]

No, not needed in general.

[@badboygto]

hi im very intrested in buying one of these for my 335i im in the uk mine is a m sport with a oil cooler i reach 118c not farahnite (just under half way on the dial )in hot weather ...my concern is our winter usualy doesnt go worse than between 7c to -5 c tops ...will my car still reach safe oil temps dont want it to be undercooled any advise be greatly apreciated

[@BMWDIYGuy]

I would have zero concerns on being too cold, but you could also confirm with Mosselman before doing the installation. I am willing to bet you wouldnt have issues.

[@badboygto]

@@BMWDIYGuy thank you very much for the quick reply yes i will send them a message i know its perfect for summer aslong as it reaches 95c in winter wil be happy enough to burn the crap out .looks a decent bit of kit and a lot better option than the bypass valve. been nothing but keeping up maintanance since i baught it time for some goodys for it now :)

[@npharkes]

How does this increase engine life?

[@BMWDIYGuy]

Helps to reduce oil temps and the thermostat opens earlier than OEM too. Definitely check the product link for details

[@aconfusedazn]

Isn’t this a thermostat and not a thermometer?

[@BMWDIYGuy]

Correct.. I kept saying thermometer in the video which I didnt realize until later.

[@az21240]

I have been thinking so much of buying one of these for months now... But is it a good idea of changing the engine combustion/running temperature, there was the original thinking from the factory? 🤷‍♂️🤔 great video btw!

[@BMWDIYGuy]

I believe helping to keep oil temp down especially if you are tuned or running the motor harder is a great idea

[@az21240]

@@BMWDIYGuy yeah I think you’re right... I just changed mine today, because it took long time for the engine to heat up, above 50 degrees. After the change, it heat up quick again.... I have one question... When I loosen the bottom bolt, a bit of, what looked like coolant was coming out? 😳 It felt like it was under pressure. My oil temp was about 67 degrees hot, when I took it off.... My thirst thought was DAMN! But the coolant looked clean, with no oil in it? And the rest of the oil looked fine?? But does it mean that I have coolant in my oil?? 🥵

[@BMWDIYGuy]

@@az21240 So candidly if so, that is concerning. If you have an oil change coming up, make sure to either check your oil or have your shop check the oil for contaminants.

[@az21240]

@@BMWDIYGuy I have a guy that thinks it’s because the system has been under a little pressure, because of the temperature, and then some coolant has come out, because the water run along the system.

[@az21240]

@@BMWDIYGuy but something I definitely will check up on ASAP!

[@jackhere4594]

can u tell me if there is a large c clip on rt side of that short upper radiator hose comin out from under the housing? there is one on left side i can see, but mine does not have large c clip on the other side

[@BMWDIYGuy]

Not that I remember but another idea is checking realoem.com. Look at the parts diagram for that part and see if it's there.

[@jackhere4594]

@@BMWDIYGuy i didnt see it there, nor do i see it on parts offered for sale on fleabay(allshow one on left side under housing), but one seller told me it was not part of the diagram( he cudda just been talkin), but where else on realoem would i look? i just dont know

[@BMWDIYGuy]

@@jackhere4594 yeah just don't remember one being there..

[@paduganankyle3927]

Hi thanks for replying last question about the avin backup camera, is that normal that the quality of the video at night is like 30% compared to morning time? Its like so different

[@BMWDIYGuy]

I have no issues with the camera I installed in my X5

[@jg_media9]

where'd you get this engine bay cover?

[@BMWDIYGuy]

So I painted mine.. I have a DIY on it, though am NOT a pro painter by any means. It turned out surprisingly great considering my painting skills. There are also several companies that can paint a custom vanity cover for you.

[@jg_media9]

@@BMWDIYGuy definitely looks great for sure! I'll check out your DIY on this then

[@jg_media9]

@@BMWDIYGuy for the mosselman thermostat did you prime the system or no?

[@BMWDIYGuy]

@@jg_media9 nope, no need.

[@jg_media9]

@@BMWDIYGuy cool thanks for letting me know! Diving into this install shortly. Ill see you in a few weeks at the Kies show 👊

[@sonic6642]

I see you replying maybe I’m a little late. I have a e92 without the thermostat to start with. Gonna do the oil cooler and thermostat kit for $1000 USD will I have problems mounting the cooler? I have pdc holes and headlight washers

[@BMWDIYGuy]

I haven't done an e92 but as long as it's compatible, I would expect you to be fine

[@sonic6642]

@@BMWDIYGuy thanks

[@davewallace9048]

What torque wrench are you using?

[@BMWDIYGuy]

I actually have two now, both really good to cover the full range of any torque values I need. I have the Gearwrench 85077, good for 30-340 Nm values. I also have the Gearwrench 85076, good for 10-135 Nm values. Easy to use, batteries last a long time in them, really serve me well. No more stupid click, turn, dial whatever wrenches.

[@fthirty3]

Would you recommend doing this during an oil change to limit the amount of oil that comes out while replacing the thermostat?

[@BMWDIYGuy]

I lost so little, I am not concerned. I have an oil change later this week as I need it, but not out of concerns on levels.

[@fthirty3]

@@BMWDIYGuy I meant more so that there was less to clean up. I try to keep my engine super clean too :)

[@BMWDIYGuy]

@@fthirty3 really dont think so as you just get the oil off the top of the pipes, and a little sitting in the housing. Great question though.

[@recklessjim117]

So I have these problem that I have to change in my bmw 335i n54 but im not sure if I have to change oil cooler thermostat housing or the lower thermostat + water pump? Help!

[@BMWDIYGuy]

Sorry, not sure I understand your question?

[@recklessjim117]

BMW DIY Guy my check engine light is on and my car goes into limp mode but I’m not sure what I have to change, bc some temp pops up in my speedometer

[@greaterbw]

I’m in love with these but damn $300 for one of these 🤦‍♂️

[@BMWDIYGuy]

I think it is worth it, but that is just me. 8)

[@towncar968]

Where you get the gasket from

[@BMWDIYGuy]

Ordered from them directly with the thermostat

[@jackhere4594]

my mosselman gets CRAZY hot. after like 4 miles of driving. i cant touch it for like an hour. urs get that hot? they say it has a real thermostat in it.kies motorsports say thats normal. hows a small thermo like that gonna hold up to this type o heat?

[@BMWDIYGuy]

Perfectly normal.. oil temps are often 200 degrees plus so it being that hot is normal

[@jackhere4594]

@@BMWDIYGuy rt,but has mosselman told anyone of a replacement thermo when this one goes out?

[@BMWDIYGuy]

@@jackhere4594 I haven't heard of one failing

[@MosselmanTV]

It's normal that the oil thermostat housing gets hot. The thermostat inside is fine, don't worry about that ;)

[@jackhere4594]

@@MosselmanTV i just got oil pressure low warning light on idrive and odometer. after driving for about 2 hours, first time i drove that long since the mosselman has been installed. is this normal? no leaks anywhere and new oil pressure sensor installed when mosselman was installed.

[@josefelipeism]

Might you know where the oil temp sensor is?

[@BMWDIYGuy]

Its under the throttle valve assembly, plugged into the block. Not an easy change.

[@155JMM]

Many questions but little response from this BMW DIY Guy... Not so good for the reputation.. My comment is: What is the reason for this Mosselman oil thermostat update? Of course it will be better but why would this upgrade be necessary? Is the oem thermostat that bad? This is a big miss in your video, "The reason why"...well

[@BMWDIYGuy]

Here is the why direction from Mosselman, and the experience in my S55 and N55 have been similar improvements. MSL OIL THERMOSTAT The next level of temperature control 20°C Lower Than Stock Operating temperature 20°C lower than stock. Real Thermostat Equipped with a real thermostat, not an always open solution. (for use in hot and cold climates) Rock Solid Housing Made out of a solid block of high-grade aluminum.

[@DigitalDissident]

+1