OT - progress with my W140 (its using time and money that could go on the W116)

Started by s class, 16 August 2006, 05:27 AM

s class

Sorry guys - Heretic post alert. 

Since January I've been using a 1992 500SEL W140 as daily transport.  Thought It may amuse some to see what a traumatic experience this has been :

* overhaul supension/power steering tandem pump : US$150
* overhaul power steering box : US$300
* return the (butchered) Becker 1432 audio system to factory spec : US$100
* repaired closing assist pump (automagically closes the doors) : free once I figured out what was wrong
* repaired trunk pup-out handle (extends when trunk is open) : free once I figured out what was wrong
* replaced fuel filler vacuum unit : US$15 second hand
* replaced drag link : US$150
* replaced idler arm bush : US$75
* replaced steering damper : US$85
* replaced gear shift assembly : US$60 second hand
* overhauled aircon pump : US$100
* replaced aircon condenser and drier : US$400
* engine service and transmission service : US$250 for oils and filters
* replaced thermostat : US$50
* replaced upper chain guides : US$20
* replaced tappet cover gaskets and sump lower pan gasket : US$150
* replaced fuel filter : US$40
* replaced spark plugs : US$15
* replaced both distributor rotors and both caps : US$200
* replaced ignition leads  : US$60 second hand
* Mercedes diagnostics at an "independent" " US$50 - this was done today in an effort to solve my persistent misfire.  Result is new coils :
* new coils (both) : US$350 (I pick them up today - lets hope it fixes the trouble)

What this list excudes is hours and hours of reading and headscratching and knuckle-skinning.

Prices above are approx, and are for the spares only, or the out-work in the case of pump overhauls.  I remove the pumps myself and send them in.  Otherwise I've done everytihng myself (and stuffed up a few things in the meantime)

Ryan - (enjoy your simple, reliable, beautiful W116)

[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL


Hello S-Class,
It sounds like your having lots of fun, anyway learning lots of new tricks. GOOD LUCK
Regards Robert
116   1978 450SEL 6.9 #  4848
116   1979 450SEL  6.9 # 5884
116   1979 450SEL  6.9 # 6225  SOLD
116   1978 450SEL  6.9 # 5128  SOLD
116   1979 450SEL  6.9 # 5884  SOLD
116   1974 450SEL  DJet

s class

W116 S class Enthusiast,

Many of those items were bought from Autohausaz.  W140 parts are a LOT more expensive than regular W116 (I can't comment on 6.9).  Things like rotors and caps are OK to buy mail-order because they are not too heavy.  Things like drag links are just too heavy to have mailed. 

I used to be able to buy here from an "alternative" Bosch, Bistein, Meyle, Lemforder etc agent, but they now no longer are willing to supply to private people, you have to be a registered motor repair concern.  So I had to buy my drag link, steering damper, idler arm kit from the agents at about 80% more than the "alternative" supplier.  I have now found a registered garage that is willing to oder these parts from the alternative agent on my behalf, but he adds like 30% handling fee.  That's how I got my coils for only(!) US$ 350. 

[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

Brian, Styria,

The W140 is like a VERY VERY guilty pleasure for me.  it is sooo very expensive to maintain, but it is just SOOO good to drive.  In fact my wife asked me if it was better than, well, you guess, and I actually think it might be  :P

Here's now an AMAZING story of the latest misadventure with the car.  I've discovered that the right rear wheel had a positive camber (the lower end of the tyre is more inwards than the top).  After much debate with the alignment people I decided to replace the hub carrier assembly.  This has many knuckles that connect to the various arms of the multilink suspension.  I carefully micro'ed all the angles and offsets of my hub and compared it to a new one and found this was not true.  I then replaced the bushing between the lower control arm and the hub carrier.  Actually its more like a bearing of sorts - with a thick metal outer skin and a ball joint assembly inside.  THe old one had collapsed.  I paid about US$50 for this work of engineering art, and spent about 4 hours last night to press it into place.  I went this morning again for an alignment check - guess what - NO IMPROVEMENT!

Then we started measuring things and found that the lower control arm on the offending side is about 10mm (!) shorter than the other side and in fact it's a different shape!.  Seems some PO must have replaced it with an item from a W210 or a W129, I'm not sure, that is visually very similar but just not the same dimensions.  I just cannot believe it!.  I suppose anything is possible with the PO.

On the W140 one often doesn't notice these things at first because EVERYTHING (even suspension arms) are all hidden behind plastic covers which can conceal a multitude of sins. 

But I'm excited because at least I know what's wrong!

[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL

s class

Still trying to track down the misfiring, in october I removed the upper and lower halves of the inlet manifold, skimmed everything and reassembled with new gaskets, O-rings, seals, pipes etc.  I found that a number of the rubber seal rings between the upper and lower halves were leaking, causing alots of vacuum problems, and more significantly, false air bypassing the mass air flow meter (MAF).  These seal rings are rubber elements the same as the M117 uses. 

This all helped.  I then spent about AUS$200 replacing all the rubber breather tubes, tee-pieces etc.  There are many of them, some related to EGR, and all were problematic. 

I also had the LH fuel injectors refurbished, and refitted them and the fuel rail with all new genunine (read : crazy price) seals.  I have measured and confirmed the fuel rail pressure is correct at all times, and fuel delivery is fine.  So the pump and pressure regulator are OK.   I used a tektronix TDS3034B (very pricey - borrowed from work) digital scope to verify that the fuel injector signals are correct at all times. 

Car was better by the end of October, but still not right.  I borrowed a ETA (electroic throttle actuator) and MAF from the scrapyard and wasted many many hours playing with them  (the ETA is very very fiddly and timeconsuming to fit and remove.)

Conclusion : I ordered another ETA from Mercedes - it recently arrived from germany, for the princely sum of about ZAR8000  - or about AUS$ 1600.  I have been too busy at work to get to it.  Just before I took the car off the road to deal with that I have brake problems - sudden terrible fade, like master cylinder problems - no external fluid leaks. 

I decided to sort out the entire system and I have genuine mercedes seal kits waiting at home for all 4 calipers now (this weekend's job).  Plus new pads all round.  Convinced my problems were due to the master cylinder, I removed it (terrible job - it required about 3 hours to get it out including removal of the ABS piping, and lots of ducting etc just to get to it. 

I then discovered that my car is one of a batch of W140's that use a special triple bore master cyliner with internal valves and safety features, that cannot be overhauled.  After 3 weeks of on and off looking into this problem, I have confirmed that I cannot obtain a seal kit for it, and in anycase I cannot get all the 3 pistons out of it.  The only option appeared to be a new complete cylinder from Mercedes,. for which they want over AUS$1500.  Feeling gutted I decided to take it for professional help, and they confidently said that they couldnt do much to help me.  I left the bits with them to play with.  This morning they phoned to say that they reassmebled it, and bench tested it and guess what?  Its perfect, with no fade or leakage.  OK I had been sure that was my problem, but I guess we can all learn.  So, the good news is the master cylinder is OK, the bad news is now I don't know what IS the problem.  Leakage in the ABS system?  So this weekend hopefully I will get the master cylinder and calipers back in, and bleed thoroughly and take it from there.  I have also bought all new flexible brake pipes. 

If thay goes well and I have any change out of my Sunday, I must remove the tappet covers and assess the chain stretch.  I am sure it needs replacing.  I have this week got myself a decent dial gauge to asisst with determing of the valves are opening at the correct crankshaft angle.  I will also remove the chain tensioner and inspect. 

styria, hoe will I know if I need a new tensioner?  If its stuck, OK i'll replace.  If it is operating smoothly, can I happily reuse it?  Its a similar type to what the M116 and M117 use. 


[color=blue]'76 6.9 Euro[/color], [color=red]'78 6.9 AMG[/color], '80 280SE, [color=brown]'74 350SE[/color], [color=black]'82 500SEL euro full hydro, '83 500SEL euro full hydro [/color], '81 500SL