c43 crank position sensor and cam position sensor

[andrewcliffe]

My C43 broke down on Friday in heavy rush hour traffic and once recovered started my research. From reading this forum and some others, it transpired crank position sensor was the most likely culprit, with the cam position sensor being the 2nd most likely.

Local Mercedes dealer had both parts on the shelf so bought both, on the understanding I could return one if unused. £ 160 for 2 small sensors is a lot!

Changed crank position sensor first - fairly easy on a C43, needs a short 1/2" imperial socket, with a universal joint and a long long extension.

So far, so good... Cam position sensor going back to MB today.

However both made by Bosch so you can order from a Bosch dealer and avoid MB prices for exactly the same part.

If you car takes the following MB parts, then here is the Bosch equivalent.

Crank Pos Sensor: MB 003 153 27 28 = Bosch 0 261 210 171
Cam pos sensor: MB 004 153 69 28 = Bosch 0 232 103 037

Hope this helps someone in the future...

 

[television]

Thanks for that info, and why not, pleased it was the crankshaft sensor, that is by far the most common

 

[grober]

Which does beg the question why a non moving part should breakdown at all??? I assume its a hall effect sensor or some sort of induction coil? Methinks "Ferdinand" has some questions to answer about doing things on the cheap?? OR Mercedes should be replacing them as a routine service item at a certain mileage /age.

 

[television]

Which does beg the question why a non moving part should breakdown at all??? I assume its a hall effect sensor or some sort of induction coil? Methinks "Ferdinand" has some questions to answer about doing things on the cheap?? OR Mercedes should be replacing them as a routine service item at a certain mileage /age.

It is the environment where these things live that causes them to break down, though sealed the expansion and contractions normally cause a break in the winding.

A bit of useless info.

When RR first started making ignition coils, the failure rate was quite high and the records showed that the faulty ones were all made around the 26th of every month. It was found that the girl who wound and soldered these things up was on her menstrual cycle around the 26th of every month. The acid produced in her skin eat through the fine secondary wire

 

[grober]

It is the environment where these things live that causes them to break down, though sealed the expansion and contractions normally cause a break in the winding.

I understand what you are saying but surely the fact these are going to be subjected to heat is not exactly going to come as a surprise to the manufacturer and its design/materials modified to cope. Wonder what their mean failure rate/operational life was when Ferdinand tested them to destruction in his development/test facility?? Or did he bother ----to tell MB. I wasn't aware of the ones in older models failing with the same regularity but could be mistaken on that.

 

[andrewcliffe]

Its a magnetic sensor, but living right next door to the exhaust manifolds means it gets subject to a huge range of temperatures which can't be good for it.

MB quoted me 2 hours labour to change it, but the job only took 20 minutes.

 

[television]

I understand what you are saying but surely the fact these are going to be subjected to heat is not exactly going to come as a surprise to the manufacturer and its design/materials modified to cope. Wonder what their mean failure rate/operational life was when Ferdinand tested them to destruction in his development/test facility?? Or did he bother ----to tell MB. I wasn't aware of the ones in older models failing with the same regularity but could be mistaken on that.

No you are correct in saying that. The 124's had a very low failure rate on this component, there again those engines in my view ran to cool at only 80c, modern MB cars run at 100c and that could make a difference, but you are correct in saying that it should not happen.

Is it not the situation where no one cares that much, modern soldering is wave or flow, all component soldered the same. If you bought a new TV and hand soldered up the power supply and components that resonate it would never go wrong.

I would like to take a faulty crankshaft sensor to bits to see what happened and why it failed

 

[television]

Its a magnetic sensor, but living right next door to the exhaust manifolds means it gets subject to a huge range of temperatures which can't be good for it.

MB quoted me 2 hours labour to change it, but the job only took 20 minutes.

Interesting that I have dealt with quite a few cars where this has happened in Spain and France while on holiday.

It is only a small coil of wire in a feroxcube housing

 

[Ultymate]

Just a note here to say that when a "camshaft" sensor fails it usually leads to delayed starting as opposed to non starting, If you keep cranking the engine for a while the ECU usually substitutes an average data figure for the cam and the engine will run but may go to limp home mode.

 

[grober]

Not exactly rocket science.

Again I accept completely what everyone has said. BUT there are are well established engineering procedures to cope with that. Programmed maintenance should easily eliminate the problem. Highly stressed component-short operational life= routine timed replacement. Mr Mercedes insists you change the oil/filter on a regular basis, why not this vital sensor? And at the same time not charge the "think of a number and quadruple it" price for a component that probably cost less than a tenner to make.
As they say its not rocket science.

 

[television]

Just a note here to say that when a "camshaft" sensor fails it usually leads to delayed starting as opposed to non starting, If you keep cranking the engine for a while the ECU usually substitutes an average data figure for the cam and the engine will run but may go to limp home mode.

This is why I will take one to bits one day, to see what goes wrong, oil or dirt does not upset flux. 1 short circuit turn will render it useless as will going open circuit, I will try and get hold of a faulty one

 

[television]

Again I accept completely what everyone has said. BUT there are are well established engineering procedures to cope with that. Programmed maintenance should easily eliminate the problem. Highly stressed component-short operational life= routine timed replacement. Mr Mercedes insists you change the oil/filter on a regular basis, why not this vital sensor? And at the same time not charge the "think of a number and quadruple it" price for a component that probably cost less than a tenner to make.
As they say its not rocket science.

Dead right, the cost must be under a £10 to make as Bosch made the unit and MB design their engines to fit this standard part. Almost a Microsoft situation

 

[kth286]

andrewcliffe

Good job it was the cheap sensor.

Did you check what the difference in prices were at Bosch ?

The problem is that if someone looks at the sensor just removed from the car and goes to Bosch for that part, they are not guaranteed to get the revised Mercedes spec. sensor.

You may not know it, but the spec of the sensor HAS indeed been revised since the early engine runs on the C43 cars. Yours is a different Merc part number from the early sensors for that engine.
You can only be guaranteed to get the latest spec by going to Mercedes first.

 

[andrewcliffe]

kth286 - thanks for the note. I guess you need to get the OEM part number from Mercedes and compare against mine.

I just got quotes from Bosch - crank position sensor part number no longer valid, but superceded to 0 261 210 170 and costs £ 39.12 (MB £ 47.66), and the cam position sensor is £ 64.90 (MB £ 94.85). All plus VAT.

 

[television]

kth286 - thanks for the note. I guess you need to get the OEM part number from Mercedes and compare against mine.

I just got quotes from Bosch - crank position sensor part number no longer valid, but superceded to 0 261 210 170 and costs £ 39.12 (MB £ 47.66), and the cam position sensor is £ 64.90 (MB £ 94.85). All plus VAT.

If I pay the postage is there any chance that I could have the old one so I can put it through some test

 

[andrewcliffe]

Sure - no probs - saves me throwing it away...

 

[kth286]

Just for comparison, the sensor for mine costs £71.06 + Vat (£83.50p).

Verses £56.

I guess that is why the 124's hardly ever go wrong.

Again, Mercedes building down to a price and all the attendant problems the later cars have.

 

[grober]

I believe HELLA make them as well? See the web cat http://www.hella.com/produktion/Hel...Service/Online_Catalogue/Online_Catalogue.jsp
part no 6PU 009 110-491 to engine no 60 002420

part no 6PU 009 110-501 from engine no 60 002421

 

[television]

I will make up a test set with a motor spinning and scope the output, with a heat gun I can warm it up and see what happens.

 

[andrewcliffe]

looking at the Hella site the only visual difference I can see is that my bosch / original MB sensor has a cable securing clip on one side (one of the long sides), wheras the Hella ones (according to the web catalogue) has two cable securing clips (both on the short sides of the connector block)

Television - if you email me ([email protected]) your address I'll send you my old sensor for your experimentation.