SgtRock

I have a 2009 E350 and am approaching 100k miles. My mechanic says I will need a new timing chain and tensioner soon. I have done some research and am finding conflicting information. Some say inspect at 100k. Change at 150k, some say it depends on how well the car was maintained. Some say you never have to change it. I have keep up with my services and I am not experiencing any unusual engine noise. When should I have this work done and what should I expect to pay? Also does my engine have a single or double row timing chain?

RedGray

Summary:
Many mechanical failures very roughly have a "bathtub" like failure probability.
After some time and/or usage, the probability of failure increases.






More details:
I do not know the failure rate for the timing chain in your engine. However, it seems like it might be a common failure point.

The timing chain in my 2005 C230's engine, an M271, is a POS joke! A bicycle chain looks massive and beefy compared to the POS timing chain in an M271 engine. A number of people have had the timing chain fail between ~~70K and 100K miles. If/When the POS timing chain fails in an M271 engine, then the engine is garbage!


Which brings up a point.
Many mechanical failures very roughly have a "bathtub" like failure probability.



And one of my favorite questions.
"Do you feel lucky punk!"





In other words, some people may have had timing chain failures before 100K miles. Some people have gone over 100K miles, and haven't had any timing chain failures.

That type of failure/use is common in real life with many mechanical parts.
After some time and/or usage, the probability of failure increases.

It's up to each person to decide if the cost of preventive maintenance replacement is worth it to them, verses if the part fails in "x miles or months".

For people like me, for a cross-country trip, *I* will take the reliability of my 30+ year old Mustang with ~200K miles verses your car or any car/vehicle (new or used), because of the preventive maintenance I do on the car.
I, and many other people, know very well the likely failure points and the reliability for the parts for my Fox Mustang.


Fwiw, *I* am replacing the timing chain in my C230's M271 engine every 50K miles. I'm also using a real MB timing chain bought directly from a dealer. Yes, I know that IWIS makes the timing chain for MB. The MB timing chain from MB even has an IWIS-marked packet for the link. From the IWIS and MB-original timing chains I bought, they do look to be the same. And, I have a decent amount of professional experience looking at mechanical parts and tolerances.
However, even if the timing chains where made on the same exact machinery, by the same exact people, that does not mean that the timing chains are "equal". See the NASA document for more information on part testing/verification procedures by the manufactures. The MB part might go through additional test and/or have more samples tested. Or, it might not. Considering the cost difference (~$150), and the consequences of a timing chain failure (imho - a worthless trashed engine), *I* am not willing to take that chance.

So, when picking replacement parts for your engine/car, once again, ....








Below are a number of reference links:


Mechanical Failure Mechanisms and Reliability
March 2, 2013
Reliability Curves
http://www.opsalacarte.com/reliabili...d-reliability/
Mechanical failure can occur at any point in a product life cycle. These can be divided into infant mortality, constant failure rate, and wear out.



Mechanical Failure of Materials - Springer.com
pdf format
www.springer.com/cda/content/document/cda_downloaddocument/9789814560375-c2.pdf?SGWID=0-0-45-1433632-p175459859



Note: Imho, below is a very good thesis paper that goes over a lot of the issues involved in producing a reliable product:
Scale-up of a High-Technology Manufacturing Startup:
Improving Product Reliability Through Systematic Failure Analysis and Accelerated Life Testing by All Shabbir
Submitted to the Department of Mechanical Engineering in partial fulfillment of the requirements for the degree of
Master of Engineering in Manufacturing at the
Massachusetts Institute of Technology - September 2015
(Note: New Valence Robotics is a 3D Printer manufacturing startup founded by four MIT students.)
https://dspace.mit.edu/bitstream/han...856068-MIT.pdf



Assessing Product Reliability - Information Technology Laboratory
pdf format
www.itl.nist.gov/div898/handbook/toolaids/pff/apr.pdf


Reliability Training - NASA Technical Reports Server (NTRS)
pdf format
https://ntrs.nasa.gov/archive/nasa/c...9920023212.pdf


Characteristics of the Weibull Distribution - weibull.com
http://www.weibull.com/hotwire/issue14/relbasics14.htm


Univ of Mass - Weibull Handout
pdf format
http://www.ecs.umass.edu/mie/faculty...%20handout.pdf


Drexel University
Department of Mechanical Engineering & Mechanics
ENGINEERING RELIABILITY and FAILURE MODELS
MEM361 Lecture3
pdf format
http://www.pages.drexel.edu/~hgk22/c...1-Lecture3.pdf


Disclosure: I have degrees in Engineering, along with various ties to MIT.

SgtRock

Thank you for the information RedGray. I am looking for information that pertains to the E35 engine. If anyone could tell me more specific information like chain type, when to replace, and expected cost of replacement I would truly appreciate it.

TTMBCLS

I replaced my tensioners at 65k. Just a little worried.. But if have to replace the timing chain the cost in labor will go up.. I didnt hear anything timing chain for replacements for my car yet..so not that worried.

kjb55

There isn't a defined maintenance interval for chain and tensioners. No noises? - I wouldn't even consider changing. You might consider finding a new mechanic.

Russell Ormerod

A 272 engine will trigger a fault for valve timing long before you need to worry about any mechanical issues.

chromJ

I think part of the confusion and conflicting information is coming from the fact that the technology and manufactjring tolerance and quality control is improving.

Back in seventies the timing chain replacement before or at 100000 km is a must.