tensioners torque specs was 9Nm, front cover was 5Nm and you have to replace bolts because they become very brittle but you can get away with it by tightening them very careful.

 

How did you not install it correctly? Seems when you tighten the filter cover it would correctly push the filter down so it clicks.

You sure it was this which lead to loss of oil pressure?

 

He may of fitted an after market filter, the type that doesn't have the extension at the bottom with the little oil ring.

 

Hi I know this is an old thread but I want to remove both secondary tensioners and fit the uprated ones. Can you explain what position the the timing marks should be in for both heads. I know the bottom pully marks should be at 40 deg ATDC for the right hand head with the timing marks pointing down and inwards but I can't find any info for the other side. Also I'm a bit apprehensive to undo the tensioner bolts as there is a lot of pressure on the tensioner. Is this normal.
Thanks in advance.

 

I believe it’s either 360 degrees to the next 40 degrees mark, or the manual says 53 degrees. When you take off the tensioner take the bolt closest to the plunger out 1st it will be fine if you are in the right spot, I’m doing the job right now.

 

I just read this entire thread, thanks to all who have pioneered this problem. I will need to tackle this with my 2012 E350 as it has the dreaded start up rattle and just started with a check engine light related to the camshafts. Only 84,000 miles seems far too young to have engine failure on a Mercedes engine. What happened to quality? Oh well, I will be turning all the wrenches myself. Previously I repaired my 2007 E350 which needed the balance shaft replaced and all timing components so I am not new to engine repairs. At least it sounds like the 2012 can be repaired inside the car. I had to pull the engine on the 2007 to fix it, with the engine pulled both heads had to come off to replace the timing guides and chains. That was a hard job, I hope the 2012 is easier.
FYI: i saw where one owner pulled his chain tensioner but did not install the check valve because it was already in there. Check Valves can fail, they are not perfect, if you are in there replace them even if the factory had installed them. I would hate to do this job twice.

One question, the 2007 engine used a very special Silicone to seal the valve covers, oil pan and front cover. I don't remember the brand name but it was hard to find and expensive but worked. Is this same silicone needed for the 2012 engine or will standard RTV work?
Due to other things going on this job will have to wait a few weeks before I tackle it. This will allow me to acquire all the needed tools and parts hopefully.
The cam adjuster at $700 each, wow, hope those are still good. If I read correctly if the snap while rotating the engine they are shot? I have yet to determine which side driver or pass is causing my noise.
Thanks
Mark

 

the RTV is Renzo, I’ve used rtv black and been fine. Yes if the cam adjuster pops when the engine is turned by hand, it is bad. Getting out the old check valves, is damn near impossible, but I have done it.

 

Assuming you had all four adjusters:

1. To do it right, is this an engine out job?
2. About how many hours is this job? I saw 8 hours above but that was for 1 adjuster.
3. If I went to an indy, how much would I be out of pocket all in all?

 

I have not had time to even start work on my E350. I did do a lot of reading and it sounds like all 4 adjusters could be changed with the engine in the car but also I believe it is usually just one adjuster that needs repair? I hope to get on this job in the next week or two and will report what I find on tear down. Hoping to pull the front cover, maybe valve covers and find a broken tensioner, then check the adjusters by rotating the engine and listening for the click sound of a broken adjuster? That is my plan and hoping for a simple repair. Have not started the engine in a month, I do not want additional damage. Engine only has 84,000 miles.

 

All parts arrived and I started the repair today. Bummer, right at the start I find I don't have the Oil Filter Tool needed to remove the Mercedes Oil Filter. I ordered one but it will delay me a couple days. I removed the cam cover, driver side or left bank. Rotating the engine by hand the Intake Cam Adjuster snaps with each full revolution so I am pretty confident this is my problem. My Cam Cover has the Blue bolt heads so I think that means it has received the Mercedes updated Cam Tensioner and oil check valve but I will not know till I remove the oil filter and gain some room to see. I plan to try and snake the new cam adjuster in without removing the valve cover. I figure this is a 50/50 chance to get it correct, if it does not work I will pull the valve cover. FYI: I did rotate the engine by hand before removing the cam cover and I could hear the cam adjuster snap at the same point in rotation each time. It is faint with the cover on but loud with the cover off. Because I heard the noise I had already ordered the parts. Wish I had known about the 14 point oil filter housing tool needed. I will report back if this method works or fails. Due to oil on the cam gears/adjusters and chain I am having a hard time marking them with paint so I know the exact location for the new adjuster install. I keep cleaning best I can and the paint won't adhere. I guess I will hit it with brake clean and try again before removing the parts. Harmonic balancer is set at 40* for the cam adjuster removal. Mark

 

Well, Failure, I should have had help on hand, an extra set of hands to keep the exhaust cam from turning as I replaced the cam adjuster. It turned, I can’t turn it back so I will remove the manifold and valve cover to do this repair. My 2012 M276 did not have the Oil Check valve installed. It takes the smaller check valve not the larger stepped check valve. I was able to slip the check valve in without the press tool. So ordered more parts, intake gaskets the upper chain guide and I will pull the valve cover and set up my timing. Bummer the quick replace attempt did not work but I should have known to have help on this job. If I could have held the cam from turning as I replaced the intake adjuster the engine would be running already. Hope this helps the next guy.
EDIT: I think the reason this cam moved was my fault, I believe I was 360* out on the crankshaft. Should have verified I was on #1 compression stroke and 40* on the timing mark before removing the tensioner. rookie mistake and I know better. Remember the camshaft turns once for every two turns of the crankshaft so I was one full turn away from where I should have been to pull the tensioner and then the cam adjuster.

 

I pulled the Valve cover off the driver side or bank 2, open the hood and it is the right side as you look in from the front bumper. Getting the fuel injection lines off and unbolting the vacuum pump from the manifold took as much time as the rest of the job. With the valve cover off I was able to put the camshafts back in time and install the new cam adjuster with no trouble. Working alone again I was able to hold the cam shafts in place by connecting a Vice Grip on each cam. There is a nice location about in the middle where you can snap the vice grips on while holding the camshaft in the right place for assembly. This worked well for me. Got the adjuster installed with the timing chain on my marks pretty quick. Installed the new timing chain tensioner and new oil check valve with no problems. Pulled the pin and with a tool in place to hold the cams down with the timing cover off, I rotated the engine about 8 full rotations to set the tensioner properly, BTW the new adjuster is quiet through this process, the old one made a snapping noise with every rotation. Set the timing mark to 53* and took off the cam hold down tool. Installed the timing cover with no bolts or silicone and checked the timing marks. All 4 cams are dead center now with the timing at 53* so it is ready to assemble. I am waiting for a upper valve cover chain guide to arrive for final assembly. I bet it is 8 hours plus to put this together. The vacuum pump bolts and the High Pressure Fuel lines and brackets will take most of that time. Those bolts are a real pain. Using the vice grips in combination with a ratchet on the front cam adjuster bolt it was easy to get the cams back in sync and get the chain on in the exact spot where I made my marks on tear down. It took a few tries to get the new cam adjuster to line up perfectly on the 2 small pins at the front of the camshaft but once lined up it slipped right on with the chain in place. The trick, keep the exhaust cam turned a little tight against the chain rotating it counter clockwise till the chain is tight but still on your timing mark so the chain is exactly where it was on tear down, don't turn hard or you will rotate the crankshaft and mess everything up. IF there is play in the exhaust side chain you will not be able to install the chain tensioner on the intake side. This was easy, with the chain properly on the exhaust cam adjuster and on the marks you made on tear down just turn the exhaust cam with the front bolt till the chain is tight, no more, just till tight and you may only move it 1/4" to get it tight. Now while still holding it tight snap a Vice grip onto the exhaust cam, you can do this so once snapped on the cam can't turn and loosen that chain. Now work with the intake cam same way, snap another vice grip on that side with the chain between the two adjusters tight. Now there is plenty of chain slack in the right spot to install the new timing tensioner. With these in place and the tensioner pin pulled I went ahead and spun the crankshaft 8 full revolutions to set the tensioner. Stopping at 53* all 4 cam adjusters are in the proper timing windows dead center.

 

The Intake on this same E350 has oil in it, oil can only come from the PCV or Crankcase ventilation vent on the passenger rear side cylinder head. I ordered one so assembly is on hold till that part comes in. Of course on this model the High Pressure Pump has to come off to fix it. Dang, nothing is easy on this car. Still can't believe I am doing this to a Mercedes engine with less than 90,000 miles on it. Picking up parts yesterday at the dealership I shared this opinion with the parts man. He actually replied, "well if they lasted forever we would not sell many new cars" maybe they should remember people are buying these cars because they had a great reputation for reliability and get back to that? Nice cars no doubt but corners are being cut in expensive places to fix.

 

Engine running again, startup rattle is gone, no leaks all looks good but the intake camshaft is not in sync on bank 2, driver side intake camshaft. Scan tool shows it is at 36* constant and not adjusting at all. The other 3 cams adjust constantly with RPM changes. When I get a chance I will lift the intake once more and double check the cams to see if they are in sync at least through the cam sensor holes with the engine at 53*. If I clear the check engine code P001885 the engine starts instantly, once I shut down and restart the check engine light is on and it starts slowly, maybe 8-15 seconds crank time. Each and every start since the first start have been quiet so the cam chain rattle is fixed with the new Cam Adjuster, cam tensioner and oil check valve installed. I am close to happy. Still need to fix the cam so the code goes away. I am going to let this sit a week or two while I do another project and hopefully create a plan of attach to fix this car. Slight chance I may need a new camshaft, I find it hard to believe the timing could be off a tooth and run as well as it does so looking for a fix. Thanks
Mark

 

Westlotorn; I would say it's the positioner. My eng is very much like yours and 36 is exactly where mine would sit if the positioner wasn't working. So that suggests to me it's simply not moving. Hopefully it's something stupid like not plugged in.
If it were off a tooth I'd assume it would still adjust but unable to adjust far enough. I guess you can figure out how far off a tooth is by counting them, and know it can adjust 40 crank degrees, no doubt -4 to +36 relative to TDC, like mine. What are the odds that it jumped a tooth and ended up exactly far enough off that no adjustment takes place AND that just happens to be the resting position of 36. I'd imagine the odds are zero.
So my $ is it's correct but simply not moving.

Fyi I had that engine a couple years ago and I had to make a "catch can" for it. Make because I believe most all those sold don't work well at all, but mine caught everything last particle. So I suppose I would replace the PCV/oil separator but if that doesn't cut it I have pix and what not of the one I made.

 

Chevota, Thanks for the conversation on my timing situation. I verified the Camshaft Adjuster I installed is the correct part number for the Left Intake Camshaft. I have no way yet of knowing if it is a good part or maybe a bad part? It is a brand new Febi if I remember correctly which I believe is a German made part. Memory says it was in an OEM looking Mercedes Box when I received it. I already threw out the old part and box. Wish I had kept it. I re used the factory Cam Adjuster Bolt, any chance this Bolt is the failure part? I will pull out the cam adjuster magnet if that is the correct term, I did install a brand new part with the new Cam Adjuster/Timing sprocket. I felt really good about the timing set up before I installed the valve cover and the marks were in the correct place under the cam sensors. I have started this engine many times now including two starts with the block dead cold, morning start up and it has been totally quiet with each start. That is wonderful. I hated the chain rattle on start up. Sounded like a absolute piece of junk on start up for 5-10 seconds. Glad that is fixed. I am thinking there is a moveable part inside that Cam Adjuster bolt that is not moving, either electrical issue or mechanical, maybe the brand new adjuster magnet is not working or I received a bad Cam Actuator sprocket. Strange though I think this engine had the exact same intake stuck on 36* when I took it apart and I thought it was caused by the bad adjuster and cam tensioner. On tear down my engine did not have the Oil Check valves under the tensioner so I did install the check valve. My engine used the smaller of the two check valves, one size is just under 8mm and the other has a step at the end and is over 8mm. My Scan tool does 2 way communication with the OBD2 port but I have not yet found a way to instruct the Cam Adjuster to activate, it says this feature will not work because the Cam is out of proper range. I can read what * it is at currently but can't do anything manually. FYI: one other thing found, if I shut the engine off, turn the key to ON, clear the codes and start the engine it fires instantly, maybe one revolution and it jumps to life. In this fresh start after code clear mode the Intake Cam bank 2 driver side reads 42*, once I shut the engine off and restart it will start slow and take maybe 10 seconds of cranking before it fires, now the check engine light is ON and the cam reads 36* where it stays until the code is cleared. All 3 other cam adjusters when monitored vary constantly with RPM changes. I feel better thinking this may be fixed without another total tear down. Thanks
Mark

 

Maybe 42 is the normal position and 36 is wrong? That would make sense because the relaxed position is as far retarded as it can go, but it can't know it's fully retarded unless the eng is spinning so it must assume 42. Then once spinning it sees it's 36 and you get a code. You say the positioner is new? I suppose the pickup could be bad, but I'd think the pickup would read nothing, or if anything it would not be steady? Maybe swap pickups and see if the problem stays or moves with it. Or do you have to pull the intake to swap those?

I looked online but didn't find any data on what the oem cam range is. Maybe try to find someone with that eng that used the Torque app or similar and recorded it. I think people post data on the Torque Pro forum? Might get lucky.
I'd also suspect if the tool is saying 36 is out of spec and the other is fine, then I'd have to go with 42 is correct. I'd also assume that error is causing a delay in starting. Being off by that much will not cause a physical problem, so it's the error. Maybe it sees it isn't right and is thinking about letting you start it period, like it's double checking the # to be certain it's not worse or something, then it "allows" you to start it. Again, codes cleared, it assumes correct #'s and fires off before it realizes it's wrong.
One tooth is not 8 degrees, so back to the positioner, pickup or who knows what. Plus you said it was reading 36 before, right? If so, then it's nothing you did. I'd assume positioner but I doubt a new one and new adjuster net the same issue. I'd still consider swapping the adjuster to the other side to see what happens. Or, I suppose you could swap wires. Not so easy but they sell a kit that should have all the parts to do just that. I think the link is on this forum, "cam wire harness pigtails" maybe?
Point is you could swap and if the problem remains it's more likely the ECU, or wiring, but mix n match swapping wires and you could figure it out. I'm too tight to buy the pigtail so I'd probably just use pins to do it. Or, for all I know, the wires will each reach the other side? I think your ECU is on the side of the engine? If so, then no, but if it's in the middle, maybe, but you'd have to cut open the harness a bit. Just options for how I'd go about it, and I'm outside the box so its just optional info.

I'd also check the positioner and pickup wires for oil. Not sure about yours but my eng has an issue with oil getting from the positioner and pickup into the plug, and I'm pretty sure we share the same parts. Oil goes down the wires to the ECU and causes problems. The oil shouldn't upset the positioner or pickup, unless maybe really dirty, but once it's at the ECU it can cause issues with other things, like the O2 sensors that are sensitive, or worse; into the ECU and find a spot that is sensitive. Eg; down the exact wire to whatever reads or drives your cams and screw that up. So I would check for oil in the connector plugs, and if so, unplug the ECU to be sure no oil in that plug. If there is, I'd open the ECU, but we'll worry about that if it gets that far.
Or who knows, maybe the part in the ECU just took a dump all by itself. We can fix that as well btw.
I don't believe the bolt could cause any issue of any kind. I even re-use the one-time use aluminum bolts. If it failed you'd have much bigger problems.
If you can't find the pigtail link and want to try that, I'm pretty sure I saved the link somewhere.

 

I am tied up for a bit and can't work on the E350 right now. I keep thinking and reading and so far I do not have any information on what could be my first step for this repair. Another possible issue is the plate on the cam that the computer reads to see cam position. I understand that plate can move on some cams leaving you out of time. There are video's out there that show how to examine the cam to make sure the plate is in the correct position. Wish I had seen that before closing this engine up. Would have been a 2 minute check to verify they were correct. There is an etching on the cam and on the wheel showing if they are lined up exactly to each other. If those marks are off it means the plate has moved. Mercedes used a press fit on this part and some of them end up moving. Should have been welded when built.

 

possibly. since its not moving id assume it sees the fault and deactivates to full retard, the default safe position. if so, and correct is 42, then i guess we know how far its off.

 

Follow up, I finally was able to get back to my 2012 E350 M276 repair. I pulled the manifold again and the cam sensors. Set the timing to 53* and checked all 4 cams. 3 were good but the bank 2 intake cam was slightly off center, no way it is a tooth off but the cam sensor pulse wheel was not spot on. I know they have been known to move and people buy new cams due to this failure. My cam adjuster is new, timing tensioner is new, oil check valve installed but this wheel is off. I took a 18” flat blade screwdriver/pry tool and moved the sensor wheel on the cam till it was lined up dead center as it should be looking through the inspection sensor hole.
It moved hard, took a lot of pressure but it did move. Have to be very careful, it takes so much pressure you can move it too far easily. Once I had moved this pulse wheel into position I reassembled the engine and fired it up. Right away the computer now sees the pulse wheel and the new cam adjuster on the bank 2 driver side intake cam started adjusting as it should. Check engine light is out. Engine now starts instantly, no delayed cranking and no start up rattle.

My thinking is that the failed adjuster and loose timing chain on start up hammers on this camshaft and the vibration makes the cam wheel slip out of position??? I have not heard of any cams being out of position without also having a failed Cam Adjuster or chain rattle at start up? There is no load on the pulse wheel so I suspect my wheel will continue to work properly as long as the Cam Adjuster and chain tensioner work properly with no start up rattle. I hope I am correct this was a 2 hour fix start to finish without removing the Valve cover or front timing cover. Engine runs like a top, quiet and instant start up so it feels like it worked. If my pulse wheel had moved easily I would have gone for a new cam but it was difficult to get to move. I think it is good.

My Scan tool shows all 4 cam adjusters now working and adjusting properly, before this repair the bank 2 intake cam adjuster would not adjust and was stuck in one position. My scan tool told me the cam was out of position and could not function until proper position was achieved. I was thinking I messed up and the timing was 1 tooth off.

Update tonight: Was able to take this car on a 50 mile drive, first 25 miles were mostly uphill with several steep grades, the engine pulled really well, better for sure than before the repair. I had purchased this car broken so I never felt it run at 100%. I set the cruise control at 74 headed up the hills. It held 74 without downshifting running close to 2,000 RPM. I was impressed. Power is very good. I took it to redline twice just to see how it sounded and if that caused any issues. All Good. I think this is a good runner now, it actually sounds like a good Mercedes engine instead of the rattle trap, slow starting beast it was before. I appreciate the tips the forum offered along the way. If the pulse wheel moves on me in the future I will certainly report back. All Good for now and I am happy.

 

One week follow up, car still starting quickly, NO RATTLE! picked up a #6 misfire code. Pulled the intake manifold to check out the spark plug and coil, thinking I must have left something loose. I was surprised to find the intake gasket on #6 was split and not sealing. Leaking Air = Lean Burn = misfire. My fault of course. Thinking how this happened, I had a heck of a time getting that darn vacuum line re attached at the rear driver side by the firewall. I think I fought with hooking that up till I messed up the gasket and did no catch it on install, I remember it took about 30 minutes last time. This time to avoid this problem with a new set of gaskets. I cut a thin piece of plywood, I had some 1/8 thick stock. I cut it about 9" wide and maybe 15 inches long so it fit nicely in the intake valley covering my new gaskets to protect them. This time on install I set the manifold on the plywood, hooked up all the connections and the pain in the butt vacuum hose (maybe 5 min job this time after practice) . Once fully done I lifted the manifold carefully and slid out the plywood. The manifold is light so this was easy to do without messing up the gaskets. Holding the manifold up after pulling out the plywood I could also look and see all 6 gaskets were intact and in place before I set it down.
While in there I went ahead and pulled the cam cover off the passenger or bank 1 side and setting the crankshaft at the 40* mark, compression stroke I pulled the cam cover and timing chain tensioner so I could install the check valve. I collapsed the tensioner on my vice carefully and inserted the lock pin for install. I kept the lock pin from the new tensioner I installed on bank 2 a couple weeks back. Dang the dealer charged me $55 for the check valve when I could have bought the same Mercedes part for $32 but would have to wait a few days. I installed this check valve using a brass drift. Brass is softer than steel, I just tapped rapidly but little force and I could watch the check valve slowly slip into position till it was flush with the block ready for the tensioner install. If you hit it hard you will destroy the check valve, rapid taps using a brass drift and small hammer without much force move it slowly in with no damage. I used Fel-Pro gaskets on this install, quality seemed good and they were available at the local O'Reilly store for $30 for the manifold gasket set including both upper and lower gaskets. ( better than $10 each at the dealer )
Back together again, fired instantly and now the misfire code is gone, runs smooth. Funny how the misfire did not show up for several days of use but I can see how I damaged that gasket that failed.
Hope these notes help the next guy repair their car. The forum certainly helped me fix mine.
Mark

 

Have you fixed this issue yet? My c43 is making the same sound. If it doesn’t affect the car in the long run is it worth replacing? Considering how expensive it is.

 

One more note on my 2012 M276 repair, with the cam sensors all in time, new tensioner and check valves, new cam adjuster the engine runs like a top and has not had any Check Engine lights at all. I went in to have it smogged and it failed? I learned that the camshaft being out of sync sets what is called a Permanant Code in the car computer. These codes on all cars since 2010 only clear if the car has successfully been cold started with a full warm up cycle 15 times and driven at least 200 miles. There is no other way to clear a permanent code. So after driving it for another week and putting over 200 miles on it I went to the smog station yesterday and it passed 100%. The Permanent code law was implemented to keep people from clearing codes, doing a quick smog check and selling the car before the code came back. Makes sense but I was not aware of it prior to this. The smog shop I went to advised me to do the full cold start to full warm up at least 20 times and run it 300 miles just to make sure before testing. Avoids paying for another test just because your count and the cars count might not be the same.

 

Any chance you have the torque spec handy for that cam adjuster 'bolt' ? just installed my new right bank intake adjuster and hoping to button it all back up asap...

 

There is a torque spec, I want to say it is 96 ft pounds but you are supposed to replace the adjuster bolt per Mercedes. I marked the old bolt with paint so I knew exactly where it was seated when fully tight. On install, yes I used the old bolt, I torqued it till my marks lined up, maybe 1/32” past the old tight mark to be sure. I did this with my air impact so I did not need to hold the shaft from turning. Same technique is used when changing a pinion seal, Mark the nut in the existing position and on install return exactly to that point. Car is still running absolutely perfect.