W204 C220 Blue Efficiency B19/11 EGT sensor with EURO 5 adapter A6511530056

[whitegold]

Hello all, I wonder if some kind person with WIS access could post the Torque setting for the Exhaust Manifold Connector A6511530056 which sits between the EGT sensor and the manifold?
Apparently this spacer is used in EURO 5 Sprinter Vans as well as the Blue Efficiency cars with OM651 etc.
I understand the sensor itself should be 45NM but can't find any reference to the spacer which screws directly into the manifold without a gasket.
Reading some other posts on changing theis sensor, it seems to get seized into the connector, and can only be loosened with the connector in a vice. That was my experience, however it was so tight that even when heated and held in a vice, it was immobile and eventually broke off.

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[steveq]

When I changed the EGT sensor on my C220 Blue efficiency, the spacer complete with the old sensor unbolted from the manifold but I struggled to unbolt the old sensor from the spacer.
It was all so welded together that I thought it was all one unit and the dealership parts department had sold me the wrong new sensor.
I brought the old and new back to them. The parts guy brought the lot to a mechanic to ask him. He was good enough to split the spacer from the old sensor using a vice and spanner but I didn't see him doing it. The parts guy brought it back to me in just a few minutes so it can't have been too difficult.

When I fitted the new spacer and sensor I just bolted them into the manifold tight enough without swinging out of the spanner.
The hardest part was routing the sensor cable across the front of the engine and into the connector.

 

[whitegold]

Thanks for the reply. Both the sensor gland nut and spacer are Stainless steel, which probably accounts for why they lock so fiercely tight together. Sadly, heating, vice and strong arm didn’t work for me; the gland nut sheared off.
If I was doing this again, I’d order a spacer as well as the sensor. It was less than £9 from MB Truck and Van dealer.

 

[steveq]

Did you try to drill out the old sensor from the spacer?

However, I see that you have the new spacer now and at £9 it is a cheap solution.

I don't think I put any ceramic or copper grease on the threads of the sensor or the spacer but it probably is a good idea so that they don't seize up again.

 

[whitegold]

Apologies for the late reply, Steveq. Yes I did attempt drilling out the old sensor - I cut a groove into it with a die grinder, which released it OK, but the new sensor was feeling like it was starting to pick up while being screwed in, so I didn't think it was worth trashing a new sensor if it seized up half way. And as I mentioned it was only £9 odd for a new spacer.
Annoyingly the P054615 re-appeared intermittently after a couple of months, and is now showing 1200F all the time.
I believe there is also a common wiring fault mentioned in TIPS but my MB Info is sadly too outdated. I'm going to check out the resistance of the sensor, which will mean stripping out the wiring harness and gives me a chance to have a good look at the sealed connectors.

If the fault is on the ECU side of the harness, it's going to be a challenge. I wonder if the connectors are available seperately from MB? I don't imagine they replace the whole engine harness for a single connector fault.

 

[steveq]

It is unlucky if the new sensor has gone faulty so soon.
Did you buy a genuine Merc sensor the last time?

If is is permanently showing 1200F then it sounds like it is faulty.
I was told that there was a TIPS note regarding a problem with the wiring. I simply replaced the sensor on mine and it has worked perfectly since so didn't follow up on the potential wiring issue.

Could you try re-seating the connection where the sensor wire joins the other wires at the front of the engine?

 

[whitegold]

Still rumbling on with this issue, the £60 odd Ridex 3938E0052 sensor obtained from Autodoc on their recommendation, worked for a while then went open circuit.
(Warranty claim in progress, looks like they will refund) ****EDITED ***Update that Autodoc have now accepted Warranty claim, Happy Days
Now replaced with the genuine MB part, which indicates sensible levels.

 

[steveq]

I looked back at my records and see that I replaced mine with a genuine MB sensor over 5 years ago and it has been fine since then.

I assume that MB don't actually manufacture them but they probably do define the specification and quality.

 

[whitegold]

So the next annoyance to be tackled is the DPF Regen now blocked due to soot too high. I'm going to start a new thread for this, as it's a topic scattered all over the interweb with conflicting info.