04 Cayenne - Fuel Filter and Pump Replacement
 

Just finished replacing my fuel filter and both fuel pumps. The problem began with stalling after a good start. I perused the forum and tried to avoid opening up the fuel tank, so tried replacing the evap valve per another posting on this forum. When that didn't solve the problem, I replaced the fuel filter - to no avail. I then pulled the fuse (fusebox located under the hood) for the left pump - car wouldn't run. Then pulled the fuse for the right pump (fuse slot 14), and the car ran, albeit not very robustly. Since I was going to have to open both access holes to the fuel tank, I decided to replace both.

Difficulty level overall: Difficult, but doable if you are mechanically inclined. Replacing the fuel filter and/or fuel pumps requires you to access the fuel tank, which is quite dangerous.

Recommendation: If you don't have the time, patience, tools, safety equipment (fuel resistant gloves, carbon filter mask, etc), I don't recommend you try this.

Recommended references Download the Cayenne repair guide. This is a general service guide and provides general procedures and pictures (there are a few sites online. Just Google Porsche Service Manual). The one I downloaded assumes that the reader is somewhat familiar with Porsche systems and is NOT a step-by-step. Still a must have.

Recommended Tools: For you Porsche owners, this is old news and "par for the course." You will need special tools to replace the fuel filter and pumps. First, to access the fuel filter/pumps, you will need to remove the seatbelt brackets located in the passenger seating area. They are held down by proprietary 12-point torx bolts. DO NOT USE a normal 6-point torx driver even if it seems like it will fit. YOU WILL STRIP the heads and that creates a whole other set of problems. Bear in mind, these bolts are LOADED with Lock-tite, and they are a PITA to remove. You can purchase a 12-point driver/socket at O-Rileys. You can also find a VW special tool kit on Amazon. Just google 12-point torx to find a convenient source.

You will also need a special tool to remove the retainer ring that holds down the fuel filter (driver's side under back seat) and the fuel sending unit (passenger side under back seat). I read that some have used a screwdriver and a hammer to remove these retainer rings. NOT RECOMMENDED. The tool (part number T10202) is required because this retainer ring effectively holds back the fuel from entering the vehicle. It is required that you torque this back on to 104 ft/lbs of torque. You won't even get close with a screwdriver and hammer when you try and put this back on. I bought mine online at snapon.com for $44.00 and it got to me in 2 days (ground shipping). Worth it! And, you will see it is the same tool for VW's as well. As long as the part number is the same (T10202) it should fit.

Safety Recommendations:
1. Disconnect the battery. It is under the driver's seat. To get to it, you will need to remove the carpet-covered plastic tray-like cover under the driver's seat. Reach under and gently lift up on this cover, and it will pull right up. Then pull back the carpet (pull towards the front of the vehicle - you may need to remove the 2 plastic trim covers that hold the carpet down) to access the 2 12-point torx bolts that hold down the front seat. Once removed, slide the seat back to it's farthest position, and recline the seat forward. Lift up the seat and it will tilt backward (there are 2 plastic trim pieces on the back side of the support rails which will prevent you from fully tilting the seat back, which will need to be removed).

You will see the cover to the battery. Unhook the 4 clamps on each corner and lift up the cover. Disconnect the negative cable, put the cover back on, and tilt the seat back to its normal position.

2. Relieve the fuel pressure in the system. Remove the gas cap, and then you will need to access the "fuel gallery" under the hood. The best way to get to this is to remove the plastic covers on the driver's side covering the injectors, etc. Be careful or you will scratch them. I recommend you download the service manual mentioned above, and there is a good step-by-step. Once you have the covers off, the "fuel gallery" is the y-shaped tube (carries the fuel around the injectors) that runs on both sides on the intake manifold. It's the only silver metal tube there. On the very front ends of this y-tube, you will see black twist-off covers (similar to those found on a tire valve stem). Remove these and you can access the relief valves (they look like the inside of a valve stem). Depress the center, and fuel will come out (BE READY. HAVE RAGS or appropriate fuel cloths to catch the fuel that is released. RECOMMEND you do not let the fuel leak onto a hot engine. Possible fire, etc. Even with relieving this pressure, you will still have some residual pressure in the system, and fuel will leak out when you begin to disconnect the lines attached to the fuel filter, and fuel sending unit. BE READY with a rag or appropriate fuel resistant cloth - or fuel will leak out onto your seats and carpet.

3. DRAIN YOUR FUEL. I have read that some have replaced the fuel filter and/or pump(s) while the fuel tank is full. I don't recommend this, but it has been done (even the local Porsche dealer confirmed this). I didn't have the $10,000 professional "Fuel Caddy" that siphons out the fuel safely (like the dealer does), but I had less than half a tank. Still, I made sure I grounded the car, and kept contact with the vehicle to ensure no static electricity. Something you want to avoid given the fuel tank is open.

4. Buy a carbon-filter mask. I have read that some have just "toughed it out" and breathed in the fumes. NOT RECOMMENDED. Ensure your mask is new or that the carbon filters have been replaced. You DON'T want to sniffing these fumes.

5. Buy fuel resistance gloves. Easy to find at auto- or hardware- stores. I used a combo of Nitril gloves, and when I had to pull out the pumps that were 3/4 covered in fuel, I put on longer/thicker chemical resistant gloves (not neoprene), as I had to submerge my hands in fuel to get the pumps out. They are removed by twisting 90 degrees to the left. Not easy since the access hole is just enough to fit one hand in at a time. Be careful to to inadvertently crimp, twist or break any of the connectors. For the most part, the new fuel pumps will replace many of the tubes you will see in the tank, but not all. It's the other ones you don't want to break.

6. Buy a flexible metal "grabber." You WILL either drop something in the tank, or inadvertently drop one of the many hoses or connectors in the gas tank during the process. Make sure you touch this grabber to the car to ensure no static electricity before using it (EVERYTIME). I know I sound paranoid, but believe me, I didn't want to have admit to the wife that I just blew up the car, etc.

Lastly, once you gain access to the fuel pumps, you will see a spider-web of plastic tubing. It will look overwhelming. Take the time to print out the fuel pump schematic located within the service manual (mentioned above - the dealer can also print you out a picture, but it may not have the detail like the service manual does - at least the one that the dealer gave me didn't), mark the tubes (I tied strings to each to avoid having to fish them out of the tank). This is silly, but to avoid problems later when pulling- or inserting the new fuel pumps, make sure your string is long enough because the pumps barely fit in the access hole and you will not be able to tie-up the hoses outside of this access hole and still have enough room to pull out or put in the pumps simultaneously. When pulling out the pumps, BE READY. They are full of fuel. DO NOT TRY TO EMPTY OUT the fuel contained within the pump by tilting the pump while over the fuel tank access hole. Doesn't work. I wound up soaking my carpet with fuel. COVER THE AREA with clean rags, etc., to catch any spillage. Carefully remove the fuel pumps (full of fuel), and place them in a metal container that can be sealed. I bought a small metal trash can with a lid. I plan on disposing appropriately. Maybe by taking them back to the dealer or an auto shop, or...

Conclusion: I actually enjoyed doing this and the impetus was that I knew I would be saving at least $1500-2000 labor (I live in Silicon Valley and the labor prices are no where near what I have read on this topic). The associated costs of parts were: $272 each for the pumps (original quote was $370, but I showed the dealer the online prices from partsgeek.com, and they brought down their prices a bit), $176 for the fuel filter, $18/each for the fuel tank seals (the safety bulletin recommends you replace these), $10 for the (8) 12-point bolts that hold down the back seat-belt brackets (these are 1-time use bolts, so don't reuse your old ones. The news ones will already be loaded with Lock-tite), $12 for the 12-point torx driver from O-Rileys, and the Service Manual download cost me $29, and is a .pdf. Good future reference. Total cost was around $800 plus tax.

Good luck.

Great DIY..

A few comments/additions:

- Tools - the fuel pump ring removal tool is available from other sources - Google the tool PN. I've seen them on Ebay for around $20 listed for a VW (same tool.) I agree - the screwdriver/hammer is really a bit primitive. Point being - there are probably less expensive sources for the tool then SnapOn.

- The 12-point Torx is commonly called a "triple-square" (3x4 points) - you can find it using that search term in Google. I got a set of them for around $15 from Amazon, surprisingly good quality. There are other places on the Cayenne where these bolts are used.

- Relieving fuel pressure. A bit easier to simply pull the fuel pump fuses before disconnecting the battery and run the engine until it stalls (a few seconds usually.)

- Getting to the top of the tank and pumps. The carpet must be cut over the fuel pump access ports (there are very slight dashed-lines in the carpet to indicate where to cut) and the metal cover that seals the body must be removed. The cover is held in with 4 bolts IIRC. Once you remove that you'll see the top of the pressure-regulator (right side of the vehicle, aka passenger side in US, aka starboard in nautical terms) and the fuel filter (driver side, left, port). These must be removed to access the pumps. Lots of hoses and wiring.

Very nice writeup..! Kudos!

MJR - Get write up on the replacement procedure. Taking your advise and getting ready materials to change the fuel pumps and filter. I was wondering how long it took to change out everything? i.e. 3-4 hours? Love working on the car, but have family obligations too. Thanks.

I just called my Indy and he quoted me $1050 for parts and labor to change both pumps, filter, gaskets, vent hose. It was like $750parts / 300labor. I had my primary fail this Friday while on a road trip. He said I didn't have to change both pumps but recommended it.

I agree. I had the same problem some month ago. The porsche mechanic told me just change one. Was a mistake. Some weeks later the other one failed and i had to do same job again

Easy....but not really. Need help..
 

Easy. 2 pumps and two new flanges and seals. Everything fits as it should. Ther was practically a beach in the bottom of the tank right side. Filter was disgusting, solid greasy black. Unreal. Car starts perfectly runs smoothly. Can't wait for a test drive.

Update:

Initial drive was very good, however when I took the car out this morning it died while filling up the tank with gas. I could not get it to start/stay running without switching to the number two pump by pulling the 14 fuse The fuse for the number one pump was lost initially so I replaced it yesterday after repairs with a 10 that keeps blowing. I changed to a 15 but same sputtering then stall. Full tank of gas shows only 7/8 full. My thought is a float on one side is being pinned down by the fuel lines inside the tank. The sputtering and dying after start up is what made me replace both pumps and the rest in the first place. The fuse blowing on the #1 pump is very perplexing.

Another thought is perhaps a sucking jet on one of the pumps is not positioned properly and thus causing some problem, however if it were loose in the tank it would still be sucking fuel just not from the pump top. Perhaps a electrical connection inside the fuel regulator or filter pump could be inverted/polarity? There is an electrical connection on each flange which could be connected either way as it's a spade connector and no clearly marked polarity. Any ideas anyone? Please help.

Hi there! Newbie here. Need some help. According to what I've read so far, the left fuel pump on my 04 Cayenne S has or is failing, as per the tests, I removed fuse 14 and engine did not stall. I'm going to replace the pump and filter, so I have to order the parts. My question is, can the truck be driven safely with only the right pump running?

Replace it all and spare yourself the agony of going back in when the other one dies. Pulling that fuse merely allows the secondary pump to take over and power to primary on left is cut off. I've been troubleshooting and figured out the crimped line, crimped sucking jet and a bad locking clamp that blows off upon pressurization are my issues and yes you can drive just fine on one pump but not at full performance. Save your old parts! I might need a connector! Get a high quality 3M mask and long gloves that withstand solvents. Drive the car nearly empty. Pay attention to hose connections although they are sized to only fit one way and avoid confusion.

Fuel Filter replacement
 

Just replaced fuel filter and 2005 CTT with 55k miles. When I went to start the battery was dead....Charged overnight and now all it will do is turn over but will not start any ideas? Ran fine before.... was fixing car to make the gas smell under the left rear tire go away. Well the smell is now gone. Also tank say 50 miles till empty.

Any help would be appreciated

hello, owners of cayenne
 

i write here just a trick for owners of cayenne if they have a bad situation with that pump!
i remain night on almost -20degree celsius on the mountain in austria with broken principal/primary pump!
i write a simple solution wich can help you temporary to can continue your way! (until to a 'doctor')
take out both aluminium covers .. (you have a 10' key in trunk factory set .. closer to reserve wheel) there in left site unplug connector (primary pump), from that connector to right side make a strap from + pump 1/principal/primary to 2/secondary/second pump the (+) wire have red and is in one extreme ... at plug is 4 wire - 2slim + 2thick .. both thick is from pump (they use color code at wire red= + ) ... maybe that can save lives!
not connect back the plug for pump 1 !!! .. maybe will start and this is a problem for electrical part to suply energy for 2 pumps in the same time.. if is projected for 1 pump the electric part/fuse/transistors/etc.!
second pump work after your engine rich 4000rpm! you can hold your car in manual drive with hich rpm... but it's hard and maybe can broke another part!

https://cimg9.ibsrv.net/gimg/rennlis...f5f22709d7.jpg
I recently replaced both pumps and the filter. This thread was very helpful. The missing info everywhere I looked was a clear and decisive diagram and instructions where all the hoses go. So I attached them on the shop floor once I figured it out. I also found a great comment from another page that helped understand what hoses go where, once the new fuel pumps are installed. This info and photo should save anyone down the line a lot of frustration.
1. The filter (driver's side) has a hose with a 90-degree female fitting. It crosses to the passenger side and attaches to the FPR male fitting that points downward toward the bottom of the tank.
2. There are two hoses in a "Y" coming out of the passenger pump. One is male and the other is female. The female attaches to the FPR on the remaining male fitting. The male end attaches to the long hose that comes from the center of the driver's side pump once it has crossed to the passenger side.
3. The long hose coming out of the passenger pump crosses to the driver's side and attaches to the filter. Only one of the two male fittings on the filter will accept this hose. The other male fitting on the filter accepts the medium-length hose coming out of the driver's side pump.
4. The short hoses coming out of the center of each pump accept the male hose fittings that are attached to the in-tank orange tubing that are coming from the Sucking Jet Pumps. Take note when disconnecting the shortest hoses on each of your old fuel pumps, so you know what they go to when re-connecting the new fuel pumps. The sucking jet pump hoses will be the only hoses left in the tank with male fittings, once you pull the old ones out.
5. There are also two black hoses coming from the sucking jet pumps with clips on the ends that will snap into place on top of the fuel pumps.
6. Sucking fuel pump hoses not shown in image, as these stay in the tank.

Steve - I'm going to take your posting and make it into a DIY.. thanks much for the clear photo.

DONE: https://rennlist.com/forums/cayenne-...p-routing.html

For a first posting - that was exceptionally useful! Thanks much!

Cool, happy to help others.

2005 Porsche fuel pump replacement.
 

Hello,

I recently ordered two new fuel pumps, as my left/driver side fuel pump failed. I noticed that the new pump had one fuel line coming out of it that was about 1/2 the diameter of the fuel line on the old pump I removed.
I first replaced the left fuel pump with the new pump and kept the old right pump in, and the car was able to start and run ok. I decided to also replace the right fuel pump, because it was aging too. After replacing the right pump, the car stutters for about 10 seconds and then stalls. Could the new small lines not be getting enough fuel to the system? Also, on the fuel filter, the line that connects from the right side to the left fuel filter doesn't fit well onto the fuel filter connector. Lastly, where should the short hoses connect? Just to double check, I connected both the short lines coming out of the pumps to the sucking jet lines, just as recommended on previous diagrams. Now, the short lines are the ones that are 1/2 the diameter of the old pumps line. Is that the new design by Porsche for the fuel pump. Is it able to get enough fuel into the system?

Here is the photo of the pump:

https://cimg3.ibsrv.net/gimg/rennlis...0f9ddba969.png

Hi have you managed to get a solution? I have the same problem, old pump 4 hoses.... new one 3.