Check Engine Light Illuminates After Changing Fuel Filters

[fagnaml]

A week ago I took my motorhome to a truck service facility in Brookshire, TX by the name of "Lube Zone" (which previously was B-Line) for full service - change oil & oil filter, change primary fuel filter, change fuel filter/separator, change air filter, lube the chassis, etc.    After the work was done, the engine had to be cranked a couple of times to clear remaining air out of the new filters / fuel line (Lube Zone technicians pre-filled the fuel filters prior to installation).  At the first turn of the ignition key, the check engine light "came on" which the technicians said was due to the "engine system" detecting a small amount of air in the fuel system.   The technicians said after driving ~75 miles the check engine light would go off.   Well, after driving 90 miles this past weekend the check engine light remains "on".    The "old" filter/separator was an Alliance brand with a clear plastic bowel on the bottom and was replaced with a "new" Fleet Guard filter/separator without the bowel on the bottom (Lube Zone did not have the "bowl" type filter / separator in stock).   I confirmed with Cummins filtration that the "bowel-less" filter / separator installed by Lube Zone was the correct filter/separator for my Cummins 6.7 L, 360 HP ISB engine.

So, the question for the Forum is would changing the fuel filter and the filter/separator cause the check engine light to illuminate as Lube Zone technicians stated?    OR, did something else happen during the hour the engine was not running while oil and filters were changed?    This is the first time ever the check engine light has illuminated.

Thanks for the thoughts and guidance !

[jleamont]

Mike, most likely they created a fault code for "low fuel rail pressure". If the filters were pre-filled it shouldn't have happened.

Do you have the capability of retrieving the fault code? I will say its odd the light didn't go out by now if the issue was caused by air in the fuel system. 

Can you see the filters? Make sure the Water sensor is has the electrical connector connected, if not that can illuminate the engine light. 

[hermanmullins]

There is a connection on the filter. I would unplug and then replug the connector. It may be just not be making good contact, a bad  connector or the tech forgot to plug it in.

Herman

[rsbilledwards]

I for one would request/require a. Change back to the bowl type as it is in your favor seeing if moisture is accumulating where it should and could be drained. 

[elkhartjim]

You can get the fault code from the LBCU by going to the Diagnostic menu.

[fagnaml]

Thanks for the prompt and informative replies!  In addition to your great thoughts, I was able to contact a mobile diesel engine mechanic who serves the greater west Houston area.  He stated that simply disconnecting the sensor from the bottom of the filter-separator can "throw a code".   He also gave an identical response as Herman in that the connector for the sensor on the bottom of the filter-separator may not have good contact.   That mechanic said his first approach would be to disconnect then reconnect the engine batteries which can often clear a check engine code.   If that doesn't work then crawl underneath the engine area and check the sensor connection.  If neither of those actions clears the code, then he or a repair shop need to determine what the fault code is.   I'll disconnect the batteries this weekend an let the forum know if this action was successful to clear the check engine light.

Bill -

With regards to your comment about a filter-separator with a bowel,  the OEM Fleet Guard filter-separator is bowel-less (filter number FS-1065).   Wherever the previous owner had the engine serviced chose to install the Alliance brand filter-separator that had a bowel.   The filter-separator is only visible when crawling under the motorhome which I would very rarely do.  For motorhomes such as mine that has very limited visibility of the engine, do owners spend much time under the engine to "look at stuff" ?   I'll admit that I rely on and trust "my" engine mechanic at RV Masters here in Houston to a good inspection of the engine, charge air cooler, etc. when I take my motorhome to them.    

As an FYI for the forum that all you probably already know, Cummins has a "Shop Cummins" website that provides a list of filters for each type of Cummins engine.  This is the web page for my Cummins ISB 6.7 L engine --> https://shopcummins.com/collections/fleetguard-filters/isb6-7    This web page shows all of the types of filters that could be used on an ISB engine.  To get the "exact" filters used on a specific engine, I learned that by providing Cummins Filtration with the engine serial number, Cummins then can provide the OEM filter numbers.

Finally, a personal frustration thought.   Silly me presumed that just because my "new to me" Newmar was my second motorhome that I knew everything I needed to know about motorhomes.   There are enough differences between a 2016 Newmar Ventana LE and my previous 2007 Damon Astoria that I've regressed in my Motorhome 101 class.   Both are diesel pushers built on an Freightliner XCR chassis.   The Astoria was "simple" from a 12 volt system perspective (only had a converter and no Magnum power control panel), had a pre-DEF ISB engine, no permanent satellite system with Dish Network stuff to learn, etc.   Am I alone in feeling that all that has been learned is not enough when purchasing a motorhome that is 12 years newer than the previous motorhome??

 

 

[jleamont]

Mike, you cannot go wrong with the OEM Fleetgard filters. Hopefully you will never stop learning. there is a lot to absorb, so much most couldn't absorb most of it. 

Glad you are all fixed up!

[fagnaml]

After crawling underneath the engine this past weekend I found the problem with my check engine light and new Fleet Guard filter-separator.   The "plug" for the water sensor was inserted into the "receptacle" of the water sensor but was not in contact with the "pins" of the sensor.  Look closer, the "plug" is not compatible with the Fleet Guard sensor i.e. the pins in the sensor are "centered" while the holes in the plug are off-center.    The Lube Zone oil change business in Brookshire, TX simply stuck the plug into the sensor receptacle but did not check the sensor pins and plug made contact.

Lucky for me, Lube Zone gave me the bowl from the bottom of the old filter-separator which has the original sensor intact.   Houston Freightliner, using my VIN, was able to determine the OEM filter-separator used when the chassis was manufactured, a Rancor-Parker brand filter-separator, which they had in stock.   After an hour round-trip to/from Houston Freightliner I now have a filter-separator that is compatible with the original bowl section which I will install this evening.

The learning for me is don't expect the sensor plug to always be compatible with the sensor on the bottom of every brand of filter-separator !    I'm curious if other owners have had this same issue with their filter-separators?

For reference here are links to my OEM filter-separator and bottom bowl.

Filter-separator --> https://www.amazon.com/Racor-S3226T/dp/B002MBUKFA/ref=sr_1_1?keywords=racor+s3226t+filter&qid=1568051783&s=gateway&sr=8-1

Bottom bowl --> note that the bowl only comes with a port for a sensor!  -->   https://www.amazon.com/iFJF-WF10137-Separator-Systems-33630-33812-33813-33774/dp/B07KR29V16/ref=sr_1_fkmr1_1?keywords=racor+bowl+for+s3226t+filter&qid=1568050336&s=gateway&sr=8-1-fkmr1

 

[manholt]

Mike.  Congrats on a job well done!