E30 Zone

hi where is the blue sensor located on a m40 engine please.i refer to the blue sensor that can cause fuel issues and such.
cheers rich

Well hidden under the inlet manifold, just above the join between the cylinder head and the block.

This is a shot I took of mine: http://www.e30owners.com/forums/showpos ... ostcount=5

..it's the blue guy in the centre of shot down between the second inlet pipe from the front of the car and the intake boot (on the right of the photo).

can,t get photo up edna.and thanks brian.now do i need to take the inlet manifold off to replace it or can i do it without removing manifold.
thanks guys

Sorry, should have come up on the post I linked to...

I haven't changed my sensor yet but I'm hoping a deep, 19mm socket probably with an extension on the ratchet will do the trick rather than removing the inlet manifold. I think I read same on here somewhere...

Ednamillion wrote:Sorry, should have come up on the post I linked to...

I haven't changed my sensor yet but I'm hoping a deep, 19mm socket probably with an extension on the ratchet will do the trick rather than removing the inlet manifold. I think I read same on here somewhere...

You can certainly get to the blue sensor on an M50 this way,but I seem to remember having to invest in a deep 16mm socket!

19mm or 16mm which one.i think 19 sounds about rite

sorry if i sound stupid but i am new to E30s

What does the blue sensor do?

Is this any help?

http://media.photobucket.com/image/m40% ... sesors.jpg

beer wrote:sorry if i sound stupid but i am new to E30s

What does the blue sensor do?

No question is silly or stupid if you do not know the answer.

Blue sensor measures coolant temperature and relays the information to the engine ECU,thus determining the amount of fuel that the injectors fire into the engine.

They tend to fail 'safe',thus fooling the ECU into thinking that the engine is always cold.

As mentioned above,they are well hidden on the M40 engine,but sit in clear view on top of the thermostat housing on the M20.

threelander wrote:19mm or 16mm which one.i think 19 sounds about rite

Always...but always....defer to daimlerman regarding these things. I thought I read 19mm somewhere whereas daimlerman has actually carried out the work.

And I haven't.

sorry for the hijack but on an M10 injection, is the blue one the one next to the brown one at the front of the engine bay near the fuel pressure regulator?

m8782538 wrote:sorry for the hijack but on an M10 injection, is the blue one the one next to the brown one at the front of the engine bay near the fuel pressure regulator?

Can't say for an M10 but on my M50 they are right beside each other towards the front of the engine alright.

m8782538 wrote:sorry for the hijack but on an M10 injection, is the blue one the one next to the brown one at the front of the engine bay near the fuel pressure regulator?

This is where they are located on M20,which is an M10 with the cylinder count corrected....
But I have not owned/worked on an M10 engined car!

Yet again sorry to hijack another thread but could this be the solution to my problem also the temp gauge is vertually in the blue section

vendetta wrote:Yet again sorry to hijack another thread but could this be the solution to my problem also the temp gauge is vertually in the blue section

I had this problem in the winter. A new thermostat cured it.

Does the blue sensor have anything to do with duelling issues?

Blue sensor has everything to do with fuelling. If it, or it's wiring to the ECU is faulty, or if it's sitting in coolant at the wrong temperature, the fuelling will be incorrect.

So maybe if I change that it might solve my running problems

sorry for robbing my thread back but brian is there anyway to test the sensor while still fixed to the car ie lecci testers and stuff

You can measure the resistance between the lead from the sensor and earth at the ECU plug with the engine cold and at full working temperature. I would expect a reading of around 3500 - 4000 ohms cold (at current UK daytime temperatures) and 330 ohms at full temp.
Pull the plug off of the ECU, measure the resistance, push it back on, run the engine up to full temp., pull the plug off again, and immediately measure the resistance.
I can't advise you on the ECU pin, as my M40 engine circuit diagram has gone missing, but it's a brown/red wire.