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I read it has to do with the PCV valve. Do you have any codes? CEL? symptoms? https://mbworld.org/forums/w211-amg/...-m156-e63.html
I'd say it's easier to DIY than other platforms as we have more space between the firewall and the engine.
Good luck and keep us updated.
Well I have replaced the PCV valve of the rear of the engine and I am pleased to say, on the ML, it’s not as bad as others seem to have it with the M156 engine in other chassis.
Mine is also fitted with an LPG Conversion so I had even more stuff in the way and so taking off the inlet manifold would have been more involved. I will keep the LPG stuff out of this write up as it wont be relevant to many out there.
I started by removing both air intakes and the front engine cover to gain access. Then its time to get cosy with the engine. Then covered the engine with some stiff cardboard and a lump of foam to get comfortable on.
You have to lay right over the engine, not just lean over it.
Its fairly easy to get to the T27 torx bolt that holds the valve to the back of the cylinder head and remove it. A small ¼ drive ratchet, a 2 inch extension with the torx bit is all you need.
Once the bolt is removed, I gave the plastic pipe a wiggle and it snapped where it had become brittle with time. This was good as it gave me a little more room down there. A further wiggle and I was able to snap the pipe again for even more space.
Looking over the back of the engine down towards the bell housing of the gear box, you cant see the PCV valve connection at all, you can only feel it.
I put the car up in the air on the ramp and from underneath you cant see it either. You cant reach up past the cats to feel it from underneath either, which from on top looked possible.
With the car back down it was time to get cosy with the engine once again but this time with an old door mirror glass.
Now I had a good view of it. With the mirror balanced on the top of the gearbox bell housing and the bulkhead I decided to use a flat blade screwdriver to get to the retaining clip.
This is the tricky bit, you are looking down on it, in a mirror, so everything is in reverse and upside down.
Eventually I managed to get the blade of the screwdriver into the retaining ring quite deep. Then with a twist of the screwdriver and a little prying I was able to snap it.
Once it was snapped, a little pull and twist of the plastic at an angle and it all come free.
A final inspection with the mirror showed all was well and no debris was left. A quick check of the cylinder head part where it bolts to was also completed and all was good.
The new valve goes into place easily with just the small amount of threading around to get it under a silver tube / pipe that is slightly in the way.
With the lower clip o connector loosely in place but not clicked on fully, I got the top bolt on part on place and with the torx bold stared and 90% tight before clipping the lower connector on fully. This locks home with a nice firm clunk.
A final tighten of the top torx bolt and all was good.
A refit of all the air intake and connectors was soon done in reverse order and I was good to go.
Without the LPG stuff in the way, doing a second one on this chassis with the extra room is an hours work maximum, all from on top and without the intake manifold having to come off.
Hope this helps someone else out there.
I have also included other photos I found on the web for ease to show the lower connector. It’s strong and tuff where it meets the block so don’t be scared of giving the plastic hose some stick when removing it if needed. I would be surprised if you were able to damage the metal fitting even if you tried.
Good job, excellent write-up! Thanks a lot mate. I'm going to replace the valve soon. These are the symptoms:
1- Engine idles higher than normal.
2- Oil dipstick popping out after spirited driving.
3- Whining/whistling noise close to the firewall.
4- Current and stored 3699-P0191 code that won't clear.
Fortunately our cars do have bigger space behind the IM compared to the other platforms.
What year is your ML? What is the part number for the valve?
The reason I'm asking is according to EPC all engines up to serial 60000591 should use part# A1560100270. My car is a 2007 ML, engine serial number is 60000528.
Hi, mine is an 2007 also but with an engine serial of 60004723 so I used A1560100370.
Not sure what the difference between the two valves will be.
With only engine serial numbers below 591 (so only the first 591 in the world) you may find that the part you need is no longer available when you go to order it and it supersedes to the other part number.
Looks like this DIY will be in my future...Just picked an ML63 and the dipstick keeps popping out just enough to allow oil to splatter all over the engine. GREAT!
Does anyone know the part number for the newly revised dipstick?
Thanks
Last edited by IceScraper; 11-30-2018 at 09:40 PM.
Looks like this DIY will be in my future...Just picked an ML63 and the dipstick keeps popping out just enough to allow oil to splatter all over the engine. GREAT!
Does anyone know the part number for the newly revised dipstick?
I actually got lucky this time and only had to replace the O-ring at the end of my dipstick. My mechanic is awesome and said the pressure valve is fine and that this engine is just noisy. I've had this ML only a week so am I just getting used it to myself.
I just went thru replacing my PCV valve. I looked all over the forum at various guides, but somehow missed this thread with Badygoods post! I wish I would have seen the tip about using the mirror. It was honestly one of the hardest jobs I've done taking me over 2 days to remove and install the new PCV valve. I cut up my fingers using a razor trying to cut that clip all by feel not being able to see anything. Its extremely uncomfortable having to lay inside the engine and maneuver. Somehow I got it installed though! Since having the car a little over 6 months I noticed the whine like a super charger when accelerating hard. I always thought it was part of the engine. After doing some research I got lead to replacing the PCV. Now whenever I would drive hard the dipstick would pop out, and I noticed the car would idle different and more quite when I put the dipstick back in. I took it for a drive yesterday after replacing and the car felt very smooth however after pushing it again, when I checked the dipstick came out again. I ended up ordering the revised one, it seems like mine barely stays in there, even barely touching it and it can come out. So I don't see how it would stay in with the pressure of acceleration. Hoping the new dipstick helps my issue.
I just went thru replacing my PCV valve. I looked all over the forum at various guides, but somehow missed this thread with Badygoods post! I wish I would have seen the tip about using the mirror. It was honestly one of the hardest jobs I've done taking me over 2 days to remove and install the new PCV valve. I cut up my fingers using a razor trying to cut that clip all by feel not being able to see anything. Its extremely uncomfortable having to lay inside the engine and maneuver. Somehow I got it installed though! Since having the car a little over 6 months I noticed the whine like a super charger when accelerating hard. I always thought it was part of the engine. After doing some research I got lead to replacing the PCV. Now whenever I would drive hard the dipstick would pop out, and I noticed the car would idle different and more quite when I put the dipstick back in. I took it for a drive yesterday after replacing and the car felt very smooth however after pushing it again, when I checked the dipstick came out again. I ended up ordering the revised one, it seems like mine barely stays in there, even barely touching it and it can come out. So I don't see how it would stay in with the pressure of acceleration. Hoping the new dipstick helps my issue.
Yes, the updated dipstick wraps around the metal tube and holds stronger.
Edit: Forgot to update, I changed my PCV valve and drove it and still had the same problem. I changed the dipstick and it no longer pops out and I don't have the supercharge noise anymore, the car performs really good now.
Edit: Forgot to update, I changed my PCV valve and drove it and still had the same problem. I changed the dipstick and it no longer pops out and I don't have the supercharge noise anymore, the car performs really good now.
I changed out the dipstick, doesn't pop out so that's cool. I think it runs better but I don't know. Still need to change pcv and power steering res. I still have a whine at high rpm and an oil leak. I think it's the oil pressure check valve but I need to take the front end off to make sure. Might do the dremel fix if I don't need to take the whole front belt assembly off for some other reason. Also will be doing engine mounts, maybe headers and exhaust, and suspension work. It's a little clunky and sways alot. Could be the ****ty tires the last owner put on.
I changed out the dipstick, doesn't pop out so that's cool. I think it runs better but I don't know. Still need to change pcv and power steering res. I still have a whine at high rpm and an oil leak. I think it's the oil pressure check valve but I need to take the front end off to make sure. Might do the dremel fix if I don't need to take the whole front belt assembly off for some other reason. Also will be doing engine mounts, maybe headers and exhaust, and suspension work. It's a little clunky and sways alot. Could be the ****ty tires the last owner put on.
Don't wait on the power steering resoivoir like me, I ended up losing my entire pump while I was dirving and had to have it towed to a shop, it was very costly. PCV is going to be a huge pain if you are doing it without removing manifold. Just try taking one thing at a time if you have a number of issues. I'm going to probably tackle new suspension shocks next for my car when the weather gets warmer. Tires can definately help, I've been happy with my continentals.
Don't wait on the power steering resoivoir like me, I ended up losing my entire pump while I was dirving and had to have it towed to a shop, it was very costly. PCV is going to be a huge pain if you are doing it without removing manifold. Just try taking one thing at a time if you have a number of issues. I'm going to probably tackle new suspension shocks next for my car when the weather gets warmer. Tires can definately help, I've been happy with my continentals.
Did the power steering res the other day. Soooo much better. Actually have a silent pump now. I went heavy on the flush just incase the wrong fluid was used. Plus fcp sent me way too much fluid so I figured might as well. Next weekend is the oil filter housing o.ring, engine flush and oil change with ceramic stuff added, and hopefully the pcv. I have small hands and plenty of tools and extensions. Plus theres a cool guide some guy did on here showing how to do with without removing the intake using a mirror to see the hard to reach areas. I'm confident I can get it done. Then I just need to slap in new fuel injectors one day and also take care of the cam adjusters before they get worse. Then hopefully the engine will be good for a while and I can take care of the suspension work before next winter.
Did the power steering res the other day. Soooo much better. Actually have a silent pump now. I went heavy on the flush just incase the wrong fluid was used. Plus fcp sent me way too much fluid so I figured might as well. Next weekend is the oil filter housing o.ring, engine flush and oil change with ceramic stuff added, and hopefully the pcv. I have small hands and plenty of tools and extensions. Plus theres a cool guide some guy did on here showing how to do with without removing the intake using a mirror to see the hard to reach areas. I'm confident I can get it done. Then I just need to slap in new fuel injectors one day and also take care of the cam adjusters before they get worse. Then hopefully the engine will be good for a while and I can take care of the suspension work before next winter.
I didn't really have a good mirror for the PCV so I did it entirely by feel. I've worked on alot of things on cars and it was one of the most frustrating things because of the angle and trying to cut that pipe without being able to see anything. I got so bruised and cut up trying to lay down in the engine bay in various positions. I have pretty thing hands too. I plan to do more maintenance on the car once my new garage is finished being built. I enclosed my garage last year so I've had to work on everything on the car outside in a driveway which is tough. Keep us updated how it goes.
So now I have another problem with the update dipstick, its too short! I can't get a good reading off it, and I threw out my old one. So I'm going to have to buy the old dipstick again to get a good reading for when I check the oil.
03-10-2017, 05:39 PM
