Thoughts and advice on the care and feeding of fine automobiles from Machine Aficionado and bestselling author John Elder Robison, owner of JE Robison Service in Springfield, Massachusetts


We are independent restoration, repair, sales and service for Audi, BMW, Bentley, Jaguar, Land Rover, Mercedes-Benz, Porsche and Rolls-Royce automobiles.

Bentley archives

Land Rovers


How old is that fuel filter?  Should it be changed?

We ask that question every time a fuel injected car comes into our shop for a check-over.  Modern fuel filters are generally metal, so we can’t see inside.  That leaves us one evaluation option – age.

Most carmakers recommend fuel filter replacement on a three to six year interval.  How do you know when that time is passed, if you have no records?  The obvious answer  . . . read the date code from the filter itself.

If you have a Bosch filter (Robison Service is a Bosch authorized service center) you can find and decode the date stamp.  Here’s an example.























The part number – 0 450 905 295 is the biggest and most obvious number, as it should be.  The number in the oval (957) is the factory code.  The date code is the dot matrix printing at the edge.  In this case the code reads 863.13.1.06

We turn to our Bosch date code index to decode the year and month, 863:








According to our chart, this filter was made in March of 1998.  The next number, 13, tells us the date of manufacture.  The final numbers are plant specific, identifying a particular assembly line or location.
Seeing this part on a 1999 Rolls Royce we can say with some confidence that it’s the original filter.

What if the date code is newer?  How closely can we date a filter on a car from these numbers?  The answer – not too close.  A check of brand new filters from Bentley revealed date codes from April 2010 to June 2011 in August 2012.  That suggests filters for high end cars may sit in warehouses several years before being installed.

A check of date codes on higher volume Mercedes/BMW/Audi filters shows much quicker turnaround.  The filters on their shelves left the factory 2-4 months previously.

So what’s the rule of thumb?

In our shop, if we are looking at an exotic or rare car, I’d allow 2 years for a filter to sit before being installed, and I’d expect it to last 10 years in light use.  So I’d replace any filter whose date code was more than 12 years in the past. 

With a more common car, I’d look to replace any filter whose date code was more than six years in the past.

These are the rules we apply at Robison Service, but your mileage may vary.  Obviously a load of bad gas can clog even a brand new filter, and some filters that are a decade in service are as clean as when they were installed.

Till next time
John Robison

1 comment:

Frank said...

Yes I'm trying to get some information and or guidance. Recently while driving to work on the interstate I struck and ran over something that fell from the under carriage of a semi truck that was driving in front of me.

The object struck the front bumper of my truck and then impacted my undercarriage causing a loud booming sound.

I pulled off to the shoulder of the interstate to assess the damage to my truck. My truck was quickly loosing fluid. I had my truck towed to a local repair shop which was still closed amid covid 19. I notified my insurance and opened a claim to which I was asked to take photos for the adjuster handling my claim.

In doing to I noted damage to my front license plate, multiple deep gashes on the oil pan and a cracked transfer case. I noted impact marks on both the oil pan and transfer case.

I just received a message from the insurance adjuster stating he inspected my truck, he noted the license plate damage, then proceeded to state he did not observe impact marks when inspecting the undercarriage and proceeded to say that what I heard was a mechanical issue of some sort, never acknowledging damage to the transfer case. For some odd reason the adjuster made a point to state he observed recent work done to my radiator and and again insinuated the issue and damage was mechanical.

This is extremely insulting to me for many reasons. First I observed with my own eyes the object that I hit. Second I also observed what appears to be impact marks on the undercarriage. Three I have had the truck for 2 years now and haven't had any issues with it not has there been any radiator work done to it.

I'm trying to get some guidance on how to proceed, it's blatantly obvious my insurance is trying to skirt covering the damage sustained to my truck. I have full coverage and have never made a claim. I would truly appreciate any information on how to proceed and or dispute the adjusters assessment... thanks in advance..

| Designed by Colorlib