Pls someone shed some light on this. I blasted that twice as much as the others. Hey fin, I've just done a bit more updating to my earlier post. Compression test along with ignition testing, smoke test to check for vacuum leaks, new valve covers and gaskets, sensors tested with no issues and they cannot seem to come up with a solution. The resistance value should be between 25-35ohms, anything different means the valve is defective! I reckon I have a faulty check valve.
These, in turn, are greatly affected by the degree to which the cylinder is filled and the geometric form of the intake tract. I have not seen my issue listed here, but so many others have similar cases. The central pivot was hanging up on the pivot screw. Next picture shows the vacuum connection to the plunger indicated by red circle. I did get a part number for it from the stealership and I have noticed that the car doesn't have the same power it used to, but not as bad as limp mode. The likely failure of the valves is due to the internal parts of the manifold being both old and brittle, as well as gummed up due to gunk buildup on the various moving components, causing them to hang up and stick and eventually break.
Closer view in the next picture. Sorry I've not been back to this post for a while. You will lose power, misfire, and most likely get a check engine light for Mercedes fault code P2004-P2007. So, as we are all now aware. I've since spoken to another tuner who suggested using a change over relay to get it to work with the haltech. I've got one on order.
Be careful, its right next to the turbocharger, down low, and is easily confused with the vacuum line or electrical wire going to the turbocharger, to another valve on the firewall N75, I think! Red arrow is the connection plug for the secondary air pump solenoid that comes directly from the pump. The intake manifold sounds to be the likely culprit, but often my experience with these matters yields something totally out of left field to be the actual cause, like a problem with the secondary air pump or a bad tank of fuel damaging the fuel system. The latter being the easiest of the tasks,, of course. For now though, I really have to sign out. When driving normally the gauge will show a small amount of vacuum or move to show a positive pressure i. So it seems to be once I take load off that something gets triggered or malfunctions to flog the engine light. I check torque once more to allow for bolt stretch.
If specification is obtained, check voltage supply. Is the intake manifold the same? All the other links and both flap assemblies inside the manifold were free and moving easily. I ordered the kite with the repair kit with intake gaskets. The yellow circle is the connection of the secondary air pump pipe. Or one of these: Ha! The next picture is a close up of the changeover solenoid with part No. I'll get some more done soon.
We offer the Genuine Mercedes manifold for many hundreds cheaper than our competitors. Hope that helps, let us know what you decide. Also look closely at the vacuum line routing diagram in front of the radiator. We carry a high-strength aluminum version that snaps right on. Red circle: vacuum out connection. They are easily bumped off kilter when installing the intake while fighting to plug in that center vaccum line under the middle vacuum element. However this may still be the problem for others.
I reckon I have a faulty check valve. Let me know what part on it is actually broken and I can see if we can replace it. The next picture is a close up of the changeover solenoid with part No. I am hoping it it a solenoid of some sort but after reading this forum I am quite concerned. Really hoping this will smooth out the engine. They are probably hoping to buy a new leather couch for the lobby. Please do report back, I'd be very interested on what your findings are.
Eventually something breaks, usually the pivot arm mentioned above. I am assuming you will need an entire new manifold, because the most likely cause of failure is that the manifold is gummed up, caused a lot of resistance on the flaps, and part of it broke. Hope my experience here helps someone else as they come across the same situation. We carry the Pierburg part direct from the manufacturer, which is the Genuine Mercedes-Benz supplier. However this may still be the problem for others. Does the 2013 glk 350 also suffer from these symptoms? They could also have some buildup on them that could use a cleaning, just a guess.
If the specification is obtained, check wiring to diesel direct injection system control unit -J248-. However, commonly the vacuum fitting is the first to go and should be inspected before replacing the manifold. A defective valve means it won't open, and therefore doesn't allow vacuum to pass, this in turn stops the changeover plunger operating, thus it is stuck in the power position short path. Inside there are a number of switching plastic valves and they do go bad. The following pictures show the operation of the changeover barrel. To get the best of both worlds, the LaFerrari cuts the intake's length in half at 6000rpm, then lengthens it again as the revs rise, before dropping it to its minimum length above 8000rpm. A longer intake manifold creates more turbulence and acts as a low-pressure supercharger of sorts, while a shorter one lets the engine ingest more air under higher loads.