Fuel filter replacement. With testing on a RS4

B6/7 S4/RS4
#1

So there is always talk about maintenance on your car. Its not a sexy talk but its one that is brought up from time to time when people are looking to see why their cars are not ruining to there optional performance.

One thing that gets over looked from time to time is the fuel filter. Why is the fuel filter a big deal?

Well a clogged fuel filter is going to cause a loss of power. If you own a 2004+ car chances are your fuel pressure regulator is in the fuel filter. This is a big deal when it comes to making big power. You really need that filter and regulator to work properly.

The below video is a test done on a RS4 with a fuel filter that had failed. Not fully failed but, failed or was failing depending on how you look at it.

It was causing a loss of power. Here is the kicker. You wouldn’t know so much unless you were looking observing how the car acted. You could see the fuel request wasn’t quite where you wanted it to be. Still the car for all intense purposes ran fine and fast. Just not as fast as it should have been.

You’re looking at the actual fuel pressure. Please excuse the gauge when the car starts. Its not a real expensive gauge. It should be liquid filled so the gauge isn’t bouncing around like that.

http://audirevolution.net/videos/106/rs4-fuel-low-pressure-test

Now that you saw that. This is how the gauge should look when you key the car up. Notice how the fuel pressure isn’t falling off.

http://audirevolution.net/videos/111/rs4-fuel-pressure-test-good

So why is this a big deal? when you look at how your car is performing you want to look at all the parts. For years Ive been building fast cars and I would always get people saying. “oh well thats not that big of a deal” When you think about it if you have 8 not that big of a deal things is one real large thing.

All the great parts in the world can’t work right if you don’t have the proper support for them. This one test car was a great example. The car was still crazy fast with the failing fuel filter. Now with the change the car just runs better.

My finial thought is. While selecting the proper performance parts are going to win the race for you. By not having the proper maintenance parts and work done you can just as quickly take yourself out of the race by not being able to support your modifications.

Here is how to replace your fuel filter. Please keep in mind I didn’t have a script and I did this filming one handed on my phone. Its an support video. If anyone has questions please feel free to post them. Im sure between all of us we can fill in any and all blanks I missed.

http://audirevolution.net/videos/110/audi-fuel-filter-change

#2

Count dropping another bomb of info there - I didn’t know that a filter could have so much affect on the pressure

Mate that was a steller effort of filming one handed under a car that was on jack stands.

#3

im at work so i havent checked the video out but i could only imagine. ive been preaching fuel filter and spark plugs forever now. i have about 3k on my current fuel filter but it will get a fresh one before i hit the track up when it opens the end of this month.

#4

I didnt realize this job was so simple. I’ll definitely be replacing mine this summer.

#5

yeah I noticed a good jump with my S4 when I replaced the fuel filter, easy and cheap job didnt even have to jack the car up

#6

apparently we have a different fuel filter than the B6/7 S4 so be careful

no I don’t mean 3 line vs 4 line.

I mean 6 bar vs 4 bar. Gotta make sure you use the right RS4 filter. I have a couple of B7 S4 fuel filters at home from my old car (I used to stock up parts) that I can’t use now.

Anyone got a 2007-2008 S4 localish that wants to buy them>?

#7

^
Not a problem. I’ll make sure to order the right one for my RS4.

#8

One of the first things I learned from these forums: Maintenance is key and should always be up to date before modding. I stick to it religiously.

I do my plugs and fuel filter every summer, which is about 7-8k mile intervals.

#9

^^^WHOA!!!

That’s an aggressive plugs interval. 91GL will be impressed. He used to do it every 15 I believe.

#10

They’re only $2 a piece right now on Amazon (after rebate), so why the hell not. Even without the rebate, they’re normally only $5 each.

I plan on going maintenance crazy on the high mileage RS I might be getting.

#11

spark plugs for $2? WTF?

I think I paid like $9/each on my S4.

How’s the RS4 hunt going? Or have you found the target and are just still trying to find reasons to not do it?

It’s funny whenever I buy a car, I try my best to find a better car to buy

#12

Yea, they’ve came down significantly over the past few years. The Bosch 4417 are $5 each on Amazon and Bosch is offering a rebate of $3 per plug until the end of the year.

Still interested and talking with that local QW guy about his RS. Just waiting on it to get back from the shop after getting the rear bumper fixed. Assuming that it’s fixed correctly and it checks out mechanically, I’ll likely have it by the end of next week.

#13

Oh yeah I forgot it got roughed up. Bummer.

#14

Ordered a replacement filter. 46,300 miles, original filter. No issues with my RS4, and let’s keep it that way!

As an aside, in this stock ECS Tuning image, you can see the “6.0 bar” stamped into the end of the cannister.

http://c1552172.r72.cf0.rackcdn.com/28968_x600.jpg

#15

yeah it’s a different fuel filter to the B7 S4

#16

Just adding a nice little image of the RS4 fuel system. Very nice of Audi to allow us to easily change this part, instead of having to open up the fuel tank.

http://farm3.staticflickr.com/2852/9008609902_4557aa6ff1_c.jpg

#17
  • karma to CV.

Your video saved me from possibly breaking a clip on the fuel filter connection. Pictures did not fully register with me. But I went back and watched your video again, and the light bulb went on (however dim) in my head.

After that: clip/clip/clip… remove old filter… add new filter… clip/clip/clip/done. It took longer to clean up the tools and get the car off the ramp than to install the filter.

Thank you!

#18

I’m so glad it helped. I would like to keep doing more of these videos this year, trying to find more needed DIY stuff. Thanks for letting me know it helped.

#19
  • karma to CV.

Your video saved me from possibly breaking a clip on the fuel filter connection. Pictures did not fully register with me. But I went back and watched your video again, and the light bulb went on (however dim) in my head.

After that: clip/clip/clip… remove old filter… add new filter… clip/clip/clip/done. It took longer to clean up the tools and get the car off the ramp than to install the filter.

Thank you!

#20

I’m so glad it helped. I would like to keep doing more of these videos this year, trying to find more needed DIY stuff. Thanks for letting me know it helped.