[locum]

Anyone running ER Oil Cooler together with Mosselman Oil Thermostat on N55 engine?

https://www.mosselmanturbo.com/en/msl-thermostat-n55
http://www.evolutionracewerks.com/node/299

I already have Mosselman installed and my engine temp did go down to about 105C / 220F which is great (it was always 120C prior to the install).

My plan is to do MHD 2+ and install Pure 1 turbo.

Do you know if I also need to install ER oil cooler? Or the Mosselman is already enough?

Obviously, do not want any engine damage by lowering the temp too much.

Thank you!

[DJSF3014]

When I had the mosselman on my big boost turbo n55 temps would never go above 205 or so which is lower than you'd ideally like. This was in North Carolina so no extreme temps I also didn't drive the car hard either but had sport cooling selected in mhd custom tune file and worked great I would say keep it with that then if you see the need can add the other.

[n55david]

unless you're doing auto x and road courses etc you don't want the coolers etc. only exceptions are areas where it's blistering hot all the time.

[thejeremyman9]

The thermostat and the oil cooler address two different things.

The thermostat lowers the temperature at which oil begins to be circulated to the OEM oil cooler. It does not increase cooling capacity. This can "indirectly" prevent oil overheating by starting the oil at a lower temp in the same way a lower coolant temp target would prevent engine overheating, but its just a delay really, not prevention.

The oil cooler upgrade increases the cooling capacity of the system but does not address the oil thermostat temp, so if you installing this on a stock car it would have no effect until you were exceeding cooling capacity of the OEM cooler.

OP mentions "engine temp" but this is a misnomer because the engine oil and coolant operate at different temps, sometimes 40+F different than one another.

The bottom line is that the engine was designed by OEM to operate at the OEM temp. The only reason to change either or both of those things is if you are exceeding the capabilities of the respective components.

There's not necessarily a problem with lower oil temps, but you want to be over 212F to remove moisture and you will probably lose some fuel economy.

[1bad14-F30]

212* min. to burn off condensation in the crankcase as mentioned above. This is why short trips destroy oil and shorten change intervals. Also today's synthetic oils are designed to run between 230-250*. I was looking to do the oil thermostat mod and maybe get the additional cooler as well. After many hours of research and refreshing my memory of when I was crewing for some local vintage race guys, remembered the oil temps were always 240-250*. Never any issues. I drive my car hard and have never gotten over 240*.

[visionaut]

I’ve been running the Mosselman Oil Thermostat for more than two years now. It keeps my steady-state high temp lower by about 15-20 degrees, from my prior 250 avg to now 230-235 avg. It has never run steady below 220, so no below boiling point fears. I’m an engineer and know about the higher temps for oils for efficiency nowadays, and the details regarding BMW’s N55 cooling systems design. But I like the slightly cooler running engine for the better performance, with no ill effects. I’d always rather be at 235 than at 255 in similar circumstances. I don’t care about a little extra gas mileage loss. And at altitude here the engine is already running hotter than it would at sea level. So the oil thermostat manages the outboard oil cooler better than stock to drop/keep my steady-state temp cooler. I’m happy.

Re: OPs question - Mosselman offers a T-stat/Cooler bundle (with the CSF cooler), so I don’t see any reason why it couldn’t work with the ER cooler as well. I’m friends with the shop foreman at my local BMW dealer, and he was so impressed after driving my car with the Oil T-stat, that he bought one for his team’s racecar to pair with the CSF oil cooler they already had. They’ve liked the pair a lot for racing. He didn’t think I’d see any value in upgrading to the CSF cooler for a street car like mine.

[MTWO]

If you street drive your car mostly I would suggest against the thermostat mod, no point really plus it just takes longer to come up to full temp in winters. Oil cooler is not bad but unless you track your car hard, again, I don’t see much point in it

[thejeremyman9]

Originally Posted by MTWO

If you street drive your car mostly I would suggest against the thermostat mod, no point really plus it just takes longer to come up to full temp in winters. Oil cooler is not bad but unless you track your car hard, again, I don’t see much point in it

It won't take any longer for the oil to get up to the thermostat temperature, because the thermostat will be closed until that time... so from cold start to the time the thermostat opens will be exactly the same, it's just that one open at a lower temp than the other. So from 0-85C oil temp, warmup time will be exactly the same.

[harkes]

Only positive I see running lower oil temp without increased cooling capacity is to extend the life of the plastic components in the engine - especially the chain guide.

S62 running at lower temps has no known issues with brittle chain guides as opposed to N62.

[locum]

Thank you everyone for your thoughtful responses.
I am moving this vehicle to Phoenix soon where I will be tracking it, so decided to get the ER oil cooler as well.
I now understand that while the oil thermostat helps maintain the min low temp without providing any higher temp protection, the oil cooler will help keep the oil from overheating on the high end. It's like buying a put and selling a covered call, if you pardon the finance analogy.

[thejeremyman9]

Originally Posted by locum

Thank you everyone for your thoughtful responses.
I am moving this vehicle to Phoenix soon where I will be tracking it, so decided to get the ER oil cooler as well.
I now understand that while the oil thermostat helps maintain the min low temp without providing any higher temp protection, the oil cooler will help keep the oil from overheating on the high end. It's like buying a put and selling a covered call, if you pardon the finance analogy.

Probably makes sense to get both in your situation. You probably could have tried the t-stat only and testing oem OC to see if it was enough, but if you are going to track it, why not.

[MTWO]

Originally Posted by thejeremyman9

It won't take any longer for the oil to get up to the thermostat temperature, because the thermostat will be closed until that time... so from cold start to the time the thermostat opens will be exactly the same, it's just that one open at a lower temp than the other. So from 0-85C oil temp, warmup time will be exactly the same.

85c is not the full operating oil temp for this car, thus what I said, is still valid.

[visionaut]

FWIW, the MSL Oil T-stat doesn’t affect my car coming up to temp, summer or winter. It gets to 220-230 almost as fast as before, it just doesn’t go over that now.

The factory oil T-stat opens at a higher temp, but it’s binary, so it’s either fully closed or fully open. When it opens, you get full flow from then on to the cooler.

The MSL is a true variable flow T-stat, so it starts opening at 185F, but doesn’t fully open at that temp. So it’s able to actually regulate the oil flow to the cooler as needed as temps rise/fall (and it can fully close as well should the engine oil get cooler, unlike the factory unit.)

It’s not a cheap by-pass or a simple lower-temp binary valve like other aftermarket suppliers offer. (which can result in too low oil temps).

[thejeremyman9]

Originally Posted by MTWO

85c is not the full operating oil temp for this car, thus what I said, is still valid.

Operating oil temp for the mol T-stat is 85C...

Originally Posted by visionaut

FWIW, the MSL Oil T-stat doesn’t affect my car coming up to temp, summer or winter. It gets to 220-230 almost as fast as before, it just doesn’t go over that now.

The factory oil T-stat opens at a higher temp, but it’s binary, so it’s either fully closed or fully open. When it opens, you get full flow from then on to the cooler.

The MSL is a true variable flow T-stat, so it starts opening at 185F, but doesn’t fully open at that temp. So it’s able to actually regulate the oil flow to the cooler as needed as temps rise/fall (and it can fully close as well should the engine oil get cooler, unlike the factory unit.)

It’s not a cheap by-pass or a simple lower-temp binary valve like other aftermarket suppliers offer. (which can result in too low oil temps).

Yup, exactly. I definitely wouldn't run the always open bypass valves.