Timing Chain Jumped?

[joe]

I thought I would share my story. I had my 53 plate w203 180 k serviced last week (18/12/2008 A Service) On christmas eve at 7pm it refused to start. I called Mobilolife and they arranged for local breakdown to attend. About 40 mins later a tow truck arrived and car was transported to my home.
This morning I called them again and 1 hour later a mobilolife technician arrived to my home and spent about 2 hours working on car.
He has decided it may be that the Timing chain has jumped. The car has just been transported to local dealers. I am waiting for the hire car to arrive.
I am absolutely delighted with the Mobilolife response and service.:bannana:
I am sad that a car that has full service history and just 50,000 miles could have a problem with timing chain. I am thinking if his diagnosis is correct it is very likely that my engine will have serious damage.

I will wait until next week when dealers will have chance to investigate it, and report

Once again, Great Service from Mobilolife.

Joe

 

[grober]

This from the Mercedes C CLASS entry on the Honest John site:- 2000 - 2003 4 cylinder petrol engines have an actuator that alters the cam timing to one of two positions This actuator is hydraulically operated and triggered by a solenoid. The solenoid coil has part of the wiring loom attached to it by a plug. An oil seal fails at the plugs connection with the solenoid coil allowing oil to slowly flow onto the plug. Oil finds its way by capillary action between the copper wire and plastic sheath of the loom, and migrates two plus metres along it until it reaches the cars ECU damaging it. This would of course also affect an auto gearbox if fitted. A safeguard is available in the form of a short 150mm loom extension with plug and socket. This stops the capillary action. Spare part numbers that make up this pro-active unit are (a) 1110510177 cost £30.00 (b) 1119970186 cost £1.69 and (c) 2711502733, cost £16.90. If the oil gets to the ECU the cost of repair is around £1,400 incl VAT.
I mention this because a timing chain "jumping" at your car's mileage is unusual unless the tensioner/ chain follower has failed. A failure like that would have probabaly been accompanied some mechanical noise pre failure?

 

[joe]

It seems Mobilo life technician was correct and the Timing chain had jumped.
On new Years eve I collected the car, They had fitted a new chain and Tensioner.
Total cost £550.
Service manager mentioned he had a very similar car/same prob a few days earlier with similar mileage to mine.
So I am thinking I am fortunate not to have extensive Engine damage, but sad such a component can fail at 50k miles.

Regards
Joe

 

[BlackC55]

That is a VERY unusual falt.

Thanks for reporting back.

 

[merc180k]

Reading this and now wondering when the timing chain should be changed. Is there a particular mileage it is advisable at?

 

[Smiley]

I am just interested to know how and why a timing chain can jump one tooth; never heard of this before.
I wonder if there was a simpler fault that has been rectified but the OP has been billed for a new chain. (£550 sounds cheap for that job at MB dealer?)

 

[joe]

I am just interested to know how and why a timing chain can jump one tooth; never heard of this before.
I wonder if there was a simpler fault that has been rectified but the OP has been billed for a new chain. (£550 sounds cheap for that job at MB dealer?)

Well, Most of the Bill was Labour, @ a reduced rate because of my complaining about Chain failing.
When the Car was taken to the dealers I had asked about the "Oil in the Harness" and the results appearing like cam chain had jumped. I also expressed my doubts over a Duplex chain "Jumping"
The Manager said this would be checked.
I am also baffled by this fault, The Car was operating perfectly until I returned after stopping at a shop and trying to start it.
I heard no noises.
All in all, for the service I received over the Christmas period, I was pleased with end result, But still mystified.

Joe

 

[c240yaz]

Timing chain jumped on my Avenger Tiger back in the late seventies, after strip down, suspect was rubber tensioner breaking up.

Also bent several inlet and exhaust valves, dented pistons, broke duplex chain, timing chain cover, ripped a gash through tin sump, crank and cam sprockets teeth and valve spring retaining collets were launched and dented the tin rocker cover ! The sump was full of shrapnel.

I was doing about 70-80 MPH at the time, so the drive momentum was still turning the crank.

Complete block and head overhaul. Luckily, me and the mates took great pleasure on the labour, so no cost there. However, this did give us the excuse to rebuild with stage 3 head and mess about with the performance with alternate cams like Kent and Piper !!

I hope this cannot happen on a V6 Mercedes !

 

[Dieselman]

Probably the tensioner failed so let the chain go slack and jump when the starter motor was used.
Starting is the most common time for chain or belt failure.

 

[jaymanek]

the thing that grober mentions often fails on the 4 cyl engines... it starts off ratting and replacing it is an expensive chain off job... And yes the electrical connection lets oil past causing all sorts of issues. The fix is a lenght of extension that basically bungs the oil.... - german bodgery at its best..

 

[grober]

This incident is interesting because it causes me to ask the following question:-

For owners whose car develops a fault under warranty and is repaired free of charge by the dealer- presumably paid for by MB UK? - What paperwork does the owner receive concerning this repair? Is it the normal itemised bill listing labour and parts and consumables etc or is it a brief summary such as cylinder head gasket replaced under warranty? Never having been in the position to receive this - my cars are usually too old - would be interested to know. A fully documented repair would also be useful to the owner/buyer as a record of work done once the car leaves the official MB service arena.

 

[jaymanek]

owner gets a full breadown but its shown as charges at zero... so all the parts and labour hours are listed...I get a fair few of these...

 

[Autofix]

This is actually a very common issue. I have seen it happen at as little as 39k. On sat morn I was doing a job for a Merc specialist who had 3 with the same fault.
The timing chain is only single, not duplex, and stretches. Jumping a tooth often happens after a service.

The honest john info above applies to the earlier engine and the chain issue is on the later one.

 

[Dieselman]

Single chain...there's progress for you..
I'm not sure whether I prefer good thick belts to chains anyway, especially now they are using necklaces again.

 

[grober]

Back To The Future????

Interesting indeed -it would appear all the Lanchester shaft engines have single chains the one for the cams and the one for the balancer shafts--- maybe not enough room for 2 duplex chains in the timing case? http://www.detali.ru/cat/oem_mb2.as...605716.628&CT=M&cat=63A&SID=05&SGR=045&SGN=02 Obviously does nothing for the reliability - MB appear to have reverted back to the technology of the 1980's where lots of their engines had single timing chain problems. Pity.

 

[joe]

Part numbers are
MA000 993 21 76 ROLLER CHAIN £91.50
MA271 050 04 11 CHAIN TIGHTENER £44.20
MA000 997 62 20 EXPANSION PLUG £1.20

 

[zerocool]

I seem to remember a technical bulletin about these engines,where the plastic guide between the two cam sprockets breaks up,and causing the chain to become loose and possibly jump,

 

[grober]

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