TomF

Hi all, I have an issue which I suspect is the HPFP. I have done extensive research on the issue and read several excellent threads including https://rennlist.com/forums/cayenne-...1-p1025-2.html

Here are the particulars: yesterday when I got in my 2009 CTTS (116K wondeful miles) there was a faint smell of fuel in the cabin. As I drove to pick up my daughter, there was very mild stumbling and then shortly thereafter the power on the car went down to nearly nothing with almost zero response on the throttle. I was able to limp to pick up my daughter at school and home and when I got home the smell was stronger outside the cabin and I noticed wetness on the undertray which turned out to be fuel. Of course, the car is grounded and will not be leaving its spot until the issue is remedied!

This morning, I started the car and it turned over for about 1 second before starting, which is longer than usual. It normally starts instantly.

I will pull codes with myt Durametric this morning in between meetings and also check the HPFP pressure readings.

Two questions:

First, do the pumps leak a lot when they fail? I was alarmed at the amount of fuel on the undertray.

Second, how do I navigate the morass of rebuilt pumps that dealers and everyone is selling? Any tips for ordering a new pump would be welcome. A new pump, not rebuilt, is about $2100 and a rebuilt pump with the GX suffix is about $1000-1200 less. I would like to avoid the pumps rebuilt in China if at all possible as I have heard they have issues. This may be unavoidable, however.

Many thanks to Don and Rossi for the above listed thread and links out to other info. It was extremely helpful!

Cheers,
Tom

TRINITONY

I got mine from Sonnen and it was roughly $2100 before the core exchange. It was a rebuilt unit which has an X at the end. I think I had a very light leak, not much to think of. I was getting a P1026.

TomF

Thanks for the info. My understanding is that the Turbo/Turbo S pump is more complicated than the NA pump so they are not interchangeble, which is completely understandable. The undertray panel was wet with gasonline in the center, which is very alarming. Here are the codes I've pulled...

The 2181 is a failing thermostat and is on my deferred maintenance list. I have all the parts, so no time like the present! 1026 and 1021 are for the HPFP. 1023 may be a failed coil and mine have about 40k on them, so I will replace all of them again as well as plugs when I replace the HPFP.

For the edification of anyone reading this thread in the future, here are all the threads that have helped me out so far.

https://rennlist.com/forums/cayenne-...placement.html
https://rennlist.com/forums/cayenne-...de-1026-a.html
https://rennlist.com/forums/cayenne-...1-p1025-2.html
https://dorkiphus.net/porsche/showthread.php?t=33572

Cheers,
Tom

hahnmgh63

https://www.sunsetporscheparts.com/o...QtOGwtdjgtZ2Fz
A little cheaper from Sunset. Have you pulled the belly pan off yet to see if you can spot the leaking area?

Pelican for a GX https://www.pelicanparts.com/More_In...110-315-GX-OEM

Don't know anything about this Ebay seller out of Arizona but GX part number?
https://www.ebay.com/itm/32421492704...hoCPPcQAvD_BwE

TomF

I haven't had the time to take the belly pan off yet, but will dig into it in short order, hopefully this weekend. We have a pretty long road trip coming up in a few weeks and it certainly needs to get sorted out and tested for a while before we head out on our adventure.

Thanks for the links.

I have been searching around for the best and most reasonable cost option. This is the cheapest I can find and there is a bit of comfort that it's coming from a Porsche dealer. I suspect that all the rebuilt ones are coming from pretty much the same source. https://www.sunsetporscheparts.com/o...mp-948110315gx

I am still very challenged by the parts numbers in this application. The 948110315gx appears to be the rebuilt number for a 2009 CTTS and the 948110355 appears to be a brand new OEM unit. This issue is that many of the Porsche dealers are outsourcing their online parts sales and there are tons of mistakes that I have observed when looking at various parts. One site gave me the same part number for my CTTS for the 6-cylinder Cayenne! I am ensuring that it specifically lists the engine code for the CTTS engine in it's application listings- M48.051.

The reviews on some of the sites don't inspire confidence- on the Sunset site, on reviewed indicated that he had to try three pumps to find one that works. Ouch.

Cheers,
Tom

bigbuzuki

Is it possible there is a leak in the fuel lines which run from the fuel tank pumps to the HPFP ?

if so, it would explain the fuel smell and also would be starving the HPFP of fuel.

TRINITONY

That's an excellent price from Sunset.

TomF

It sure seems so. I will cast a wide net amongst the dealers when I place the order next week and let you all know what I find.

I haven't had a moment to tackle this project yet and since we are headed into record heat over the next five days, so I think I'll go boating instead...

TomF

Here is a bit of an update. With the record heat behind us (110 in my lakefront town near Seattle), it was cool enough yesterday to ascertain that the HPFP was indeed leaking and I was able to remove it successfully. If you tackle this job, one is doing it completely blind and by feel, and expect some seriously bloodied knuckles as it is impossible to feel the bolt locations through any decent gloves other than simple thin nitrile ones.

The 2009 CTTS has its own special HPFP and the bolt pattern is slightly different from the 958TT and 957TT and NA units. If you have a 4.8 957 CTTS, remove the three 10mm bolts, one short, two on long stems, and leave the adjacent 14mm long stud bolt alone. This 14 mm bolt is in the place of one that you remove on the other V8 Cayennes and Panameras. Don't waste time removing it like I did.

Honestly, the removal was about 90 minutes as indicated in a couple of writeups, and less difficult than replacing the AOS in situ on my 2000 C4 Cab (which Porsche claims requires and engine removal to effect the repair).

Please, please double check the part numbers for your application, as I make no claims to accuracy here and there have been dozens of updates to the various pumps, just like the Turbo coil packs. The numbers as I understand them to be for the 4.8 957 CTTS 4851 pump are:

948-110-315-55 New

948-110-315-5X Rebuilt

Don't trust what is listed relative to part numbers anywhere other than in the Porsche PET and certain dealer websites. Many dealers are outsourcing their online parts ordering to one specific company and I found that nearly every website associated with this company listed the incorrect pump for the 2009 CTTS 4851.

Be prepared for sticker shock: a new unit runs slightly over $2000 and a rebuilt unit over $1600 with a $600 core charge.

For further clarity, the 2008-2010 CTT 4801 uses a completely different pump, which is more available and considerably cheaper: a new unit runs slightly over $1200 and a rebuilt unit over $900 with a $300 core charge.

These are the current part numbers for the 2008-2010 CTT 4801:
948 110 315 07 New
948 110 315 GX Rebuilt

I will update you all when I source my pump. There is one in the Porsche dealer's system, but so far no one has been able to locate it. I am attempting to source one from a reliable source in the EU.

Cheers,
Tom

TRINITONY

Did you try Sonnen? What about the one u posted @ Sunset?

BTW, can you easily reach the rear 02 sensor?

This is outside of the box my pump came in.

TomF

The Sunset unit was had the GX suffix and turns out to be for the 957 NA V8. The website was incorrect about the application. Your box has the correct number for the 957 CTTS rebuilt unit. At how many miles did yours fail? The PO of my car had the HPFP replaced by Sunset Porsche at 74k miles right before a purchased the car and I am at 116k now. Incidenatally, one of the bolts was missing, one was only hand tight, the insulation was clearly damaged installing the unit and I sincerely hope that tech is no longer working at the dealer.

Great thought - I will take a look in the AM regarding the O2 sensor.

Cheers,
Tom

TRINITONY

Ok because I had searched for quite awhile and Sonnen was the lowest price.

Mine failed at just over 100k and appears to be original as the stopper had disintegrated and was black in color. The updated stopper is now white. There was no record of an HPFP being previously changed by the PO or listed on the Carfax. My leak if there was really one was barely noticeable, it was like lil vapor escaping back there, and only noticed it one time. Those bolts have to be tight as they're under a lot of pressure (HP) and maybe that's why it was leaking. That pump shouldn't have gone that quickly as they're built to last a long time. As from searching I didn't find one thread where someone had replaced a CTTS pump in the US. Maybe you want to re-install, properly secure and see what gives or not since it might of been faulty from the get go.

TomF

Interesting thoughts. When I pulled my pump out, the stopper was no where to be found, but it possibly disappeared into the bowels of the suspension and undercarriage and I hope to find it at some point. I looked with an inspection mirror to ensure that there were no parts lingering at the end of the camshaft. I don't know much about the workings of these pumps, but it was clearly leaking from one of the silver mushroom shaped valves.

What I find strange is that the pump was manufactured in 2003 and has the 948-110-315-54 part number for the 957 CTTS 4851 engine. It goes without saying that this is years before the introduction of the 957 CTTS. The 54 suffix was the version the used in 2016 and in total, they have had four iterations for this engine, starting with a 52 suffix.

TomF

As a quick update. It is useful to know that there are earlier versions of the pump (scarcely) available around the world. For the 957 CTTS 4851 engine, there are a few that are suitable in rebuilt form:

948-110-315-55 Current model
948-110-315-54
948-110-315-53
948-110-315-52
948-110-315-5X rebuilt

As of this writing, there seems to be only a few in the supply chain, inlcuding only one rebuilt version of the current iteration, which I just snapped up. Many thanks to an awesome Rennlister who is forwarding me the pump from the EU. I may purchase a second one of the earlier iterations just to have a spare since they are not easy to come by. I guess that's to be expected, with only 309 sent to North America.

Cheers,
Tom

TomF

Well, the saga of sourcing a pump continues... after locating a waranteed rebuild pump from a reliable source in the EU, I purchased it online, only to be told the next day that the pump was actually not in inventory. The same seller had another one, one part iteration back, listed on eBay in the UK so I purchased that one after arranging for a kind Rennlister to forward it on to me...and guess what? The seller cancelled the order as well, this time with no explanation. I have received refunds for both, but not for my core deposit yet....agghh!

I finally threw in the towel yesterday and went back to the dealer network and when I finally got ahold of a nice person at Deleware Porsche, I was informed that the lead time was a minimum of 3-3.5 weeks, maybe more.

Clearly the CTTS is going to remain under cover in the garage for the foreseeable future. I have opted to purchase the pump, with the same lead time, from our friends at FCP Euro for slightly more than the dealer as their lifetime warranty applies to this part as well. I suspect that I won't see the part until close to September as no one really knows how long it will take.

Here is what I can discern:

First, Porsche has a very, very tight grip on the distribution and sale of these pumps. I mean, unbelievably so.
Second, there seems to be only one rebuilder that is attempting to rebuild these units and Porsche, I suspect, has them locked into an iron-clad agreement not to sell to the US outside of the Porsche network.
Third, Continental, the manufacturer of many of the DFI pumps for Porsche in the past (including mine) is, as of 2019, no longer in the HPFP business. Smart move as it seems there are a ton of failures on every platform of the marque.
Fourth, do your homework on the part numbers. As I mentioned in a post above, nearly all of the dealer and other websites are incorrect.
Fifth, do not have a HPFP failure on a 2008-2010 CTT or CTTS during a pandemic and major supply chain and shipping delays!

Cheers,
Tom