Cooling System

Originally Posted by SFbay

Look this is oem tstat
It's 99,6 C did not even move mm!
N62 will run at 92C which means bypassing radiator circuit only in Alaska

I noticed something the other night.. when I was on the freeway, and I gunned it, and really wound it out, it went from 103 to 92 instantly.. so that tstat can really open if the DME wants it to.. I wonder if the Alpina tstat is lower?

this was right after a highway run and some city driving, taken right after i parked.

no i actually didnt replace heater hoses, nothing after that duo valve, only things i didnt replace

ps wth is that 6 degree thing? that cannot possibly be correct.

Thats what I was wondering.. couldn't mean radiator cools it down to that low..

Originally Posted by cmpcpro

Thats what I was wondering.. couldn't mean radiator cools it down to that low..

If you step on gas dme opens up tstat fully plus your waterpump is on its max, so what's your question??
I removed tstat and it's equal to full open mode almost so my temp never went higher than 66! while driving.
Also tstat will open on its own when you keep high rpms: even with air in the system it will open tstat bc of too much flow.

Hey SFBay did you read my post RE Alpina? Whatcha think?

Final stage testing
Opens up at 95-96

This has probably been the most informative thread in this section for a long time and i haven't seen much response to it. It amazes me that the truth about important info with these cars' weak points doesn't get half the attention that aesthetic modifications get.
Then yet based off all of these i have seen for sale on CL hell even on cars.com etc i have noticed lots of little red cars on the mmi and a little engine shape on lots of kombis in their pictures. I guess owning a pretty car is more important than owning A car that is both aesthetically acceptable and fully functional?

Originally Posted by 745iguy

This has probably been the most informative threads in this section for a long time and i haven't seen much response to it. It amazes me that the truth about important info about these cars weak points doesn't get half the attention that aesthetic modifications get.
Then yet based off all of these i have seen for sale on CL hell even on cars.com etc i have noticed lots of little red cars on the mmi and a little engine shape on lots of kombis in their pictures. I guess owning a pretty car is more important than owning A car that is both aesthetically acceptable and fully functional?

Yep, nobody cares as long if it runs)
That's weird that 3 months ago nobody even showed a little interest for it, but now looks like ppl realized that e65 is not only about wheels
Gonna install modded tstat soon!!!
Should be no more than 96C before fan kicks in!!! Cross your fingers lol

I'm 200% sure all those leaks are related to high temp, otherwise e65 would cost much more than kbb says today!

Good luck this is definitely a mod that should be deemed necessary by e65 owners, i never even knew that the car ran that hot until i saw these threads and been watching them. My e420 4.2 v8 and c320 3.2 v6 didnt run anywhere near that hot and they let you watch the engine temp in the instr cluster

Originally Posted by SFbay

Final stage testing
Opens up at 95-96

Nice man, still not clear on the entire process here. How did you work out the heating element for the DME? Did you transplant a thermostat to the old housing? If so how many modifications required? Am wondering if we will get any underheating warnings or something similar.

Originally Posted by cmpcpro

Nice man, still not clear on the entire process here. How did you work out the heating element for the DME? Did you transplant a thermostat to the old housing? If so how many modifications required? Am wondering if we will get any underheating warnings or something similar.

Some update: as expected aux fan starts working at 96-97 and cools down to 94C. No error codes or anything, lets see how it goes I just drove 20mls or so and so far pretty happy with results. Will let you know with further testings.
Heating element was completely removed, otherwise it wouldn't fit.
There would be no warnings bc I installed the resistor for the DME.

Great!when do we get the DIY!!lol!SFbay are you gonna market this or can we have the plans for free

Sent from my M975 using Bimmer App

Originally Posted by dolfan13

Great!when do we get the DIY!!lol!SFbay are you gonna market this or can we have the plans for free

Sent from my M975 using Bimmer App

Still in testing so far wasted 300$ on various tstats!!! I hate BMW for this really! Imagine only if n62 and tranny would last 300k miles easy???
But I'm still thinking there might be some very small leak in my engine and bc temp is not that high anymore coolant is not boiling inside letting tstat to open. I'm assuming it's leaking from that rear engine plate, where you need to remove tranny to replace!!! Bc my mechanic found some small tears coming from bell housing and it was coolant;(
At least it's not overheating anymore and temp is nice! Just like in 6 inline

Good work sfbay you could be a bussy man if all the testing goes well. This should be a sticky or diy.

this time i took the screen with the engine running. this makes much more sense after highway driving, some city, and then idling for 10 minutes while i brought in some groceries
but i wonder if my tstat is different because my DME coding

Originally Posted by SFbay

Some update: as expected aux fan starts working at 96-97 and cools down to 94C. No error codes or anything, lets see how it goes I just drove 20mls or so and so far pretty happy with results. Will let you know with further testings.
Heating element was completely removed, otherwise it wouldn't fit.
There would be no warnings bc I installed the resistor for the DME.

this sounds promising

Originally Posted by 745iguy

this time i took the screen with the engine running. this makes much more sense after highway driving, some city, and then idling for 10 minutes while i brought in some groceries
but i wonder if my tstat is different because my DME coding

Is it after idling 10mins with heater off?? This is how mine was 2 months ago- nice and clean. Is it always 92?? It never even gets to 105???
This one is correct! This is how it should be 66 lower hose. But mine was 102-103 and lower 66
This is what I realized:
Just bc of very high tstat temp 105C lots of orings get flattened and even small sipping will cause pressure loss and if cooling system is not getting enough pressure the coolant inside will start boiling causing tstat not to open!! So now it's not getting to 100C so even if my car has some small leak its not getting to boiling point.
So... If your car gets to 107C and aux fan is not doing anything- you've got some leak very tiny, but enough to screw everything;(

Originally Posted by SFbay

Is it after idling 10mins with heater off?? This is how mine was 2 months ago- nice and clean. Is it always 92?? It never even gets to 105???
This one is correct! This is how it should be 66 lower hose. But mine was 102-103 and lower 66
This is what I realized:
Just bc of very high tstat temp 105C lots of orings get flattened and even small sipping will cause pressure loss and if cooling system is not getting enough pressure the coolant inside will start boiling causing tstat not to open!! So now it's not getting to 100C so even if my car has some small leak its not getting to boiling point.
So... If your car gets to 107C and aux fan is not doing anything- you've got some leak very tiny, but enough to screw everything;(

yes, heat off.. i realised the sensor readings were way wrong until i started the car, ive replaced all hoses besides heater hoses, coolant level is steady i see no bubbles as it runs either

Originally Posted by 745iguy

yes, heat off.. i realised the sensor readings were way wrong until i started the car, ive replaced all hoses besides heater hoses, coolant level is steady i see no bubbles as it runs either

So the screenshot was done when idling or not?? If not it explains why 92. Try checking it after driving for a while and in traffic when idling without heater and make a screenshot.

after driving a few miles on the highway, then city traffic and then taken while i was idling parked after i brought in groceries and before i went inside for good. heat was off

the first thing i posted with the 6 degrees and 101.25 was with the car off and it didnt seem right, drove then idled and thats what it reads, when i shut the car and look with ignition on and car off the readings are higher on coolant temp and much too low on output temp

Originally Posted by 745iguy

this time i took the screen with the engine running. this makes much more sense after highway driving, some city, and then idling for 10 minutes while i brought in some groceries
but i wonder if my tstat is different because my DME coding

So this is after driving freeway, and town, and traffic? 92c? See that's what I don't understand.. either your TSTAT is bad, your DME is opening the tstat way early because of a sensor or something, or your car is running super cool from the small coolant loop and not even using the lower radiator hose.. I don't understand how this could be.. only thing I can think sounds right, is either DME is opening it early, or do you happen to have an 02? I heard somewhere that the early 02's got a 92c tstat.. Or I should say the early N62 engines.

Thats correct
My 02 according to vin is 07/02 but i dont know about the early n62 thing personally

Also no tstat error code.