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Mike, Mercedes Technician
Category: Mercedes
Satisfied Customers: 39198
Experience:  Tech Expert
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Camshaft fracturing behind timing gear on 2.3 Merc truck 2004

Customer Question

Camshaft fracturing behind timing gear on 2.3 Merc truck 2004 - any ideas please ?
Submitted: 4 years ago.
Category: Mercedes
Expert:  Mike replied 4 years ago.
Hello and Welcome -

My name isXXXXX happy to help you with this issue.

Can you first please tell me - exactly what else has been changed / fitted to the engine - ?

Too - what mileage does it have ?

Rgds, MIKE......................................
Customer: replied 4 years ago.

hi its had noting else apart from new exhaust cam ,lifters, valves all exhaust ,new timing chain

milage is 626044 kms



regards keith

tel xxxxxxxx

eastbilney coachworks

eastbilney , dereham , norfolk

Expert:  Mike replied 4 years ago.
Hello Colin-

Thank you for your reply.

Was the cam an aftermarket part or OE - ?

Too - did the original cam break - and the replacement - or?

And when did this happen last - as much as you can tell me please to give all you can.. as much insight..

Rgds, MIKE..................................
Customer: replied 4 years ago.


it staeted with head / valve overhall , rebuilt inc reset cam chain adj

then the orginal cam freactured approx 100 miles , head removed check none oe cam fitted as gen on long term back order , rebuilt run up lasted approx 20 miles same cam exactly same place of fracture

regards keith

Expert:  Mike replied 4 years ago.
Hello again Keith -

Thank you for your reply and further info.

I was asking the questions to get an overview because, the usual cause of this happening on these is a fault with the chain ( timing ) tensioner - they either seize up or "jack" causing the extra tension which snaps the cam at the weakest point - as you say.

There have been cases where non OE cams , poorly made ones have done this though -thats why I was asking - but if you have had more than one go - its more likely the timing chain tensioner problem - as per usual.

So that is going to need close inspection Keith - and I would say replacement - ideally for a genuine MB tensioner at least if not chain as well - and then go from there.

Given what you have outlined, I'm 99% sure thats what the fault is with yours.. rather than a faulty cam/s.

Best Rgds, MIKE.

Let me know if you need anything more on this at all -

Please do click on the OK rating to Excellent ratings service for me now, Thank you for that... and you can get back to me anytime if you need / wish..

Best Rgds, MIKE.

Please note, you are rating the content of my "answer" - my help to you - not the "system" which can experience delays etc which are not under my personal control -or delays caused by "time -off" which we all have on occasion - Thank you.