New member.with a very sick w140.

[kenny]

Hello everybody.
i am a new member i have owned a w140 420,for 4years
it as never let me down,till now was sat on motorway in traffic come to set off just creeping off then no power car just stopped,got it on hard shoulder,was gobsmacked,
got it recovered home ,loads of phone calls later,still no wiser,my son came over took rocker cover off,timing chain loose,loads of calls again,av been told the timing chain tensioner is famous for breaking up is that rite,
have been told engine will be ruined,been told it will not as bad as you think,i do not know what to do,can it be fixed,thanks in advance,kenny

 

[panason1c]

Dont want to be a doom-monger but a 'stopped' engine because of a loose or broken timing chain would suggest to me an end result of bent valves.......hope i'm wrong!

 

[grober]

Depends what happened when the timing chain broke? You may have just got away with it. Unlikely the bottom end of the engine will affected. Some valves may be bent, cams damaged. Best probably to whip the heads off to check all the valves/ timing gear are OK. You will have to replace all front timing chain gear of course. What to do depends on the mileage/state of the engine (and the complete car) before this happened. Ball park figure of the top of my head assuming the bottom end is OK =£1000ish ? Lot less if you DIY of course.

 

[MBManInKen]

That's the scenario that put an end to the life of my V140 S500. Timing chain broke, resulting in massive damage. Car beyond economic repair.

These are interference engines and chances are pretty high that it has been damaged beyond reasonable repair.

Maybe worth getting a second opinion, I had the car examined by an independent to confirm the diagnosis by the Mercedes garage it was towed to. But I would not hold up my hopes of repair if it indeed has been a broken chain.

Out of curiosity, how many miles did you have on it? And did you ever get the chain replaces or checked?

 

[kenny]

hi there,
it as 69700 miles,is in lovely condition everything works as it should,David taylor The body shop in Bradford has looked after it since the day i got it he thinks it is a lovely car,av changed oil and filters regular,I have had it 4 years and only done 20,000mile in it thought it was going to run forever,it will be going into the body shop in bradford as soon as david as got space for it,
dronsfield av offered me 500quid for it dont think so.
thanks for replying.

 

[Howard]

I'd get a quote for it , and take it from there ...

If you really like the car , and it's low mileage ( which it is ) then it might be worth doing it ... as not much else will have worn out in 70k miles ...

Also , it's better the devil you know , you could scrap it and get another one, but who knows what history that will have had ...

Sorry to hear of your problems

H

 

[grober]

From what you say its deffo worth repairing if the engine bottom end has survived. If the chain came off at low revs and the pistons aren't holed or the bore scored then its worth an engine rebuild IMHO. Good luck --sounds as if you have a decent guy in the trade who will advise you since he will know the car.

 

[MBManInKen]

I don't want to sound negative, but is the mileage verified? It does not only sound low, it is a very low mileage to have timing chain problems.

I got quotes for my S500, but even with Mercedes offering half price labour rates, it would have come to a lot more than the car's remaining value to have fitted a new engine.

But as I said, make sure you get a second opinion to properly assess the damage.

 

[kenny]

hello there.
every body who see,s the car always remark on the mileage,av got all the mots all the mileage carries on ,i drive a truck for a living,the car only did 70 mile round trip to work and back once a week,biggest mileage it did in one go is to the airport and back,
cant wait to get it in the garage to strip down.will keep you posted its been good reading the advice from everyone,it will get sorted ,or will buy another one,
dont want to drive anything else,
its my 3rd merc luv em.

 

[Will]

Nothing else to add really, I feel sorry for you - that's bad luck at such a low mileage IMHO

I think from the sounds of things, it deserves a repair or replacement engine, the rest of the car should keep giving for many years yet

Will

 

[Howard]

Kenny ,

Where are you based ? Try our very own Ian Walker at 124works in Preston if it's in range for you . I'm sure he'd be willing to have a gander at it.

Good luck mate, sounds a nice car.

H

 

[Ian B Walker]

If you are very lucky the cam might have snapped. I hope it did for a number of reasons. Mainly, if it did then you may get away with two or four bent valves. Its an interference engine, meaning that the valves, if constantly open, will hit the pistons when they travel upwards. It is quite possible that the piston crowns could be just scored (as mine were on an E220), same engine configuration cam wise. Now the bad news. Your cylinder bores are alusil treated, meaning that to replace the treatment will be very very expensive, if you can find someone to undertake the task. My advice would be to find a replacement engine and have that fitted. Naturally you will need a guarantee with whatever you wish to do.

 

[teemyob]

waiting

hello there.
every body who see,s the car always remark on the mileage,av got all the mots all the mileage carries on ,i drive a truck for a living,the car only did 70 mile round trip to work and back once a week,biggest mileage it did in one go is to the airport and back,
cant wait to get it in the garage to strip down.will keep you posted its been good reading the advice from everyone,it will get sorted ,or will buy another one,
dont want to drive anything else,
its my 3rd merc luv em.

Still waiting, what was the result?

 

[Will]

This thread is five years old..

 

[teemyob]

This thread is five years old..

And 5 years on, no update±

 

[Rashman]

Must have ended badly

 

[Will]

And 5 years on, no update±

OP only posted three times on this single thread five years ago, and hasn't been online for four years now.

If you're genuinely expecting an update you might be in for a long wait

Why not post a new thread if you're looking for advice, much more likely to get a response

 

[grober]

The 4.2 M119 V8 valve train is reputed to more vulnerable than the M119 5.0 engine. Seems strange since they are basically the same engine design. Perhaps the cam lobe profile is a little more aggressive in the 4.2 and this puts a bit more strain on the valve gear??