P38A M51 coolant sensors

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RangeRoller dt

RangeRoller dt

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Hi all,
I've been to the motor factors to get a few things and, after the guy there trying his best in all fairness has left me more confused than ever, I have a question :

I have a 1995 BMW diesel.
I've got :
- 6x alloy inlet manifold gasket STC 2203
- a green ecu temp sensor STC 2299

What is the colour and part number of the other sensor that should be on my cylinder head?
I believe this is the one near injector1, above the fuel pump.

If anyone can Please answer this (with certainty) before I pick the parts up tomorrow, for what it is worth, you will have my Thanks and maybe this will be of help in future reference for others :)
 
Last edited:
RangeRoller dt said:
Hi all,
I've been to the motor factors to get a few things and after the guy there, trying his best in all fairness, has left me more confused than ever I have a question.

I have a 1995 BMW diesel.
I've got :
-6x alloy inlet manifold gaskets STC 2203
-green ecu temp sensor STC 2299

What is the colour and part number of the other sensor that should be on my cylinder head?
I believe this is the one near injector1, above the fuel pump.

If anyone can Please answer this (with certainty) before I pick the parts up tomorrow, for what it is worth, you will have my Thanks and maybe this will be of help in future reference for others :)
Click to expand...

On your car dash gauge sensor should be brown, there should also be a IAT sensor under front of manifold. ECU temp sensor as you say, gauge sensor STC2253 IAT sensor LR006796.
 
Spot on, Thankyou!
If your cylinder head was manufactured on/after the change point in 1999 you will have another 3rd sensor, not listed above, fitted to the very rear of the head.

It is black STC2254

and controls extra cooling function as a backup with the A/C fans.
If your engine does not have this - you do not need it :cool:

Engines with this black sensor typically have a black plastic inlet manifold instead. These can possibly be removed and reassembled without the need of new gaskets. If you do require them they are 6x STC4187

Hope this helps :)
 
RangeRoller dt said:
Spot on, Thankyou!
If your cylinder head was manufactured on/after the change point in 1999 you will have another 3rd sensor, not listed above, fitted to the very rear of the head.

It is black STC2254

and controls extra cooling function as a backup with the A/C fans.
If your engine does not have this - you do not need it :cool:

Engines with this black sensor typically have a black plastic inlet manifold instead. These can possibly be removed and reassembled without the need of new gaskets. If you do require them they are 6x STC4187

Hope this helps :)
Click to expand...

Black plastic manifold came in 1998 with EGR. Extra black switch in 1999 with over heat system.
 
If your vehicle is EGR -

1.)
You DO NOT need - IAT sensor LR006796. It's function is replaced by MAF.

2.)
The Brown (single wire) sensor mentioned above is instead a Blue (2 wire) sensor - STC (pending)
This Blue sensor is becoming increasingly discontinued and may be hard to source at a reasonable price.

2.b)
A possible alternative - I suggest only doing this if your blue sensor is a known problem AND completely unavailable.

It is possible to use an earlier Brown sensor in place of the original Blue, the green wire to the original must be connected to the single pin on the Brown replacement.
- DO NOT connect two wires together!
The remaining wire will not be needed at this point and can be blanked.
 
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Hi, could you explain where both wires would go,on the brown sensor. it sounds as if both wires are connected to the same terminal?
 
tarphenry said:
Hi, could you explain where both wires would go,on the brown sensor. it sounds as if both wires are connected to the same terminal?
Click to expand...

Your car should have a blue sensor. Two wires Green to pin 1 and Brown/yellow (ground) to pin 2. The brown sensor grounds to the head. DO NOT connect the two wires together. Providing Green wire on your two pin plug goes to single pin on Brown sensor it should work. There is some confusion in the 2000 version of RAVE which gives the location of gauge sensor as that for ECU sensor. If you look at 1997 RAVE it is more clear.
 
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once agan thanks. my gauge is working, and as per your advice, I have left the blue sensor alone. It was me not understanding what Range Roller had written.
 
Stc2203
image.jpg

These were £2 each and seem v.good quality.
20p ones are available but seem worse than cutting your own from a cereal box :p

Stc2299 / Stc2253
image.jpg

image.jpg
 
So this is weird. I should have a brown single pin sensor for gauge.

image.jpg

Green is correct, but blue? :confused: Plus it has two wires going to connector :confused::confused::confused:
image.jpg

Blue live seems to go to glowplug box, earth around front of engine in the loom. It should work fine now with either colour sensor with both wires but what puzzles me is why??:confused:

Has someone put in the extra wire, later type glow control box, tried to upgrade to blue sensor? Can't make sense of ito_O
 
RangeRoller dt said:
So this is weird. I should have a brown single pin sensor for gauge.

View attachment 173010
Green is correct, but blue? :confused: Plus it has two wires going to connector :confused::confused::confused:
View attachment 173011
Blue live seems to go to glowplug box, earth around front of engine in the loom. It should work fine now with either colour sensor with both wires but what puzzles me is why??:confused:

Has someone put in the extra wire, later type glow control box, tried to upgrade to blue sensor? Can't make sense of ito_O
Click to expand...

Not if you have aircon, it should be blue with aircon, brown without aircon. The brown sensor (one wire) grounds through it's body to head. The blue sensor (With aircon two wires) grounds back into the loom.
 
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Thank you @wammers you've pulled me out of the sh** once again :)
Only green sensor needed replacing it was just out of course I was changing other.
How you don't go mad telling people the same thing again and again amazes me.
I really do appreciate everything you've done for me :cool:
 
RangeRoller dt said:
Thank you @wammers you've pulled me out of the sh** once again :)
Only green sensor needed replacing it was just out of course I was changing other.
How you don't go mad telling people the same thing again and again amazes me.
I really do appreciate everything you've done for me :cool:
Click to expand...

I do from time to time sit here with a pair of underpants on my head a pencil in each nostril and a finger in each ear saying wibble wibble. :D:D
 
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