2010 gl550,
has permanent cyl 1 and 4 missfire
also bank one intake and exhaust over retard faults won’t clear, everything is plugged in and look good
when starts cold seems to run fine for 10/15 seconds then miss shows up
swapped coils around etc no real change
cyl one is firing weaker than 2 and 3 but it is firing
cyl 4 doing nothing
many ideas? Thinking maybe fuel injectors or something with the fuel supply
thx guys I’m new to this engine

 

What exactly are the DTC's?

 

thank you
-P0304 permanent cyl4 missfire
-P0300 permanent random missfire
-P0012 permanent intake cam position time over retard bank 1
-P0301 permanent cyl1 missfire
-P0015 permanent exhaust cam position timing over retard bank 1
I’ve tried to clear with code reader and unhooked battery over night all remains
I swapped plugs and coils from 2/3 to 1/4 acts the same
cyl 1 is hitting, I pull the coil connector and engine changes, not as noticeable as cyl 2 and 3 but there is a change
when pulling cyl4 connector no change so it’s for sure not hitting
any ideas? I’m almost thinking injector is bad

 

You have to clear the P030x DTCs after swapping coils. I would simply get a couple of spare coils and install them on 1 and 4; clear the DTCs and retry.

If you want to test the coil operation, just pull a spark plug and put the coil on it, grounding the body of the spark plug. When you crank the motor you will see the coil spark.

If you do not clear the DTCs, the system will limp along before the retrying the suspect cylinders, maybe several drive cycles. I believe the ECU keeps the injectors shut off so as not to dump unburned fuel into the cats. When it gets the misfire error, you cannot tell whether the coil has stopped working or the injector has been shut off. The system diagnoses misfire purely by looking at variations in engine speed, so many things can cause the P030x DTC. P0300 errors often result from the motor struggling in limp mode, so often can be ignored until the other root causes are repaired.

Fuel injectors often fail gradually, by getting clogged. Coils typically go intermittent complete failure until they stop working entirely.

You can hear if the injector is activated by doing the screwdriver-stethoscope trick. Should hear a regular ticking from the injector body.

The cam timing errors are rectified by swapping out the cam magnets with new vintage. Or you have significant timing chain problems on bank 1 - the timing chain has skipped a tooth, or is stretched, etc. If you had problems with your bank 1 cams, you would likely have problems all along bank 1. You can check out the part numbers of the cam magnet sensors, but I would get the misfire errors straightened out first.

 

thank you, I did get 2 spare coils and installed but the codes will not clear.. my machine says all codes cleared then re connects and all the same show back up permanent.. I tried unhooking battery same thing
i do need to try the plug on the block idea to see if they even sparking
strangely it seems to run well under load, I can take it out and accelerate it doesn’t miss a beat but at idle you feel it miss

 

So you replaced coils 1 and 4 with new, and P0301 and P0304 return?

Even if you don't clear the errors, they should self clear on drive cycles. Your tool MIGHT not be adequately clearing the codes, just the CEL setting.

Pull the spark plugs and visually confirm sparking on 1 and 4. While you are at it, do a visual inspection of the rest of the plugs.

If you get a good tool, like the Autel MP808 or better, you can disable individual fuel injectors to check for their functioning.

Warning: Pulling the fuel injectors is a pain. Clean thoroughly the top of the intake manifold or you will drag dirt inside when you reassemble. Do whatever you can to avoid pulling the fuel rail. I spent a couple of hours with oil soaked Q tips picking up the sand and junk trapped around the fuel injectors because I was stupid and did not clean the top first.

You can get pretty good traction cleaning the fuel injectors with fuel additives; get ones with high PEA and naphtha content. Gumout Regane Complete has something like 30% PEA.

 

yes I pulled all plugs on that bank and they all appeared the same lightly grayish color so I believe they are all firing
the faults will not clear by my handheld or battery disconnect
maybe that’s it the faults are preventing the ECU for activating the fuel injection
now just to figure out a way to clear these faults
I did inspect the injectors just to confirm connected/etc and yes they have quite a bit of buildup on them I see what you mean

 

If you are going to be living long term with this truck, you really ought to have a good tool, like Autel MP808 or better (e.g. STAR). The ability to interact directly with the ECU will be a lifesaver. I would not be surprised to find that your tool is simply sending the generic instruction to the ECU to remove the "stored" codes, but in my experience the ECU will go into cripple mode without storing (illuminating CEL) a code. If you query the ECU, you will find those codes are still there - and the motor is still running in limp mode.

You ultimately will benefit from a "bidirectional" tool. The iCarsoft MBII will query the ECU directly, and will probably do a deep clearing of codes, but almost certainly you will sooner or later be plunking down the cash for a better tool anyway.

Torque (the cell phone app) will show pending codes as well as stored, and might clear these to the ECU's satisfaction. But long term you will be kicking yourself for not getting a better tool.

 

DAS beste oder nichts.

i swear by my DAS Xentry MbStar clone I’ve now had for 6 yrs. Have saved about that many thousands in dealer fees.

 

I looked into those, but found them intimidating. Don't you have to have a particular laptop or something? I thought they had a limited lifetime - but it sounds like yours has lived well.

I find WIS a giant pain to use and have to confess I am afraid of MB software.

 

Yes I have a giant brick of an outdated Dell laptop that I run it on, but once you get into it it’s actually very straightforward it’s just like in Autel except that you’re interfacing with a PC that’s hooked to a clunky MUX and you need an extension cord piped in to run everything.
Obviously the PC and the cloned software came from China and has malware and viruses all over it so I’ve never hooked it up to the Intermat and it will not handle newer than 2013 vehicles but I’m OK with that. No adverse effects on the vehicle.

Developer mode is what really makes enduring the obsolete setup worth it. To my knowledge developer mode is not available in any other system and it is just such a useful tool. Don’t need TPMS? Turn it off. Don’t want secondary air injection? Turn it off. Don’t want a broken intake flap valve to trigger a check engine light? Well turn that **** off too. Tell your ECU that it now has a 550 motor instead of a 450 motor? Sure can do. If I learn enough German I might be able to figure out whether I can do a vehicle speed sensor reprogram of the valve body myself, rather than have to send it out or take it to the dealer.

 

I can't even update firmware on my router without bricking it.

Autel has various coding features but I doubt it has a developer mode.

 

Do you have to tell the ECU it is a 550? Or does it self adapt? Reason I ask is I am likely sending my ECU back to Pressertech for feature trimming, and in case I end up putting in a E55 I would like to know whether I will need another go-round of work.

It is a pain to mail the ECU to Georgia and back, but at this point I really do not trust myself with MB software's Developer Mode.

(OP sorry for taking your thread off topic, but it's probably worthwhile to learn what the tools can do.)

 

Dude if you can get an m113k (e55) into the gl you’re a hero. 💪

oh, you’re talking about the other m272 motor…bah.

i don’t know if it’s strictly necessary but there is an option on developer mode under Motor Electronics where you can select the e47 or e55 sub variant in the Steuergerät or something to that effect pulldown.

sorry OP you’ve been foisted.

 

Other M273 motor

Yeah I was being a showoff. I just thought it was cool that the variants have their own names.

Dang I'm starting to talk myself into getting a DAS. They sell 'em with Panasonic Toughbooks now. Probably eminently resellable. I want to tinker with getting rid of other items on that motor. I hate the auxiliary air pump, for example, sitting there on the front of the motor like a giant turd. Also can't stand the tumble flaps; people lived many lifetimes without intake manifolds with clunky junk stuck all over them to vary the length of the intake runners and turbulize the intake air. I'm ticked because I broke the little vacuum solenoid on the front trying to get the manifold back in and now I want blood.

Plus Pressertech is taking their time getting back to me on stripping the junk from my ECU.

 

Back to the point I verified the plug was sparking so I’m at a loss
all I can think is the injector isn’t firing correct
I bought a icarsoft mb11 and got the faults to clear
so when cleared it seems to idle better but still a miss.. SES light stays off for a while but it slowly returns the idle gets rougher and then the SES light comes on
now it’s just cyl4 miss with random misfires
still shows the “B camshaft position timing over retarded bank 1”
local MB says check compression possible bad head
so what is the correct process to accurately check compression on bank 1?
pull all 4 plugs throttle open ?
im new to this
can I just independently pull each plug and test that cyl the reinstall plug and move to the next ?
seems a low comp would be obvious
thx guys

 

You can run a compression check with a compatible scan tool like xentry - not sure if the aftermarket scanners can do this. If not that, I don’t see why you can’t do an oldschool comp/leakdown test on a warmed up motor.

 

What DTCs do you get now? List them, and all the information that MBII is showing you. Note that the ECU aggregates a range of MB-specific codes into one OBD code. For example, your P0304 can consist of a number of sub-codes rolled up into one. I do not remember whether MBII shows the ECU sub-codes.

If you are still getting a misfire code, the motor will idle distinctly poorly because (I believe) the ECU shuts off fuel to that cylinder.

You need a [more expensive] bidirectional diagnostic tool to automatically run the compression test. That is also a less informative test, because it only shows max-min, not absolute levels. The ECU has no direct measurement of chamber pressure.

The old school compression test is obviously more laborious. Take out the spark plugs and the fuel pump relay or fuse, and have an assistant crank the motor. You are looking for about 165 psi. It is difficult to do well because that is a lot of pressure to hold back without a screw-in pressure fitting.

A compression test is not the first diagnostic I would do, but it is a most useful benchmark of engine health.

Spend some time with your MBII poking around the ECU queries.