Crankshaft position sensor failed. Higher repair cost than expected!

[DSM10000]

I had a sudden engine cut-out yesterday in the C320, fortunately I had just left the motorway and was negotiating a small roundabout when it happened. The steering does become rather heavy and the brakes quickly unresponsive with no powered assistance!

I carry a Bluetooth OBD Scanner with me and have the Torque app on my mobile 'phone so I was able to find out what the Check engine light symbol was indicating, I quickly got the code PO335 for Crankshaft Position Sensor.

The car did re-start after waiting 15 minutes but as it would certainly happen again and possibly in a less convenient place to pull over I called the Breakdown Service (Green Flag, very good response and good communications) who recovered the car back to a local garage I use near Salisbury.

The car was ready by 1pm today with a new MB supplied CPS but with an invoice showing 3 hours labour, one hour was for diagnostics, checking wiring loom etc with 2 hours to fit it as it is, apparently, in a very awkward position. The part was £103.30 from MB with the invoice amounting to £332.44.

Obviously it had to be fixed and in the scheme of things the total is not outrageous but I am surprised fitting took 2 hours.

As an aside, the car does feel smoother and more responsive and the car was washed and vacuumed!

 

[BTB 500]

Replacing the CPS on my V6 Vito cost £377, but that included two M-B engineer callouts (as the van was dead and couldn't drive) - one to diagnose and the other to fit. The latter took about 5 minutes with the vehicle on my drive, done from underneath. The diagnosis took about 20 mins, again with the vehicle on my drive. So 3 hours labour in a garage does sound a bit excessive.

I don't know what year or mileage your car is but there was an MB safety recall in November 2008 to replace the CPS on all OM642 V6 CDI engines built during 2006 and 2007 (manufacturing defect):

Recall Details for MERCEDES BENZ - M, C, CLK, E, CLS, S, R & G- CLASSES.

Bizarrely the W639 Vito & Viano was excluded from this recall. I tried for a goodwill payment from MB UK as it was a known fault, I'd owned the vehicle from new (it had only done 62k miles), and it had FMBSH ... but no dice.

 

[DSM10000]

Replacing the CPS on my V6 Vito cost £377, but that included two M-B engineer callouts (as the van was dead and couldn't drive) - one to diagnose and the other to fit. The latter took about 5 minutes with the vehicle on my drive, done from underneath. The diagnosis took about 20 mins, again with the vehicle on my drive. So 3 hours labour in a garage does sound a bit excessive.

I don't know what year or mileage your car is but there was an MB safety recall in November 2008 to replace the CPS on all OM642 V6 CDI engines built during 2006 and 2007 (manufacturing defect):

Recall Details for MERCEDES BENZ - M, C, CLK, E, CLS, S, R & G- CLASSES.

Bizarrely the W639 Vito & Viano was excluded from this recall. I tried for a goodwill payment from MB UK as it was a known fault, I'd owned the vehicle from new (it had only done 62k miles), and it had FMBSH ... but no dice.

Mine has the M112 V6 Petrol engine.

They charge an hours labour for any diagnostic and they did check the wiring to ensure it was not damaged and the loom is also difficult to access and inspect apparently. They did say they had to use the mechanic with the slimmest arms to get to it!

Perhaps MB placed the CPS in a more accessible place on the V6 Diesel or access is just better on the Vito?

 

[jaymanek]

Excessive in my opinion. It is awkward to do but as a garage, we charge book times.

From memory the "autodata" labour time for those sensors is 0.5 hours.

I dont think a general mechanic could do it in that time unless they do it regularly, however 2 hours is excessive.

We charge a flat diagnostic fee, usually £35.

Normally if we are doing the job we waive the initial diagnostic fee but min labour time is normally one hour.

From my point of view it should have been 1 hour + the sensor and possibly a reasonable diagnostic fee.

 

[Will]

Crank sensor is held in with one bolt, one connector and pulls out.

I’ve changed one on a V6 320 in a W210 and a V8 (5.4) in a CLK. Both with basic hand tools (1/4” drive socket set and extensions) from above - no jacking up or other dismantling work required.

Both simple jobs but the V8 engine in the CLK meant it was a bit tight, I think 20/30 minutes work tops though. If you’re working in a garage I would have thought less time not more?

2 hours seems excessive IMHO unless there’s anything else that wasn’t mentioned?

 

[markjay]

There's always the possibility that they just don't know how to do this.... i.e. they put the car on a lift and removed the exhaust downpipe and an engine mount for access or other such likes etc....

 

[Tuercas viejas]

Excessive in my opinion. It is awkward to do but as a garage, we charge book times.

From memory the "autodata" labour time for those sensors is 0.5 hours.

I dont think a general mechanic could do it in that time unless they do it regularly, however 2 hours is excessive.

We charge a flat diagnostic fee, usually £35.

Normally if we are doing the job we waive the initial diagnostic fee but min labour time is normally one hour.

From my point of view it should have been 1 hour + the sensor and possibly a reasonable diagnostic fee.

As a shop owner this is a fairly common issue on many vehicles not just MB's with Bosch equipment!
Being a hall effect sensor they do fail and heat is not their friend!
On all 4/5 banger common rail MB engines (incl Sprinters) they just cause an abrupt cut as described at lower revs simply because the CPS excites the PCM and it goes dead. And yes 15 to 30 minutes standing usually gives you a restart .
Now on all 4/5/6 banger engines the shop time quote I hour basically taken from auto shop estimator times which includes setting up.
In US $ the sensor is $185, a pretty universal charge across the board charge for a MB genuine part .
Yes the use of a scan tool might give you a charge but for a simple CPS change out we don't charge diagnostics for that -BUT
If the sensor is stuck in the block by corrosion then the labor charge can be as much as 5.5 hours to slip the transmission back and pound out the sensor from the corroded port.
Equally it is not uncommon to come across and errant sensor signaling which is NOT the sensor but a harness/flex plate issue .
In these cases we do use the scan tools and an oscilloscope to plot the saw tool waveform and prove the source of failure.
In these cases we charge $125 for diagnostic work .
Tuercas viejas

 

[DSM10000]

In this case it was a simple diagnosis (one I had already given them but I understand that they wanted to check it), I believe they were not familiar with the engine and procedure and had difficulty physically reaching the part as they told me they had to use the mechanic with the thinnest arms.

They are a good general garage but not an MB Specialist, I have only used them previously for tyre fitting (they work for Blackcircles) and have found them pleasant, attentive and easy to deal with so I thought I would try them with a repair.

 

[Tuercas viejas]

DSM10000
Yes well that is where platform familiarity comes into play.
These are what you would call pattern failures & their symptoms fall into a category you become accustomed to with a specific brand or model. When a customer calls in with roadside failure or it turns up on the hook as a no start there is often a casual bet amongst the techs as to what it the likely cause of the failure .
What is interesting is the pattern of failure symptoms leading up to total shut down.
For some reason MB's seem to run once the engine is operating at speed but when you come down to a stop light, roundabout etc is looses its signal abruptly at low engine speed and it's a no go! .
By comparison on a V8 petrol Landrover with Bosch equipment the first sign is an engine stumble at speed taking place several times before it stops dead!
This happens with more frequency after 90,000 miles, so you tend to recommend a change out of the sensor at a 90k service interval to avoid a roadside breakdown!

I suppose the head scratcher is say a customer's Audi A4 my brother was working on in his shop in Gloucestershire. A simple CPS sensor change and a similar no start. Simple no big deal issue yes? --Well NO! The car would run for a few seconds then abruptly shut down!. Brainstorming it over the phone my suggestion was to hook it up to an oscilloscope. Sure enough it was found!
The sensor was an aftermarket Chinese copy and the wave form was clipped! It would run on an initial start but the signal would not allow an ECM synchronization with the cam sensors so it would shut down. Leaving everyone baffled!
Turned out the genuine part in a genuine box he purchased from the local dealer was in fact an aftermarket sensor simply into a genuine box and returned by a previous customer! Surreptitiously slipped into the box which appeared to be unopened.
So DIY'rs beware!-check the contents and the sensor itself .
Tuercas viejas

 

[BTB 500]

Mine has the M112 V6 Petrol engine.

Oops ... sorry! So used to seeing 320 used (wrongly) without the "CDI"

Perhaps MB placed the CPS in a more accessible place on the V6 Diesel or access is just better on the Vito?

The Vito probably has a bit more ground clearance than some M-Bs with the OM642 (not the ML though!), which may have been a factor. The guy (proper M-B mechanic) just slid under it on my drive and it was done in a couple of minutes. But I suspect knowing exactly where it is, how it's retained, etc. is a factor too.

I was most annoyed that M-B considered the engine cutting out with no warning to be a safety issue on all their models apart from the Vito and Viano. With these defective CPS units once they failed that was it - the engine wouldn't fire at all (not temperature related). In other countries the W639 was included in the recall (as you'd expect) - it was only excluded in the UK!

 

[WG M-B]

If it's a w203 then it is a fiddly job. Really tight in there

 

[DSM10000]

If it's a w203 then it is a fiddly job. Really tight in there

It is a W203 V6

 

[Mark F6233]

Is there a way you can find out from the vin number if the recall has been done. I have a 2006 R320CDi?

 

[Gbrowncls55]

When my CP's failed on my v6 r230 SL iin the middle of nowhere, I called out the RAC. I got a taxi to the dealer 4miles to buy the part and the RAC Man fitted it at the roadside.....took him about an hour . it is in an awkward place to get at. Last of the old school roadside assistance men?

 

[BTB 500]

Is there a way you can find out from the vin number if the recall has been done. I have a 2006 R320CDi?

Unless your car is very low mileage for its age I think it would have failed by now if the recall hadn't been done. A dealer might be able to find out though - I assume M-B would have records.

 

[Mark F6233]

Unless your car is very low mileage for its age I think it would have failed by now if the recall hadn't been done. A dealer might be able to find out though - I assume M-B would have records.

The R class has only done 80K. It's absolutely mint, not a mark on it.

 

[BTB 500]

The R class has only done 80K. It's absolutely mint, not a mark on it.

The recall was in 2008 so they must have started failing prior to that. My CPS went at 62k miles ... I've owned the vehicle from new, so I know it was the original one. I'd be surprised if one with a manufacturing fault lasted 80k miles, but the only way to know is to ask MB.

 

[Mark F6233]

The recall was in 2008 so they must have started failing prior to that. My CPS went at 62k miles ... I've owned the vehicle from new, so I know it was the original one. I'd be surprised if one with a manufacturing fault lasted 80k miles, but the only way to know is to ask MB.

Thanks, will ask the local dealer.

 

[lily]

An OBD scanner is necessary for saving money and time.

 

[DSM10000]

An OBD scanner is necessary for saving money and time.

An interesting first post, are you selling theses?