Snapped timing chain - SLK 230K

[vijilants]

Suggest you have a look in ebay aswell....I recently saw a couple of C230K's being broken.

I think this guy had one ......www.slpagoda.com. 07899 801373.

Sorry to hear about what has happened.....I myself drive a c230k and usually these engines are by far one of the strongest and are undertuned for what they are.

Very strange - must have been some sort of a flaw in the chain or something may have gone wrong with the tensioner.

 

[nick mercedes]

Hiya

I was pulling off a roundabout so was probably only travelling at about 25/30 mph

Deborah

Expect 4 bent valves.

Best outcome 4 bent valves, new chain.

Worst end new valves, chain and gears.

 

[c240yaz]

No timing chain will last forever. The tensioner will always wear out eventually, leading to lesser tension on the chain, wear on the peaks of the crank and cam sprokets, then the chain jumps the cogs, knocks the timing out instantaneously, which bends the valves,.... then the chain breaks.

As soon as the chain jumps, all damage is done instantly. In less than a second.

Worse case scenario, Chain, sprockets, tensioner, several valves, valve guides, seals, camshaft, cam bearings, casing, pistons and possible cylinder head.

Anytime that I have repaired similar in the past, when you drop the sump and you will usually find shrapnel from the above damage.

 

[Will]

I'm thinking, 2 options:

Strip engine down to assess damage. In best possible scenario (and conservative estimates) find a few bent valves as Nick says. Approximate cost to repair -

Labour to strip down and inspect - £200
min 4 new valves (~£100) + fitting/face or check head (£100)
new chain + new gaskets etc - at least another £100

Refitting - another £200/300. I'd say that was keen price-wise and a bit of a skimp, if I was having that work done, I'd want a new tensioner at least, probably guides, maybe sprockets if they're worn/damaged in any way. Another few hundred there. Total cost would be around £800-1000 all in this route. Still a 105K mile engine which has suffered an unusual failure, bit of a gamble to how well the job will go. If it's damaged something else - ie more valves, bottom end, damage to head etc then it'll be either ridiculously expensive or scrap.


2nd hand engine, probably with less than 105K miles too = maybe £500 or so, fitting costs, maybe £300. That's say, £800, even if it cost £1000 all in if you had to pay a bit more for an engine, still not an expensive route, although you might be lucky and find one cheaper - there's quite a few around in breakers/ebay etc these days.

Both methods will cost similar amounts although I do think that as these engines are normally so reliable it'll be a better devil that you don't know in this case (mileage/problems considered).

If you pay to have the head removed and it's beyond economical repair, it's more good money after bad. That's what would swing it for me.

Will

 

[Howard]

If you put a new engine in it , would it matter that the engine number wouldn't tally up with the chassis number ?

 

[Will]

Nope.

Not on a 100K mile 10 year old SLK! You just inform DVLA and have it changed. Mind you, who ever checks their engine number against the V5 these days.

Will

 

[television]

These things as said can break, anything can break, we had a con rod that just snapped near the little end. The chain did not have to be noisy before it snapped, maybe a sprocket or camshaft broke, till it is taken down no one will ever know for sure

 

[c240yaz]

These things as said can break, anything can break, we had a con rod that just snapped near the little end. The chain did not have to be noisy before it snapped, maybe a sprocket or camshaft broke, till it is taken down no one will ever know for sure

Agree. If a replacement engine is available at a breakers, this is the route that I would take for economy and speedy repair.

 

[television]

Agree. If a replacement engine is available at a breakers, this is the route that I would take for economy and speedy repair.

Oh yes I agree too. very much so as there are few good engineers left

The old engine could be a nice little project for someone to do on the kitchen table like we used to

 

[bolide]

There's been lots of good sense talked in this thread

One thing I would add that may help your decision: the cost of repairing what's there is an unknown and is likely to rise during the process of repair, whereas the cost of a replacement engine plus fitting should be pretty much fixed at the outset

This factor alone may help you decide which way to go

Nick Froome
www.w124.co.uk

 

[Deborah]

As an observation, 105k miles is pretty high for an SLK (but obviously the same engine reaches that sort of mileage in saloons much more often).

The amount of damage would surely be based on engine RPM rather than vehicle speed. Presumably there would be a high chance of piston damage, possibly even conrods. With cheap labour a repair/rebuild might be feasible, but at garage rates a replacement engine would surely be the cheapest option.

Hi Bill!!

Yes I'm thinking that a second-hand engine is probably a better solution in the long run. The garage may find that a lot more damage has been done and then I've wasted money. Another thought that someone else had was that I trade it in, as is, for another Merc with a dealer who will be able to fix it a lot cheaper than me!!!

It's a difficult decision .........

Deborah

 

[kth286]

Deborah

Have you seen the broken timing chain.???????????

It may just be the cam/s end gear that has snapped off !!!!!!!!!!!

I would want to see the problem with my own eyes.

Which garage is the car with ???????????

 

[television]

Deborah

Have you seen the broken timing chain.???????????

It may just be the cam/s end gear that has snapped off !!!!!!!!!!!

I would want to see the problem with my own eyes.

Which garage is the car with ???????????

You think like me Kieth, it does not take much effort to take the cover off and have a look, does it

 

[Deborah]

If the car has FULL MB service history then ask if they will offer you any compensation.
The timing chain broke on my Dad's first merc years ago. After a bit of discussion, MB agreed to supply a new engine but we had to pay the labour (about 1k at the time I think)

I believe someone else on here also had the timing chain break on his (I think) S Class. He got a discount on his next purchase.

So it's worth pushing them on this as timing chain's are not supposed to break. That's why Merc fit them. And it's one of the (few) reasons why I buy mercs.

It does have a full MB service history. I am in "discussion" with the MB that serviced it last but am getting nowhere!! They have suggested a MB re-con engine at £3k with a possible £1k back for mine ....... ooooouch!

 

[Deborah]

There was a strange "ticking" noise after I'd had it serviced in July but didn't worry about it too much because MB had just had it!!!!

It has had no other work carried out ......

 

[Deborah]

Suggest you have a look in ebay aswell....I recently saw a couple of C230K's being broken.

I think this guy had one ......www.slpagoda.com. 07899 801373.

Sorry to hear about what has happened.....I myself drive a c230k and usually these engines are by far one of the strongest and are undertuned for what they are.

Very strange - must have been some sort of a flaw in the chain or something may have gone wrong with the tensioner.

Nothing on e-bay at the moment but thanks for the link. The MB garage said the tensioner may have worn down but until the head is off apparently you can't see anything and that'll cost me about 6 hours labour!!!

 

[Deborah]

Deborah

Have you seen the broken timing chain.???????????

It may just be the cam/s end gear that has snapped off !!!!!!!!!!!

I would want to see the problem with my own eyes.

Which garage is the car with ???????????

Hiya!

No I haven't - apparently you can't see anything until the head is off and that will cost me 6 hours labour which may be a complete waste if the engine is completely wrecked!

 

[Deborah]

No timing chain will last forever. The tensioner will always wear out eventually, leading to lesser tension on the chain, wear on the peaks of the crank and cam sprokets, then the chain jumps the cogs, knocks the timing out instantaneously, which bends the valves,.... then the chain breaks.

As soon as the chain jumps, all damage is done instantly. In less than a second.

Worse case scenario, Chain, sprockets, tensioner, several valves, valve guides, seals, camshaft, cam bearings, casing, pistons and possible cylinder head.

Anytime that I have repaired similar in the past, when you drop the sump and you will usually find shrapnel from the above damage.

Gawd!!!

 

[jaymanek]

this is the first time i have heard of a timing chain snapping on a merc with this mileage... I would get someone trustworthy to look at it.. how far are you from Ian Walker or Olly?

 

[Deborah]

I'm thinking, 2 options:

Strip engine down to assess damage. In best possible scenario (and conservative estimates) find a few bent valves as Nick says. Approximate cost to repair -

Labour to strip down and inspect - £200
min 4 new valves (~£100) + fitting/face or check head (£100)
new chain + new gaskets etc - at least another £100

Refitting - another £200/300. I'd say that was keen price-wise and a bit of a skimp, if I was having that work done, I'd want a new tensioner at least, probably guides, maybe sprockets if they're worn/damaged in any way. Another few hundred there. Total cost would be around £800-1000 all in this route. Still a 105K mile engine which has suffered an unusual failure, bit of a gamble to how well the job will go. If it's damaged something else - ie more valves, bottom end, damage to head etc then it'll be either ridiculously expensive or scrap.


2nd hand engine, probably with less than 105K miles too = maybe £500 or so, fitting costs, maybe £300. That's say, £800, even if it cost £1000 all in if you had to pay a bit more for an engine, still not an expensive route, although you might be lucky and find one cheaper - there's quite a few around in breakers/ebay etc these days.

Both methods will cost similar amounts although I do think that as these engines are normally so reliable it'll be a better devil that you don't know in this case (mileage/problems considered).

If you pay to have the head removed and it's beyond economical repair, it's more good money after bad. That's what would swing it for me.

Will

I know, I know!!! That's why it's such a mine field. If the car were younger then the economics of all this may make more sense. I'm guessing that a second-hand engine with fewer miles will be a better option than opening Pandora's box!!!

Having said that most engines I've found aren't complete so I'll have to pay for bits to removed from my engine and put on the "new" one e.g alternator, wiring loom which racks up the cost again ........ !!!