johnnr

In your pic...I see you mention oil build up on the valve cover, etc.

isn't that just normal carbon build up? From my experience, this doesn't indicate an oil leak...I've seen this build up on all engines I've worked on.

Just curious cause I have some build up on my CLK, but I don't believe there are any leaks.

Rudeney

You are correct, the build-up has nothing to do with leaks, but it should nonetheless be cleaned when replacing the gaskets. Especially the ports for the oil ventilation breathers.

StevenHaywood

Looks to me like the majority of that oil leak in the OP is seepage from the PCV chambers. Worth stripping those off and checking the tiny (1.5mm!!!!) hole isn't choked up. What a crap design!Also, +1 to no gasket sealant on the valve gasket - only on the vent chambers.

PewterGreyBenz

I am getting ready to do this, so that smaller valve like cover on top of the valve covers are called breather covers?

Just want to be sure as I will pick up parts tomorrow from my local dealership

Also the one tube that you need to disconnect on the drivers side rear top of the valve cover, what is it called? It is sort of a hard plastic and wraps around towards the rear of the engine (black) Im afraid if i twist it, i will break it or should i just replace it? Thanks

Rudeney

That tube probably will break. There are actually two - one on each side. I'd go ahead and buy new ones. They are called "ventilation hoses"

A1120180382
A1120180182

There maybe a third one (on the driver's side). The dealer parts counter can look them up for you. If they have a hard time finding the parts diagram in EPC< tell them to look under "Engine" -> "Intake and Exhast Manifolds".

Eojj

Getting ready to do my valve covers and spark plugs! This is an awesome guide.. I'll be buying all the stuff for my mechanic to do this. Got a few questions:

1. Should I put anti seize on the spark plugs? What is a good brand to buy?
2. What kind of Gasket sealant should I buy for the small/breather covers?
3. Are there any safe products to clean the valve covers with?

Rudeney

There is a "factory" part for the breather cover sealant, but it's basically black RTV. As for cleaning the covers, especially where you remove the old sealant on the breather covers, there is also a factory part for cleaning that, but again, it's just RTV solvent available at most auto parts stores. I used Gunk Engine Cleaner to clean up the grease. Microfiber cloths work great to remove any oil residue after soaking them in cleaner.

tw2

I don't. It will change the torque required which can cause over tightening and breaking things. I had no trouble removing what looked like the original spark plugs after 80,000 miles.
I cleaned all the sealant by hand, I didn't know there were solvents available It took ages!

Eojj

I guess something generic like this would work?
http://www.autozone.com/autozone/acc...er=554295_0_0_

I'm guessing it's fine to use, but is there any major issues if some of the gunk engine degreaser gets into the cylinder head? Or perhaps I should just use some good ol gasoline lol


Haha if I had the knowledge and time to do this job myself, I'd take my sweet time to make sure everything was squeaky clean. I'm buying all the materials for my mechanic to do it. That means his time is $$ .. In other words, if I buy him all the correct stuff he'll get it done more efficiently. Or he'll probably just use brake cleaner to clean the stuff lol

tw2

The odd drop of degreaser is not an issue. Having sealant get in there and potentially clogging up oil drains or the filter needs to be avoided.

Rudeney

^ +1

You'll be cleaning the covers off the car, so there really shouldn't be much of a chance to have degreaser around the engine. And that is why I suggested a final clean-up with a microfiber cloth - those do a great job of removing residual oils. I buy bags of microfiber cloths from Costco. I wash them first, then use pristine cloths the remove wax, then after that, they become "shop towels".

clkcadet

Nice write up- How do I tell if its time for new spark plugs?

I have 105k, but no mention of new spark plugs in my service paperwork.

Rudeney

Got to MBUSA.COM, and click "Owners". You can find your car's maintenance manual there and the spark plug change interval will be listed in it. I believe on your car, it's every 91K miles or 5 years, whichever comes first.

M-Rods

Since torque was mentioned....what is the torque specs for the sparks plugs?

Rudeney

On the M113 engine, it's 25Nm

M-Rods

Perfect, plugs are on next months list.

Wodeshed

Right side of my CLK 320 at 145k miles:

Rudeney

Looks pretty good! It's hard to tell from the photo, but if Mobil 1 0w40 was always used, everything should be a nice golden color.

Wodeshed

Thanks for the feedback. I can't speak to what was always used, since I've been a quickie oil change place guy until discovering this forum. I always had them use synthetic, but who knows what it was. Now that I'm back to DIY, I'm doing all Mobil 1 0w-40. At least it doesn't look all crudded up like that one I saw earlier on this thread.

Just finished valve cover & breather gasket on the right (passenger) side. Also replaced plugs (with Bosch Iridium, which were the same price as the platinum) and wires.

Elsewhere here I saw the post about cleaning the tiny hole through the breather cover leading to the right side breather hose. I used a wire on that since it was partially blocked, and also replaced that hose. No P0400 code yet, so maybe that was the solution.

Right side plugs were pretty rough. Most likely original equipment, and overdue for a change.

Wodeshed

Right side plugs at 145k miles:

Wodeshed

Oh, one more observation; my oil fill neck would NOT pop off as suggested in the original post. I had to undo the passenger's side valve cover with the neck in place, then loosen the philips head screw on the interior side to remove.

phoung

I thought that sealant is not needed since there is a gasket in place. On pelicanparts, they did not use a sealant.

kennywong1234

Hi Rudeney, may you please clarify, do we need any sealant while we reinstalling back the valve cover?

From the original post, it shown he put the sealant all around lol

Please kindly advice, thanks!

tw2

The gaskets seal the valve covers. Sealant seals the breather covers. You can't do one without the other.

kennywong1234

I got it! thanks!