M104 Valve cover and upper timing cover replacement

[Parshman]

Just replaced the valve cover seal, front timing cover gasket, and O2 sensor. The job really isn't that bad and I have steps for the M104 engine now if anyone wants them, or has questions about replacing the timing cover. Also the valves were unreal clean, which makes sense for the amount of miles my car has. I have pics on my phone if anyone is interested in getting them. This was lots of fun.

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[myfirstbenz]

Looks clean in there! Boy, the fun job with that motor is adjusting the cams to make sure that they are in sync properly... I don't ever want to run into that problem again.

[Parshman]

I'm glad I didn't have to adjust anything because I didn't do anything with the cams or timing belt.

[loubapache]

That is really clean. What oil do you use and how many miles and oil change interval?

[Parshman]

Originally Posted by loubapache

That is really clean. What oil do you use and how many miles and oil change interval?

I use valvoline 5w30 6.5 quarts. at intervals of 3500max and the engine has 56K miles on it. I'm selling the car though, but this shows that the engine was taken care of. I aquired it at 51000k miles.

[loubapache]

That just shows what a short OCI can do wonders to engines.

If you do not mind, I would like your procedures. I have a 97 E320 and the upper timing cover has a leak. I have seen other writeups but it seems to be very involved. I wonder if you have a shortcut.

Thanks,

[Parshman]

Originally Posted by loubapache

That just shows what a short OCI can do wonders to engines.

If you do not mind, I would like your procedures. I have a 97 E320 and the upper timing cover has a leak. I have seen other writeups but it seems to be very involved. I wonder if you have a shortcut.

Thanks,

Now are you sure the upper timing cover is leaking? because the funny thing was that mine wasn't. it was leaking from the TDC sensor because there was no O ring. If you would like you can call me and I can walk you through the step because there is two steps you should do to make everything easier. My phone number is 410-279-3149

[loubapache]

Thanks Parshman. I also got your PM.

I am sure it is the upper cover. The leak is at the lowest point of the upper cover and that is where the lower cover gasket terminates. I have wo 300E's and both leak at the exact sme point. The M104 upper cover was re-sealed at 48k miles and it started leaking at 60k miles.

I am not going to do it now because it leaks a ouple drops per night on the garage floor (with a diaper). I was just ask to see if you have written the procedures down. In the other procedures I read, the coolant has to be draind because of the water pipe in front of the cover and belt tensioner removed.

Thanks again.

[Parshman]

Originally Posted by loubapache

Thanks Parshman. I also got your PM.

I am sure it is the upper cover. The leak is at the lowest point of the upper cover and that is where the lower cover gasket terminates. I have wo 300E's and both leak at the exact sme point. The M104 upper cover was re-sealed at 48k miles and it started leaking at 60k miles.

I am not going to do it now because it leaks a ouple drops per night on the garage floor (with a diaper). I was just ask to see if you have written the procedures down. In the other procedures I read, the coolant has to be draind because of the water pipe in front of the cover and belt tensioner removed.

Thanks again.

The coolant does not have to be drained, there is a pulley that is removed which allows the lower left bolt to be removed. you first remove the valve cover. then you remove the rotor( make sure you have a #30 torque very important) then you remove the plastic lower cover. remove the tdc sensor . Then you remove the small pulley between the center of the engine and alternator. remove the hex head bolt holding down the metal water pipe in front of the engine. This give you total access to the cover. The really tricky part is removal of the sealant material. Make sure to put sealant all along the edges. its just a bunch of bolts to remove.

[loubapache]

Do you have the early M104 (rotor and caps?). The m y 1997 versionis a bit different (coil).

[Parshman]

yeah its the m104.980 engine
similar engines m104.981 3.2L

[Payson]

So what was the trick for having the engine inside such as clean?
I saw other M104 opened like that one and had the camshafts all in a yellowish color due to the oil.

Thanks
Payson

[Parshman]

well it helps that the engine only has 56,700 miles on it. Also doing oil changes every 3500 miles or less(3500 is max miles).

[Payson]

Originally Posted by Parshman

well it helps that the engine only has 56,700 miles on it. Also doing oil changes every 3500 miles or less(3500 is max miles).

Wow, you really care about your car´s health. Changing oil every 3500 miles is almost maniac xD.
I also have an M104 engine, the 320, I would like to ask you if u have any idle issues, i recently changed silemblocks and have better idling but not perect, it stills have a RPM hesitation while idling. I use Mobil 1 5W50 is it a good oil for this engine??

Thanks a lot
Payson

[Parshman]

I use 5w30 , what do they list in your manual to use? I had a slight idle issue too and when I took the cap off the rotor I saw wear and just wirebrushed it away and the idling issue went away. That might be where your problem is. how many miles on your car and have you ever cleaned the cap?

[Payson]

Sorry but my english is not as good as I wish, im spanish and I dont understand what the rotor cap is. If you could kindly attach a pic or explain it to me with more detail I might get a clue xDD.

Thanks for all
Payson

[Parshman]

Originally Posted by Payson

Sorry but my english is not as good as I wish, im spanish and I dont understand what the rotor cap is. If you could kindly attach a pic or explain it to me with more detail I might get a clue xDD.

Thanks for all
Payson

Its the orange cap where the spark plug wires plug into, its attached to the front of the engine

[soundquest]

Originally Posted by Parshman

Just replaced the valve cover seal, front timing cover gasket, and O2 sensor. The job really isn't that bad and I have steps for the M104 engine now if anyone wants them, or has questions about replacing the timing cover. Also the valves were unreal clean, which makes sense for the amount of miles my car has. I have pics on my phone if anyone is interested in getting them.
This was lots of fun.

Wow, you can eat off of that! Cleaner than clean in there! My 95 E320 has 174K on it and it is almost just as clean in there except I have the very common yellow tint but it is not varnish or sludge, just a microfine depth of staining on the metal itself. These engines run incredibly clean and I believe one of the reasons is that they engines were designed to heat the oil evenly without any cold spots or hot spots, just even throughout. Toyota had a real problem with engine oil sludging with many of their engines from mid 90's to around 2005 because they overlooked this. The only other engine I have seen that runs clean like these (with regular oil changes) is my 94 Saab 900 turbo.

[Chinny4290]

you guys use light oil.


I use 15W40.

[soundquest]

Originally Posted by Chinny4290

you guys use light oil.


I use 15W40.

I personally think it is a mistake to run anything other than 15W40 in these engines. Go ask a veteran Mercedes Tech and he will tell you the same. I run a 5W-40 Synpower in my Saab 900 however, but that's a 4 cylinder turbocharged engine - doesn't drip a single drop after 167K.

[jl772009]

Originally Posted by Parshman

Just replaced the valve cover seal, front timing cover gasket, and O2 sensor. The job really isn't that bad and I have steps for the M104 engine now if anyone wants them, or has questions about replacing the timing cover. Also the valves were unreal clean, which makes sense for the amount of miles my car has. I have pics on my phone if anyone is interested in getting them.
This was lots of fun.

I would like to have those steps if you would be so kind sir! It's an $800 job if I take it to my mechanic.

[rick dean]

1993 300e 2.8, could someone email me some pictures and steps on how to replace the timing cover gasket? Send them to barbershop@mchsi.com

Thanks a bunch.

[pjcoop1]

Parshman, and other Senoir Members,

M104 Valve cover and upper timing cover replacement

I have just purchsed a 1989 300CE that appears to have the infamous timing chain cover gasket leak or may need a head gasket. Of course I am hoping for the former and would greatly appreciate any "insider" tips on replacement. I have ordered the shop manual on CD and hope to start the project in about 2 weeks. Also, any special tools that are an absolute must have to add to my box? any/all help , suggestions welcomed

Next phase if I do not have to replace the head gasket and rebuild the cylider head would be to tighten up the steering, control arms or something , there is about 2" play left to right when driving straight

[bingbong]

Originally Posted by jl772009

I would like to have those steps if you would be so kind sir! It's an $800 job if I take it to my mechanic.

Yeah, me too, I need to replace the seal on my timing cover (M104 E320 1994). Thanks a bunch.

[ddilillo]

I wanted to post a pointer on replacing the front timing cover gasket. The green U shaped gasket is really easy to roll while you try to put the cover on. (I know it happened to me twice!) I came up with the idea of putting a very thin strong piece of cellophane with oil on both sides on top of the green seal prior to putting the cover on. This keeps the green Gasket from rolling on you. After you have the cover in place prior to tightening it you can pull the cellophane out. I recommend at this time to take a small mirror and inspect the gasket to ensure it is on properly.

I took my piece of plastic from the inside of a binder that I was using on a weekend retreat. The silence helped me to brainstorm the solution. Dean