Hey guys finished up doing the thermostat housing on my 2010 mcs a few days ago. I did a complete drain and fill. Who ever owned the car before me use green now I did the bleeding procedure and it seem to work good. Here's were I get the issue I picked up a scangauge 2 because I had a check light on after I changed the housing ended up being a p0117 and a p118b I believe. I noticed that when the car sits over night the temp reads -40F until it gets to around 180 and then the gauge will jump up and the car will start to run fine. Now I reset the codes and double checked the wires and ever thing looks ok but is the -40 normal when the car is cold? Or is the new temp sensor no good? I bought the aftermarket housing from Ecs tuning not the oe mini to much money.
I just noticed when I went out on break a few minutes ago that the car threw a p0117 again and the temp is jumping all around maybe the system is air bound?

 

Hello,

Check that temp sensor connection, if the tabs are loose the wires will give a false read. If its jumping around i think you still have air in the system and its not picking up the fluid or touching it. . I had to bleed mine about 3 times to get all the air out. Make sure the heater is on and you fill the expansion tank , while bleeding out that top screw, the screw has to come ot a bit, just watch the screw so it will not fall out on the last thread.

Then Bleed , bleed , bleed.

 

When you see a sensor at the extreme end if the range, I usually look for a unplugged clip, or a cut wire. Check first before you replace it.

 

So on lunch break I popped the res cap and cracked the bleed screw. A small amount of air came. So I topped it off and so far the temp seems to be ok I'll keep you guys posted when I get out and see how she does. Thanks for the fast reply everyone

 

Now the update at 2 I bleed the system again and it seemed to be straight coolant not bubbles topped off the coolant car seemed to be acting ok got out of work went to start the car and its reading -40 and it just turns over won't start. Took the intake back apart unplugged the temp sensor cleans the top of the sensor and the plug wth electrical cleaner and blew it and the sensor out put the car back together bleed the system again. Now the car tried to start stumbled for 10 seconds the temp then read 107 and now she runs fine. Do you guys think it's a bad temp sensor on a brand new thermostat housing?

 

I wonder if the wire harness has a split or cut into it when you pulled it back for install, you have to watch that harness near the edge of the block and near the HPFP. We had no issues with the housing and senor, see if its that first. If not then contact our CS and we can take care of you to get a sensor.

Move those wires around and try to start it, i bet there is a bad connection. This is the step were you can accidental chaff or splice a wire on metal.

https://www.northamericanmotoring.co...hermostat.html

 

That's a good possibility. I've been driving around most of the night. And now that it was cooled down I bleed it once more. Seem like there might have been just a few bubbles in it. I'll let it sit over night and if it still is an issue then I'm going to start going over the harness and trace the temp sensor wires. I tell you what the scangauge is a God sent to have but I ended up hooking it up to my fathers autel Maxiesys elite and it show a lot of old codes for things and the code for missing temp sensor signal. The only good thing is it was a stored code not active or pending hoping it was just the bad connecting

 

Ok every one now that I'm back home for nyc my babe is running perfect it must have been the lousy connection on the temp sensor. Alls well and good thanx for all the fast replays and help you guys are he bomb

 

You are welcome, glad that was it.