Salo

Which are usually leaking, Cam sensors or solenoids? Or is it both? I have seen both mentioned...

E55BOF

I don't know, but I definitely have/had a little oil at all four cam sensors.

kponti

Sensors have the leak. The sensors dip into oil on one end and connect to the ECU on the other end. When they leak, they carry the oil through wicking through the wiring harness to the ECU. That is when intermittent misfires not correctable by any method comes into play. And that is when you may need a new ecu and wiring harness

layzie12g

So why did you not check at the ME? I don't get it....

E55BOF

Tell me where the ME (whatever that is) is located, and I'll check it.

I've checked the camshaft position sensor connectors, and there is some oil there at all four. If it is wicking, I don't think the oil on mine has reached the ECU yet; the misfires are localised to specific cylinders, and they are entirely dependent on throttle position. (Anything up to about Warp Factor 6 is OK, but beyond that the Dilithium crystals cannae take it...)

kponti

That silver ribbed for her pleasure thing right smack in the middle of your engine. Has a bunch of wires going to it that is removed with a sliding clippy mechanism.

E55BOF

At last, a useful instruction. Thank you. Now I know what's being referred to, I think I can find a sliding clippy mechanism OK... MB use them a lot for securing multi-connectors into ECUs.

I'd still like to know what M.E. actually means, though; the simple acronym means nothing to me, and layzie12g hasn't been back on to tell me.

g60wall

E55BOF

Well, there you go. We don't generally use 'motor' over here to refer to internal combustion engines (you guessed it; that's the word we use...), only for externally-powered stuff like electric or hydraulic motors, so I didn't pick up on it.

"It's the computer that controls the engine (oh, look; you said 'engine'... ) functions'. No sh*t, Sherlock? (No offence intended).

Two nations separated by a common language, huh?

amgggg...

"ME" = Main Engine (Harness)

E55BOF

Thank you, one and all; I'd not have known about the camshaft position sensors design fault if it wasn't for this forum - until it caused a problem...

New plugs, three new coils (as indicated by the iCarsoft MBII), and the car runs normally again.

Four new camshaft position sensors fitted today, and the connectors both at the sensors and the ME (ECU) thoroughly cleaned out - aerosol contact cleaner, good blast with an air line, more contact cleaner, another good blast with the air line - and I reckon it should be fine (for a while). There was some oil at the ECU end of the harness, but there isn't now; I'll keep an eye on it for a while, to see if any more oil appears, but until the new sensors start to leak a little there's no more oil getting into the harness at the sensor end, so what's there now is under no pressure to migrate further (he said hopefully...).

Thank you once again.

PJmak

What you described in your first short paragraph happened to me.

Its a simple misfire.

Changed spark plugs and wires and fixed the issue for good

E55BOF

It did for me too, but since the leaky camshaft sensors are a known problem, and cheap enough to change, I figured it would be a good idea to do it.

I

E55BOF

A quick recap:

The initial problem was an intermittent ragged misfire under hard acceleration at high revs. Most of the time it did not occur under the same conditions.

There was oil at all four camshaft position sensor connectors, and at the ECU connector, so there was (and still will be) oil in the main engine harness.

The plugs had done 40K miles, so I fitted new ones.

I'm using an iCarsoft MBII as a diagnostic tool. The previous set of trouble codes (with the new plugs in) was for misfires on 5, 6 and 8. I fitted new (genuine MB) coils and leads on cylinders 5, 6 and 8.

I fitted four new (genuine MB) camshaft position sensors, and cleaned up/out (lots of contact cleaner, blow dry with an airline) all the oil at the camshaft position sensor and ECU connectors. It ran fine, pulled as it should, misfire gone, all in the garden was rosy......

Until today. I took it out, "Warp Factor Nine Mr Sulu", and the misfire is back. God, I hate intermittent faults!

It's a little different, though; the misfire was not ragged, but a single thump, something like I imagine the rev limiter kicking in might be, and it went straight into a sort of limp home mode - runs okay on minimal throttle, misfires on anything more, and misfires at idle.

The trouble codes are a little different, too. I drove home, switched off, plugged in the MB II, and now had misfires on 1, 5 and 8, all stored codes only.

There was no oil at the ECU connector.


I left the MB II plugged in, started the engine, ran the diagnostic, and now I had codes for:

Misfires on 1, 5 and 8 - all stored;

Stored code P069704 - "Output 3 for reference voltage of sensors electrical fault or open circuit. There is an internal fault".

Stored code P007012 - "Charge air temperature sensor cylinder bank 1 short circuit to ground. Short circuit to positive."


I left the MB II plugged in and took the car for a little run. It ran perfectly. One new, current, code appeared - P026A00 - "Charge cooling insufficient". There's a tear in the flexible inlet hose for cylinder bank one, which may account for that.

I can't find a decode anywhere for P069704. Does anybody know what it means? (Please God, not the nuclear - for the credit card - option, a new ECU...)

T_Cob

It could be a cooling issue, cylinders 1 & 5 sit right next to the turbos. I had misfires on cylinders 1 & 5, contacted my local AMG guy and he said if the car was low on gas (which it was, gas light was on) then a misfire could happen. Now I dont let go below a quarter tank.

E55BOF

Nearly full tank.

g60wall

E55BOF

I fitted Bosch, which are the OEM plug. If you buy the plugs from MB, you get the Bosch plugs in an MB box with a little MB logo on them, but that's the only difference - apart from the price...

I left the gaps alone, though; Bosch specifically warn against altering gaps on this type of plug, though I know the tuners do close them up a touch, but mine is a standard factory spec engine.

sjb

I had exactly the same issues you described, and finally managed to chase it down, with the help of the very diligent service team at my dealership. In my case it was a combination of two issues, but I would look into either (or both) if I were you.

ISSUE #1

CUSTOMER STATES CHECK ENGINE WARNING LIGHT COMES ON DISPLAY
,,,,TURBO CHARGED HOSE VACCUM LLEAK PERFORMED SHORT TEST -P1C800
,,,,CRANKCASE VENTILATION IN WIDE OPEN THROTTLE (CYLINNDER2) HAS A
,,,,MALFUNCTION , P030185 COMBUSTION MISFIRING OF CYLINDER 1 HAS BEEN
,,,,DETECTED // PERFORMED TEST PROGRAM - PERFORMED INTAKE VACUUM LEAK TEST
,,,,AS PER SDS FAULT CODE GUIDE TEST - : FOUND LEFT TURBO CHARGER BOOT
,,,,LOOSE CAUSING LEAK// SECURE TURBO CHARGER HOSE // CLEAR CODES//
,,,,RECHECKED TO VERIFY REPAIR : OK//


ISSUE #2

CUSTOMER STATES CHECK ENGINE WARNING LIGHT COMES ON DISPLAY CHECK AND ADVISE VEHICLE LOOSE POWER WHEN SET TO S+ MODE
CAUSE: VA
540650 ON-BOARD POWER SUPPLY VOLTAGE MAINTAIN (WHEN CHECKING/ TESTING AND TROUBLESHOOTING)
1955 W67
541011 PERFORM QUICK TEST
1955 W67
011203 COMPRESSION CHECK (SPARK PLUGS REMOVED)
1955 W67
151010 SPARK PLUGS, R & R / REPL. IF REQ.
1955 W67
079012 REMOVE/INSTALL RIGHT RAIL
1955 W67
1 256-070-01-87 A INJECTOR WITH NOZZLE
4 177-072-00-00 A TS SPRING F INJECTOR

,,,,45832 CYL 3 FUEL INJECTOR LEAKING CONNECTED SDS// PERFORMED QUICK,,,,TEST// FOUND CODES: P030185 Combustion misfiring of cylinder 1 has been
,,,,detected. There is a signal above the permissible limit value.,P030385
,,,,Combustion misfiring of cylinder 3 has been detected. There is a signal
,,,,above the permissible limit value.,P030085 Combustion misfiring has
,,,,been detected. There is a signal above the permissible limit value.//
,,,,PERFORMED SDS GUIDED TEST// PERFORMED SDS COMPRESSION CHECK
,,,,TEST//COMPRESSION CHECK OK// PERFORMED CHECK OF SELF ADJUSTMENT ACTUAL
,,,,VALUES// ACTUAL VALUES OK// PERFORMED CHECK OF HIGH PRESSURE FUEL//
,,,,FUEL SYSTEM HIGH PRESSURE CHECK OK// REMOVAL AND INSPECTION OF CYLINDER
,,,,1 & 3 SPARK PLUGS AND BORESCOPE INSPECTION NEEDED// REMOVED ENGINE
,,,,COVER AN RIGHT BANK ENGINE AIR FILTER HOUSING// REMOVED CYL 1 & 3
,,,,IGNITION COILS// REMOVED CYL 1 & 3 SPARK PLUGS// FOUND CYLINDER 3 SPARK
,,,,PLUG WAS FUEL FOULED// PERFORMED BORESCOPE INSPECTION OF CYLINDERS//
,,,,FOUND CYL 3 INJECTOR LEAKING// WHEN ANALYZING INJECTOR PERFORMANCE
,,,,DATA, FOUND CYL 3 INJECTOR DATA VALUES WERE OFF WHEN COMPARING WITH ,,,,REST OF INJECTOR VALUE DATA// DETERMINED REPLACEMENT OF CYL 3 FUEL
,,,,INJECTOR NEEDED// RELIEVED FUEL SYSTEM PRESSURE// DISCONNECTED ENGINE
,,,,HARNESS// REMOVED RIGHT BANK IGNITION COILS// REMOVED FUEL HIGH
,,,,PRESSURE LINES FROM FUEL DELIVERY RAIL// REMOVED RIGHT BANK FUEL
,,,,DELIVERY RAIL WITH INJECTORS // REMOVED AND REPLACED CYL 3 INJECTOR//
,,,,RESEALED INJECTORS(1-4)// RE INSTALLED FUEL RAIL WITH INJECTORS// RE
,,,,CONNECTED HIGH PRESSURE LINES// RE INSTALLED SPARK PLUGS, IGNITION
,,,,COILS AND ENGINE HARNESS// PERFORMED INJECTOR DATA TEACH-IN PROCESS//
,,,,ERASED FAULT CODES// PRESSURIZED FUEL SYSTEM AN INSPECTED FOR LEAKS//NO
,,,,LEAKS FOUND/// RE INSTALLED ENGINE AIR FILTER HOUSING AND COVER//
,,,,PERFORMED QC ROAD TEST(45822-45832) IN S+ MODE// CHECK ENGINE LONGER
,,,,ILLUMINATED// PERFORMED FINAL QUICK TEST// NO FURTHER CODES OR FAULTS
,,,,PRESENT.

E55BOF

And was your problem intermittent, and occurred in C mode? What was the mileage on your car? Did you have a ragged misfire on full throttle? Did your problem occur only at full throttle and high revs?

And incidentally, none of the plugs I took out were fuel fouled.

sjb

• intermittent
• never occurred in C, but I rarely drive around in it, and definitely never at WOT
• started at around 15,000 until it was finally resolved at around 59,000
• yes, misfire always happened at full throttle
• yes, WOT and high revs

E55BOF

Wow! It took 45k miles to get it sorted. I wonder what the problem was when it started? I suspect you had one problem, then the other started; simultaneous faults don't often occur.

How many tries did you have to get it fixed before it was finally resolved? Were the injector values checked early on in the fault-finding process, because that information would have shown that one of them was reading out differently to the other seven.

Is your car tuned, or stock?

And finally, how can you be sure it is fixed? If it's an intermittent fault, you only know it hasn't come back - yet...

E55BOF

Not the same as my problem, though; I had random misfires on more than one cylinder, in both cylinder banks, and no fuel fouling on any of the plugs.

If you had random misfires on more than one cylinder, then replacing the No. 3 injector could not have fixed the problem, and it would return; if you had random misfires on cylinders in the other bank (5 to 8), then tightening up the turbo hose connection for the 1-4 bank would not affect those either.

My problem was a broken wire, intermittently breaking contact and on one occasion shorting out, in the loom to the interchanger coolant pump. Once my independent found that, it all fell into place.

My problem is fixed; I hope yours is too.

Blk Betty

Sorry to bring up old threads, but what wire was loose. I recently got a tune on my 14 E550 and am having the same issue. Changed the plugs, checked for exhaust leaks, intake leaks and loss of power around 2K rpm consistently. Stumbles and jerks at 2K rpms after about 45 mph. I have down pipes, tune and E63 mufflers.

E55BOF

It wasn't a loose wire, it was a broken wire in the intercooler loom. If you have the non-turbo engine, you don't have an intercooler. You also have very different symptoms to those I had, so you do not have the same problem. Sorry, but I can't help.

Take your car back to the guy who did the tune and ask him to diagnose the problem.