Multiple Fuel Pump Failures- Any Ideas?

[Blake-O]

I have a 2008 RS4 with 75,000 miles. I've had the fuel pump replaced three times in the last 2,000-3,000 miles. My shop initially thought it was a bad batch of fuel pumps, but now they are thinking something else must be causing the pumps to fail prematurely. The shop has been great and all pumps have been replaced without charge, but obviously we want to sort this out.

Any ideas?

[emilio]

how are they failing? electrically, in that they short, open, or otherwise cease to respond? mechanically, in that they take a current but don't move fluid for some reason? does the car otherwise run fine?

if they were failing mechanically i'd wonder about the integrity of the fuel tank and it's internal filter (i think these cars have tank screens). it could be that something is degrading and being swept into the pumps.

- emilio

[Blake-O]

how are they failing? electrically, in that they short, open, or otherwise cease to respond? mechanically, in that they take a current but don't move fluid for some reason? does the car otherwise run fine?

if they were failing mechanically i'd wonder about the integrity of the fuel tank and it's internal filter (i think these cars have tank screens). it could be that something is degrading and being swept into the pumps.

- emilio

Good question- the shop didn't specify if the failures have been mechanically or electrically. Previous symptoms for the fuel pump replacements have been the car failing to start, or, starting but engine sputtering erratically after starting and would die if I did play with the gas pedal. I then let the car sit and eventually it fired up and drove fine.

This weekend the engine sputtered while on the highway driving around 75 mph so I pulled off the freeway and the engine died while on the offramp but I was able to pop the clutch and it restarted, but then drove fine after that. The car started and drove fine this morning.

[badger.]

Have you tried changing any filters in the line (not sure how many the RS4 has). If one is clogged up your pumps might just be overworked. Same thing, check fuel lines for kinks or any other source of restriction. Maybe some crud is floating around in the fuel rail/injectors too?

[Blake-O]

The shop doesn't believe it is an issue with foreign matter in the fuel, but that is a good thought.

The other variable is that the issue seems to only come up in warmer weather.

The shop's current thinking is that something is wrong with the car's electrical system, and that in turn is causing the fuel pumps to wear out prematurely.