Why do all of Roehl FRL backfire thru the intake

It is simple just replace the egr valve and it is all better. Just another example of washington sticking its nose where it does not belong.

 

Yup- if Uncle Slam would stop regulating every detail of our lives, our trucks would be built to last longer and get better fuel mileage. (That's what equipment owners want).

Instead, they are built so that they don't violate any of the safety or pollution control laws. In other words, the trucks we drive were built for Uncle Slam, not for us. In the end your new truck will almost always be towed to a shop for repairs by an older model wrecker. (A real truck).

 

The backfire is coming actually through the turbo. Cause? The EGR system is clogging up and not able to control the turbo at high loads. Replacing the EGR valve is a short term fix once this starts because the turbo sensor is already starting to go and the backfires will only increase if the turbo isn't replaced as well. If you are loosing coolant but can't find any visible sign of a leak, it's probable that your EGR cooler has sprung a leak and is blowing coolant through the EGR Venturi which will trash the EGR/Turbo.

 

I have had this happen a couple times usually under heavy load and uphill when i would come out of a downshift. I had no clue, thought i have a injector or something clogging up. Will have to pick up a EGR valve and change it out. Cause I'm not losing coolant or anything and it only happens every now and then. I had the turbo checked 3 months ago and its in great shape. So that must be it.

THANKS I HONESTLY HAD NO CLUE!!! ​

 

I have another question since you seem to be the man who knows. Ever since my truck hit 500k the screen where the odometer is always reads "CYCLE" when i crank it up? what the heck is it wanting me to cycle? LOL it didn't do that before and it goes away once i put it into gear. only when i first crank it up.

 

More than likely, it's always done it. you're just noticing it now.

It's part of the self test that all the later trucks do as part of the pre-igniton process. In other words, it's "cycling" through all the self test sensors. Not a problem.. Normal operation.

"Never ascribe to a malfunction what is operator error." - USAF CMSgt - Da Nang, RVN, 1971

 

If your EGR cooler was leaking, it probably started to carbon up the EGR Venturi and the EGR valve. As that happens, it also starts to affect the control diaphram on the turbo. The carbon in the venturi tube eventually restricts airflow to the point that the turbo vanes aren't opened properly under load and you start to backfire as you shift up under heavy loads. You even have an intermittent backfire while you're rolling down the road in top gear and have to roll up a hill under power. If you are seeing intermittent EGR fault codes, you need to get into a shop as you're going to loose more and more power as the EGR Venturi will continue to restrict exhaust gas airflow and the turbo won't operate at full optimum. I would be very surprised if you don't eventually lose all pulling power if this isn't fixed. Been there, done that. Spent two days at the Freightliner dealer in Troy, IL getting it fixed after ROEHL said they couldn't find anything wrong.... After a FULL EGR system and Turbo replacement, the truck ran great until I finally turned it in.

 

That is all correct... It is only going to get worse, the EGR problems never resolve themselves, as I had one mech at Marshfield try to tell one of my former students. "Just drive it, it will get better, it has just been sitting for awhile." He found himself getting towed into Gary, and getting into a different truck.