[e90Noobie]

Driving 40 mph my coolant temp is showing 123 degrees F. Now I don't know much about rocket appliances but this seems very cool to me. What is everyone's coolant temps at various speeds? Pretty sure my thermostat is shot. Idling the coolant temp rises to around 200 but that's obvious because there's no air going through the radiator.

[Persian Whisperjet]

That is low. Pls see: https://www.e90post.com/forums/showthread.php?t=1316966

[BlueHen335d]

These cars are 10+ years old. If your thermostat hasn't taken a dump yet, consider yourself extremely lucky. Sounds like your luck finally ran out.

[BB_cuda]

123F= 50.6C. That is coolest I’ve ever heard. I bet the whole thing is internally broke open...continuous flow. I’ve had better luck with genuine OE one holding close to 88C.

[e90Noobie]

I actually got the temp all the way down to 114F just cruising at 35mph.. I just started laughing at that point. Might as well see if we can get it any lower!

Anways, had the thermo replaced over the weekend. Temp now hovering around 197F. Reset my average MPG counter and got a steady 42mpg driving on the highway for 2 hours at around 70-80mph. MPG started out at 60 and then slowly dropped to 42.

[BB_cuda]

how are you reading 197F? app on phone? 197F is nearly 92C. That sounds high for cruising on freeway. Should be 88C/190F. I suppose there is a bit of variability but its winter time. If i let car idle a really long time, like 20 minutes, temp goes up to 97C and then rad fan comes on. Fan cycles between 95 and 97C. My car's T/S has degraded slightly to where it is at about 81C cruising on freeway.

[e90Noobie]

Originally Posted by BB_cuda

how are you reading 197F? app on phone? 197F is nearly 92C. That sounds high for cruising on freeway. Should be 88C/190F. I suppose there is a bit of variability but its winter time. If i let car idle a really long time, like 20 minutes, temp goes up to 97C and then rad fan comes on. Fan cycles between 95 and 97C. My car's T/S has degraded slightly to where it is at about 81C cruising on freeway.

I'm basing that number off of driving back to the house at about 45-60mph. I actually don't know what the highway temp was as I had to give the phone back with protool on it. Waiting for a micro USB OTG adapter so I can use my old Android tablet. I wish I had stuck with an android phone as Iphones aren't compatible with anything!!

[BB_cuda]

Google e90 cluster unlock. You can read your temp from the cluster using menu 7.

[e90Noobie]

Originally Posted by BB_cuda

Google e90 cluster unlock. You can read your temp from the cluster using menu 7.

I've tried it several times and it doesn't work for me. I do exactly what the tutorials say to do and it just goes back to the main screen.

[BB_cuda]

Did you enter in the code at menu 19? You sum up the numbers of last 5 digits of VIN.

[e90Noobie]

Originally Posted by BB_cuda

Did you enter in the code at menu 19? You sum up the numbers of last 5 digits of VIN.

Ahhh I was adding up the last 6 digits and now it works! Temp ranges from 86 - 91 C.

[BB_cuda]

Sounds like you are dialed into correct range now. Isn't that nice to get something for free ?

[e90Noobie]

Originally Posted by BB_cuda

Sounds like you are dialed into correct range now. Isn't that nice to get something for free ?

Well... it was far from free. I would have done the job myself but couldn't find any tuts on how to bleed the system and where a good drain point is.

The free advice was nice though, thanks

[BB_cuda]

I’ve posted here way long time ago about bleeding air out of the system. BMW tech taught me. Let it idle wither reservoir cap off. Coolant pees back into there with a fine stream. When you see no more bubbles in the stream, you’re done. Thermostat is $52-$60. We all have to pay for them every few years.

I didn’t drain any. I just let it spill a little when the T/S was removed. It needed maybe a quart of coolant added. I actually poured back in what I caught with catch pan and a little more from mixed jug.