'91 318i M42 brown coolant temp sensor?

[E30-Wan Kenobi]

Where is this little bugger? I was looking this up on a few forums yesterday, and of course all of the pictures are either long gone, or don't show a zoomed out image to show what I'm supposed to be looking at. According to the diagram on RealOEM (diagram here: https://www.realoem.com/bmw/enUS/sho...diagId=11_4373 ) It says the single pin sensor that is supposed to send info to the gauge is number 6, and it looks like I would have to remove the intake manifold to get to it. What confuses me is that some people say you don't have to, some say you have to. Is it possible to not remove the intake and still reach the sensor? When I look for it from under the hood, I can't see ANY sensors. Is the OEM sensor brown like the aftermarket sensor? Part number is 12621710511 in case anyone needed it. I just can't seem to find it when I look inside the engine bay and don't want to have to remove a whole bunch of stuff just to replace this sensor...

[roguetoaster]

It is under the intake manifold, exactly where it's shown on RealOEM. While some may say you don't have to remove the intake I certainly would at least remove the upper section to get the electrical box that is under there out of the way. If you end up removing both parts of the intake you shouldn't need to disconnect the fuel lines to facilitate access.

If you just want to see the sensor just put your head above the oil filter and look aft/down. There you will see the oil pressure sensor on the filter housing, then a bit further back and near the block/head seam you will see both sensors a few inches apart.

It's also worth noting that gauge issues can often be a ground problem at the cluster, just depends on what you issue happens to be.

[E30-Wan Kenobi]

It is under the intake manifold, exactly where it's shown on RealOEM. While some may say you don't have to remove the intake I certainly would at least remove the upper section to get the electrical box that is under there out of the way. If you end up removing both parts of the intake you shouldn't need to disconnect the fuel lines to facilitate access.

If you just want to see the sensor just put your head above the oil filter and look aft/down. There you will see the oil pressure sensor on the filter housing, then a bit further back and near the block/head seam you will see both sensors a few inches apart.

It's also worth noting that gauge issues can often be a ground problem at the cluster, just depends on what you issue happens to be.

Awesome thanks, I'm going back out right now to see if I can get pics to help you help me, and hopefully help any other beginners with having to do this. I also made a little oopsie...kinda disconnected a radiator hose and a bunch of coolant came out before I could get it back on. Do I have to bleed the coolant system now? Does air get into the coolant system if I disconnect
a hose? I'm very new sorry. :(

Also the issue with the gauge is that it always shows it cold, like never moves from the beginning point of where it should be when the car is off.

[E30-Wan Kenobi]

OK so...after spending about 30 minutes trying to figure out where those sensors were, you said look aft (which I had to look up but I'm assuming you meant look towards the back of the car) and I saw 2 yellow-ish things that look like sensors and they were a few inches apart. And they were underneath the intake manifold. http://imgur.com/a/o0lDw

I'm assuming those are the sensors? I thought one was supposed to be blue, though. Maybe I'm wrong.

To find it I Put my head right above this oil filter like said, which is right here - http://imgur.com/a/Jx8SL

Then looked to my right, through the intake manifold.

Is this the electrical box that you were referring to?

http://imgur.com/a/Bayzj

I have to remove that because it's almost impossible to reach under the intake manifold to get there. I could still be looking in the wrong spot, though I'm not 100% sure. Heck, I'm not even 50% sure lol

[roguetoaster]

Air can get in to the system when you remove a coolant hose, bleeding an M42 has been covered many times on r3v in the M42 section.

The first pic shows your fuel injectors, second is the oil filter housing (shorthand is OFC for oil filter canister), and third is mostly your throttle body (centered in the pic) with intake boot (which is wrecked and needs to be replaced) in the foreground as well as your coil pack/spark plug wires in the background.


^Overview of the intake side.

^Detail of the sensors.

You can look through this album if you want more reference pictures: https://goo.gl/photos/Gc8eAgJXaYHQhXwS7

[E30-Wan Kenobi]

You are a god among men. This whole time I was looking for a brown plug and the dang thing that connects to the sensor is black. That's awesome though thank you so much I actually know where to look now! Gonna go try and change it, thanks again. I guess I'll look for more info on bleeding the coolant after I finish with this.

[roguetoaster]

Glad you found that info useful. While you may be a noob you were at least able to write in a reasonably clear way, and that's pretty much the key to getting help on r3v.

FYI posts about specific engines go in the engine specific subsections: http://www.r3vlimited.com/board/forumdisplay.php?f=144