Valve cover gasket replacement.

[Boudreaux]

I purchased valve cover gaskets for my SL500 and wanted to replace them this past weekened. However, I removed the top nine (9) hex screws for the right side cover and gently tried to loosen it and it won't move. Are there some other hidden screws that are holding it down? I don't want to force the cover off and break it since I've already spend $3k in repairs and don't want any unwanted expenses.

[MikeTangas]

Your car is a little new for my experience, but I have to ask - what size were these hex screws?

Judging from both of my somewhat older V-8s, there should only be four 10mm bolts holding the valve cover down. You didn't by chance pull the head bolts, did you?

Again, Not sure if things changed that much since '86, but 9 bolts along the top fo the valve cover seems somewhat excessive.

[Boudreaux]

Hi again,

Sorry, I miscounted the bolts (should be 7 vice 9) 5 mm hex screws. Should I used a rubber mallet to loosen the cover?

[rsmcmahon]

Remove air cleaner.
Model 210: remove cover over intake manifold.
Detach crankcase ventilation lines (4) and (5).
Engine 119.960: detach vacuum line at crankcase ventilation line (4).
Engine 119.960/97:unbolt engine wiring harness (19) at right cylinder head cover (6a).
Unbolt vacuum line (16) of brake servo unit at intake manifold.
Unclip, then remove covers (1) and (1a) over high voltage distributors.
Open fuel filler cap and release pressure.
Engine 119.960: disconnect fuel lines at pressure regulator and fuel distributor.
Engine 119.97/98: disconnect fuel pipes (17) and (18) at fuel rail. Use box wrench 000 589 68 03 00.
Take off shaft covers (14) and (14a) over spark plug cables and ignition coils.
Engine 119.96/97: unplug spark plug connectors.
Engine 119.98: unscrew and remove ignition coils,
Engine 119.985 in Model 210: unbolt windscreen washer fluid reservoir. Swing to the side with lines connected so that left cylinder head cover can be removed and installed.
Remove bolts of cylinder head covers with seals (10). Pay attention to different lengths of bolts (see bolt diagram).
Take off cylinder head covers (6) and (6a) with gaskets (7) and (7a) and shaft seals (8).
Installation
Reverse Procedure to install, noting the following:


Replace all gaskets together, ensure crankcase ventilation syphon at left cylinder head cover is correctly located in the drain hole.
Model 210: ensure the fuel pipes are correctly routed; fuel pipes must not be touching cylinder head cover and engine cover.

[rsmcmahon]

dont' for these bolts

[rsmcmahon]

under the cover.

[Boudreaux]

Thanks for your help. Judging by your photo, I had overlooked a few bolts for the valve cover as well as the fuel pipe removal. I had removed the bolts and laid them on a towel that corresponded to their locations on the cover because I noticed that they were of different sizes.