Ok, i'm finally going to get around to changing my m117's head gaskets.
Couple of questions really.. What should I order?

Definately:
Head gasket sets,
Intake boot thing,
New fluids,

Maybe:
Head bolts?
Valve stem seals?

All other engine related maintinance is up to date, ie chain, guides and cam oiler plastics. My engine doesnt produce blue smoke, so i'm not sure if I should do the valve stem seals.

When I had my parts car, I tried taking off the intake manifold, but the allen headed bolts refused to budge and rounded, any tips on avoiding this again?

Finally, what do I do with regards to the chain before taking the head off?

Ben

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Ben

'85 500 SEL
'85 928S2
'88 560 SEC
'90 750i

Start by marking locations of chain vs the gears at TDC..use a mark that WONT wash off.

I wouldn't spend that much time & not have a valve job & guide replacement done!

ALL of the idle balance rubber hoses to the injector insulators & anything rubber & plastic should be replaced.

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What would a machine shop charge for a valve job and a head resurface?

This car is my daily beater, so I dont want to go over the top with it. It runs great apart from it using water.

Do I zip tie the chain to the cam sprocket and remove the sprocket from the camshaft?

__________________
Ben

'85 500 SEL
'85 928S2
'88 560 SEC
'90 750i

Expect to pay 250-350 a head for machining. I agree, to have the heads off and Not so the guides is a false economy.

There are also 8 large seal rings on the intake plenum. Plan on doing those as well as what was mentioned above.

I'd also pick up some industrial grade paint stripper..it will do a good job cleaning out the intake manifolds of all the built up carbon.

I'd also block off the air injection passages while you are @ it. they have a habbit of clogging/making a mess over time so I typically block them off and remove the air pump.

Jonathan

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Around this area $500-$600 for valves & guides.

Spending 20 hrs & not at least having them inspected would be a big waste of time!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Well, i'm planning on having the heads resurfaced anyway, so i'll ask them to look at the valves and guides when I take them in.
The whole car only cost me £80 ($150 or so) and i've been using it for 2 years, so it doesn't owe me anything.
One one hand, i'd just like it up an running on the cheap, but the engineer in me wants it all done right.

Edit:
Should have said, the car is a euro, so doesnt have air injection.

__________________
Ben

'85 500 SEL
'85 928S2
'88 560 SEC
'90 750i

IIRC the sprocket won't go through the head. I don't know if there is a risk of the chain slipping off an unseen sprocket. What I did ages ago is use a third hand to keep tension on the chain while lifting the head then use the third hand to pull the chain under the head when the head was several inches above the block.

How about new exhaust manifold nuts? I believe they use deformed copper nuts that don't hold so well the second time around.

Do you have the offset hex bit that lets you get to the head bolts blocked by the cam?

http://www.shoptoolsshoptools.com/shopexd.asp?id=2912

Sixto
93 300SD

Are the nuts M8? I have a box of locking copper M8's, otherwise i'd have to order them too. I dont have an allen socket thats like that, but my short (1")allen socket seemed to fit ok when I retorqued the head bolts not too long ago.

So I have to break the chain on each sprocket and wire the ends for a helper to hold onto?
Is there a position on the crank where the pistons are all in such a fasion that the camshafts are free to rotate without valve to piston interferance? IIRC on my Porsche V8 its 45'.

__________________
Ben

'85 500 SEL
'85 928S2
'88 560 SEC
'90 750i

Don't break the chain, just slip it off the sprocket after you remove the tensioner.

IIRC there is no non-interference position of the cam.

Sixto
93 300SD