Author Topic: M117 valve stem seals, chain guides etc  (Read 5171 times)

s class

  • W116 Addict
  • ****
  • Posts: 4,171
  • I'll keep the 116's, the rest can go
  • Location: Squeezing 3 W116's into a double garage
M117 valve stem seals, chain guides etc
« on: 06 July 2006, 07:19 AM »
OK this is slightly OT because its my 450SL, not a W116, but I'm here to ask about the M117.

a) can the valve stem seals be replaced without removing the cylinder head?

b) I want to replace the chain.  Just exactly what guides and rails are there that shoud be replaced?  Can they be replaced without completely disassembling the engine?

I believe that my engine is basically healthy, so I have no desire to upset that by removing the heads.

Thanks to any who offer assistance...

Ryan

'76 6.9 Euro, '78 6.9 AMG, '80 280SE, '74 350SE, '82 500SEL euro full hydro, '83 500SEL euro full hydro , '81 500SL

Denis

  • Classic
  • **
  • Posts: 334
  • Location: Paris
Re: M117 valve stem seals, chain guides etc
« Reply #1 on: 06 July 2006, 11:24 AM »
Hi S class and all

In theory, you are right - do not remove the heads. But when my engine's time will come, I will take the heads off.

Oil consumption through bad valve stem seals is the first source of oil consumption on these V8s (normally cared for of course). The answer to question a) is : theoretically, the heads can stay on. If the piston is at top dead center (TDC) and you actually feed a small ROPE into the spark plug hole with the objective of filling the combustion chamber so that the valve can only go down a few millimeters, you can theoretically depress the valve spring upper ring (exact name ?) down and make the two "keepers" removeable with needle nose pliers. You can then release all these parts and remove them allowing the fitment of of new valve stem seals.

Why do I say theoretically ? Because the standard way of removing valve springs on these engines entails removing the head so that a tool fits on either side of the cylinder head  >:(

You need to show the head design (or pictures of it) to a tool specialist who might tell you what tool to use to do the job WITHOUT removing the head. It may be possible to use the valve adjuster points as a leverage point to a tool that can depresse the valve with the heads in place (and the rope trick)  8)


Question B) is one I might also ask but up to now, my understanding is : replace the top rails in the cylinder heads IF they show signs of wear. But beware of a bad chain tensioner - it should be replaced (and costs much more than the chain) if your engine is no longer a youngster (under 200 000 km). My timing chain is worn but so loose that there are deep gouging marks on the underside of the valve covers ! that tensioner is NOT keeping up with the job at 311 000 Km.

Bonne chance

Denis

Paris, France

Denis

  • Classic
  • **
  • Posts: 334
  • Location: Paris
Re: M117 valve stem seals, chain guides etc
« Reply #2 on: 06 July 2006, 11:33 AM »
Quote
THAT character in old Paris!

Ahem ....vive le soccer game !!!

You are right Styria but I was suggesting the old rope trip for us poor folks that work in our driveways  ::)

Tell you my friend, my new W126 has so many improvements over the W116 ! really nice but why, oh why did they remove virtually EVERYTHING that gave an S-Class......ahh....class ?

Why does the W126 look like an overweight BMW ? why is the trunk smaller ? why is visibility looking backwards so much worse ? are these improvements  :P

Ok, me fix the W126 280SE but as a contrast maker to the fun 350SE. I know, I know, such a tiny engine but at 1,32€ per liter, my budget says NO. besides, you 6.9 owners must all drive to save gas hey ? LOL

The character in Paris


Italy, here we come !!!

alabbasi

  • Vintage
  • ***
  • Posts: 586
  • Location: Dallas, TX
Re: M117 valve stem seals, chain guides etc
« Reply #3 on: 06 July 2006, 03:41 PM »
I'm having the same problem in my 280SEL 4.5 (M117) it blows a big gush of white smoke on startup and then runs like a train. I'll have to replace the seals some day, but have no intention of removing the heads. The timing chain and tensioner were replaced less then 5000 miles ago.
With best regards

Al
Dallas, TX USA.

s class

  • W116 Addict
  • ****
  • Posts: 4,171
  • I'll keep the 116's, the rest can go
  • Location: Squeezing 3 W116's into a double garage
Re: M117 valve stem seals, chain guides etc
« Reply #4 on: 07 July 2006, 12:46 AM »
You guys have been a great help.  Denis, thanks for the very complete description of the issues around valve stem seal replacement.  I at least now feel more equipped to go shopping for tools.  Styria, thanks for your input too.

Alabassi, my symptoms are definately oil smoke on startup - heavy soke, definately not white.  I also would be inclined to associate white smoke with ATF.

I assume that replacing the tensioner is done with the alternator removed?  My intention is to replace the tensioner and chain at the same time, and preferably any guides that need changing too. 

Somewhere on this site someone posted a link (I'm too lazy to go looking for it now) to a site where I guy shows detailed pics of replacing the chain in a W108 4.5.  That was excellent.  He comments that some early engines had aluminium guides where most later engines had plastic guides.  Given that mine is a late M117, it most likely has plastic guides. 

Ryan

'76 6.9 Euro, '78 6.9 AMG, '80 280SE, '74 350SE, '82 500SEL euro full hydro, '83 500SEL euro full hydro , '81 500SL

michaeld

  • Classic
  • **
  • Posts: 433
Re: M117 valve stem seals, chain guides etc
« Reply #5 on: 07 July 2006, 01:35 PM »
I'd just like to state for the record that virtually the entire above conversation was so far over my head it was rather like looking up at a jet plane full into its flight path.  I sure am glad there are such smart folk on this forum!!!  Just wishing I was one of 'em.

(Made up) Quote: "The man walked out of the Mensa Int'l party with his head down, having finally and somewhat painfully been forced to realize that his clownish sense of humor could only take him to just so many societal circles."

oscar

  • W116 Addict
  • ****
  • Posts: 4,043
  • Location: Riverina, NSW, AUSTRALIA
Re: M117 valve stem seals, chain guides etc
« Reply #6 on: 09 July 2006, 01:53 AM »
 :D :D

Having had my valve seals replaced last december I can concur with those above that have said the head stay's on.  I don't think I had valve guides replaced contrary to what I might have said in previous posts.  I get the two mixed up.  One thing for sure is that the procedure my mechanic did was the same as what Styria said about compressed air and TDC.  Also a time consuming job but my smoke problem disappeared.

As for the timing chain, I know you know that it can be replaced with just the rocker covers removed and I had two rails replaced at the same time.  I'll have to get back to you on which ones and how much was removed off the front of the engine, if anything. 

Hi Alabbasi, white smoke ? On start-up ?

Boy that brings back memories hey Styria. You may be interested to know that I haven't had the modulator valve replaced yet.  :o I know, again, contrary to what I may have said earlier.  The better transition of gears I once reported on was probably due to the increase in power and better running following the valve gaps being set, seals replaced and new timing chain. 
Whilst in wagga last week the car went up on the hoist to look for leaks in suspension fluid.  We also checked the modulator valve  and found a slight coating of oil after the valve.  Something he's going to replace next visit but wasn't concerned with it last time. 

I get a small amount of bluish smoke on hard acceleration not long after starting and a bit of black smoke on hard acceleration at speed.  Drive it normally at normal operating temp and I don't notice anything.  It's not perfect but so much better than what it was.  The valve seals made the biggest difference re smoke and oil consumption.  I don't get any smoke on start-up like before but i can't wait to finally get the mod valve on the AT replaced.

Alabassi, from what Styria told me last year and from "what I've read", it sounds like the mod valve on your AT is kaput.  (or brake fluid which I know nuthin about).  :)
1973 350SE, my first & fave