When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey all. I recently decided to tackle my 2003 S600 misfires and I also decided to go ahead and do the valve cover gaskets as well to completely eliminate any source of misfires from oil contamination. Since there was no guide on how to remove the valve covers anywhere on the planet, I went in all alone on this one and came across multiple problems. I also have a lot of questions on how to properly go about these repairs, so I would really appreciate any help, tips, or other input you guys may have.
First of all, taking off those valve covers were a huge pita. Removing the coil packs and intercoolers to get to it was a walk in the park. The valve cover unbolted quite easily but the rearmost part of it did not want to budge at all. At first I thought there was another bolt holding it from the back or something else was holding it down, but turns out the rocker arm all the way in the back of the engine was preventing it from sliding out due to its tall profile and there was NO ROOM to lift the valve cover upwards and slide it out due to the stupid intercooler hardlines above it and the fragile vacuum lines all around it. I had to remove them (also a major pita) and spilled coolant everywhere and only then I barely got enough clearance to pull the valve cover up and out with barely any wiggle room. As I was taking the valve covers out, I broke pretty much every single miserable dried out vacuum line there was.
I thought to myself "no worries, just some cheap and easy to find vacuum lines" right? Wrong. I wasn't able to find these parts anywhere, and I would be most comfortable just replacing them with brand new oem lines rather than fitting aftermarket ones. The vacuum lines in question all stem from these two cylindrical valve things on the passenger side of the engine. Any help or guidance with these vacuum tubes would be greatly, greatly appreciated. Thank you.
And to make matters worse, I noticed some sludge on my cams. I don't think this valve cover has ever come off and this is the first time I'm seeing this. What should I do? Should I leave it alone? I'm tempted to get a Q-tip and clean all the sludge out carefully.
Now, on to the coil packs. As you can see here, these coil tubes look very distressed, but they were still working when I got them out the car. Only misfired when boost kicked in. I feel like I can save them by spraying some deoxidizer on the corroded tubes and spring contacts, then giving everything including the oily red boots a nice wash with soap and water. Is there anything else I should do to save these packs? Also, should I put dielectric grease on the red boots when reinstalling the coil packs? My spark plugs were changed two years and 10k miles ago, so I'm assuming they are still fine and will keep them in the car.
Lastly for now, I really need to know the screw pattern/tightening sequence and torque spec for the valve cover bolts. I don't want to change the gaskets only to have them leak again and go through all this crap all over again. It would be greatly appreciated. In addition, if there is anything else I should do as a "while you're in there" thing, please let me know. Thank you for everyone's time and help.
Thank you so much for that diagram and pictures, it really helped me a lot, I appreciate it. I'm assuming I need to buy a few of item 220 (the plastic vacuum tubes) and connect them with item 100 (the rubber hoses that connects them). Do you also have the tightening sequence for the valve cover bolts? I PM'd you my email.
I can agree with the fact that any rubber or plastic in that engine compartment at this age turns into peanut brittle. Along with breaking the vacuum lines I broke pretty much every pcv pipe and plastic connector. I'm sure I can just reuse the connectors without the plastic covering around them, unless that's a bad idea. Also, I was wondering if I should replace the camshaft position sensors as a while you're in there thing, unless its unnecessary and a waste of money.
I was thinking of using something more robust than the stock MB vacuum lines, but I think they should be good for another 100k miles like these ones lasted. Plus its a cheap and safe option.
FYI: on my NA V12 I too had trouble getting the left (drivers side) valve cover off. You have to remove the rear cam shaft sensor before (it can interfere with the rocker in certain positions).
Since you've got the line diagram, that answers that question.
The next question: re-use the ignition coils? If you can get clean contact surfaces, OK. The tube is an insulator, and doesn't really matter, but the coil spring inside that contacts the plug does matter and I don't see how you'll get that clean. You had a misfire when you undertook this job, so, I would be prepared to have Clark Rupp rebuild your coils if the misfire is still there once you've got it back together. New coils run about $1500 retail (my dealer will work with me on price, but they're still about $1200) and Clark charges $700, I think. They should've been replaced with the plugs, so they shouldn't be old, but I would use all new insulators (the red boots).
The other question: sludge. Looks like the engine had a skipped oil change in the past. You've got some varnish (discoloration, thin coat) as well. As a comparison point, my valve covers came off at about 85,000 miles and were pristine inside. So, I would clean what sludge you can with a q-tip. Don't use chemicals, detergents, or flushes. Just change the oil with a good quality (I like Mobil 1 0W40, and have several good Used Oil Analyses to support that choice) synthetic and cut the change interval in half for a few changes. Keep using the Mercedes OEM "Fleece" filter. Clean it slowly with the detergents already in the oil and it will slowly get better.
I changed the plugs along with both coils exactly two years ago and the car was running like a dream until a couple months ago when it started misfiring again. The insulators are pliable and are not cracked. I'm going to try and restore the coils before I bite the bullet and get new ones. I'm going to be using this
which I've used before on corroded electronics and it worked like a charm. Nobody has done this before, and it won't hurt to try it out. The coil packs still work, it's just that all that corrosion and oil acts as resistance and makes the coils work harder, inefficient, and intermittent which results in misfires under load due to extra pressure that the corroded springs covered in oil just can't push through. This is all theoretical, but once I get all the parts I ordered and get back to working on the car we'll see for ourselves. Also, I don't know if I should use dielectric grease when reinstalling the coils.
As for the sludge and varnish, I have been using Mobil 1 0W40 for the past 4 years I've had the car and have been changing my oil every 5k miles. I've been using the OEM filter too. I remember when I first got the car, I did an oil change and it looked like sludge was pouring out of the engine. I can easily tell this car was abused by its prior owners, and 4 years under my care apparently wasn't enough to clean all the sludge.
06-01-2018, 04:51 AM
