Why Refreshing My 25 Year-Old BMW E46 Fuel Injectors Was Worth It
Injector balance improved by 97%, turning a set of uneven, dripping injectors into a perfectly matched set flowing within 1% of each other.
I was hesitant about sending my BMW E46 fuel injectors out for cleaning.
The car ran fine overall, and injector service felt like one of those maintenance items that might not make much difference.
After getting the results back from RC Fuel Injection, I was glad I did it.
For my 2001 BMW 325i with 200,000+ miles on it, the injectors were flowing very unevenly before cleaning:
Injector 1: 150 cc/min
Injector 2: 195 cc/min
Injector 3: 171 cc/min
Injector 4: 203 cc/min
Injector 5: 160 cc/min
Injector 6: 184 cc/min
Four of the six injectors were also marked as “dripping,” meaning they were not spraying fuel properly.
After RC cleaned and flow tested them, every injector ended up between 209 and 211 cc/min, and all spray patterns were rated “excellent.”
The system balance improved from 35.3% before cleaning to just 1.0% after cleaning.
That is a huge improvement.
Old injectors often do not fail all at once. They slowly get dirty over time, which can lead to rough idle, worse fuel economy, hesitation, fuel smell, and uneven performance.
The car may still seem “fine,” but once you see the numbers, you realize how far off things can get.
What I liked most about RC Fuel Injection was that they provided a full before-and-after report showing the flow rates, spray patterns, and balance numbers.
For an older BMW E46, especially one with higher mileage, injector cleaning is an easy maintenance item to overlook. But based on my results, it was absolutely worth it.
Here’s a copy of the flow report from RC Fuel Injection.
