HPFP Story

GGK said:

So unlike a hydraulic lifter that has a hardened convex face, the piston in these pumps has a flat face and is not hardened?

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No they have a roller that rolls on the cam (like a PD injector) I dont know but am fairly certain that the roller is hardened.

OP, can you post the image in the thread (the tdi picture gallery is in a separate sign in area and makes it difficult to view). Thanks

Based solely on a picture in which one cannot see what is being described, plus one piece of anecdotal testimony, it may be a little on the early side for charging Bosch engineers with gross incompetence. Not saying the OP is wrong, just that we don't have anything like enough info to pass judgement.

Well, I've got another 2k miles until I re-vist the dealer so they can re-check my FF for more shiny metal on top (assuming the HPFP makes it that long). I will certainly quiz them on this potential issue with the HPFP. I'm now hoping that I do have more metal on the FF as this may help substantiate the "anecdotal testimony."

My shiny metal came from somewhere and there was no water, rust or other contamination when I examined my FF and as noted by the dealer tech upon his examination. My shiny metal contamination occured within a 4k mile window between about 22k miles and 26k miles. IMHO, this is the most compelling testimony / hypothesis yet as to the cause of the shiny metal.

In the words of a very famous German soldier "veeerrrry interesting but not funny"

Look forward to watching this thread and seeing were it goes.

TDI Meister, any thoughts?

mysql said:

As odd as this sounds, I hope this theory is the real cause of failures, and not bad gas.

If it's a design flaw, we have some hope of remedy. If it's simply random "bad gas" and the part is working as designed, we might never have a real work around.

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Bad gas will do it every time. Gasoline, whether good or bad, will kill a HPFP in no time at all.

I'm interested in the root cause(s) too. Time will tell how the HPFPs in CR TDIs hold up.

Is this same pump used in Europe and other parts of the world? If so, the above hypothetical design flaw would manifest itself in much greater numbers overseas due to simple math.

The piston starts to intermittently seize inside it's bore due to fuel lubricity issues or contamination, allowing the roller to lose contact with the lobe. The chain of events leading to galling and failure happens fast after that.

This is nothing new.

True, it's not new, but the bore on the pump did not show visible wear. The pump looked essentially brand new otherwise. But man, that roller and cam were ugly.

Here is the pic I highlighted. Again, I'm sorry that I did not take photos, but just the fact that I got to see one after the fact, made my mind up to get an extended warranty for piece of mind.

this is getting ugly

Did you see the actual bore of the HP section (quite small) or the bore for the lower follower cup?

The HP section was completely disassembled from the main pump assembly. there are two small o-rings that seal that area, with the o-ring bosses inside the main pump casting. I had this section in my hand, with the spool removed, and I saw no visible scarring that looked remotely as bad as the bottom end.
You would think that because this setup pumps the metal throughout the fuel system, you would find a lot of wear marks and scarring wear all through the pump assembly, but to my eye, it was very minimal.
The majority of damage was at the cam lobes and the roller on the bottom of the piston.

Although I would never do it, if a person had a new cam, piston and spring, I believe a person could do a dirty fix of a pump to get it serviceable until a new one was available. It looked that clean inside.

So now should we be checking for early wear on the cam lobe/roller as a signal of possible failure? (where have I heard this story before?)

So how does this theory deal with the fact that none of the cars that are running fine, but have flakes in the fuel filters (about half of those cars whose owners checked the filters) have subsequently failed? I'd assume that if my piston rotated, and then I drove thousands of miles, that I'd see some effect. Also, if the piston rotated, wouldn't that change the throw of the piston, and hence, radically alter the performance of the pump. And do y'all really think that Bosch and VW let such a simple mistake, one that you can figure out by looking at one failed pump, go by so easily. And why are the failures clustering in the US and not Canada or the EU? Come on people. I know everyone wants to see a simple fix, but this ain't it.

If the piston only rotated partially and not 90 degrees, I would think you would see just the beginning of the issue. It just so happened that the pump I saw had already bit the dust, along with injectors, etc.
The design allows it to happen, and the pump moves at xxx rpm from the timing belt, so, partial rotation for xxxx pump cycles until the roller and cam finally meet at 90 degrees, then finally, failure. Of course this is pure speculation, anyone want to pony up for a pump to test with?

Someone said on this forum that eveytime he got rid of a VW he said "Never Again!" then went out and bought another one.
Owning VW's is like being addiced to crack cocane, you know it bad for you, destroys your life, yet there you are on a Sat morning kicking tires at the VW dealership again...

Mazda has a 2.2 ltr Diesel in their new Mazda 6
Hyundai has developed a new 2.2 ltr Diesel for their Sonota
Ford has thousands of Diesel cars running around the world
Subaru builds a 2 ltr Diesel for their Legacy wagon right in their U.S. factory.
Hell, you could even buy a Toyota Corolla with a 1.8 ltr diesel back in 1985.

When will we ever learn..?

longo said:

Someone said on this forum that eveytime he got rid of a VW he said "Never Again!" then went out and bought another one.
Owning VW's is like being addiced to crack cocane, you know it bad for you, destroys your life, yet there you are on a Sat morning kicking tires at the VW dealership again...
When will we ever learn..?

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Nope. Not me. The first time, shame on the automaker. The second time, shame on you for begging for more punishment. There's no second time with a bad experience, for me.

There's plenty of choices in the automotive marketplace. To get fixated on one particular brand is too limiting for me.

I hesitate to comment specifically on this assumed reason for failure, however, most mechanical devices that operate in a similar fashion are designed so that the 'piston' on the cam lobe DOES rotate and failure usually occurs when the piston DOES NOT rotate (a cam lobe and flat valve lifter come to mind).
auto10x
Bill

But if you actually saw a picture of this setup you would see that rotating this item is bad, unlike a lifter and cam. There is a pic here some where that shows the interaction of the two.

I'm reading more and more about this, a week before I take delivery of my 2011 GSW, and starting to crap my pants. I am just coming off of an Audi A4 2.0T FSI and had a very similar issue: HPFP failure resulting from the cam lobe which drives the HPFP being too soft, which allows for scarring on the lobe surface. This breaks down the cam follower (not a roller follower like this, just like a thimble), then the fuel pump. $4k and 3 weeks down the road, and it was fixed. I was out of warranty (but only 40k miles), no joy from the dealer OR AoC.

I've queried the dealer on this and they're telling me it is bad fuel, and are not seeing very many examples of this in Canada (the ones they ARE seeing still have travelled to the US, possibly using non-ULSD [which I didn't think you could even buy in the US], contaminated or poor quality fuel, leading to the contaminated fuel system/destruction following.

I've heard several people explain this matter of factly due to metallurgy, or bad fuel, or production range issues. Has anyone heard of this in a Canadian car that's never travelled to the US, or never had this explained as fuel quality problems?

In the Audi, I kept the parts that were replaced, just mind blowing. This is a potential issue on all 2.0T FSI gasoline engines from VAG, as I've since had Jetta owners, Seat, and other Audi owners join a FB group I started (http://www.facebook.com/?ref=logo#!/group.php?gid=235507629582&ref=ts) but unfortunately was never able to get joy from the dealer or AoC

there is a place in the middle of nowhere in eastern NC that appears to be selling the old stuff. I did a triple take when I read the sign on the pump. It said something like "do not put this fuel in any 2007+ vehicle". Granted, they might have ULSD in it now, and that sticker is really old from when they made the changeover. Glad I have a non-common rail Jetta. I filled the tank with that stuff

Sella Turcica said:

there is a place in the middle of nowhere in eastern NC that appears to be selling the old stuff. I did a triple take when I read the sign on the pump. It said something like "do not put this fuel in any 2007+ vehicle". Granted, they might have ULSD in it now, and that sticker is really old from when they made the changeover. Glad I have a non-common rail Jetta. I filled the tank with that stuff

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When IL first started putting these stickers on pumps, the stickers were worded incorrectly and stated something to the effect of "This is Ultra Low Sulfur Disel. NOT RECOMMENDED for use in 2007+ Highway diesel engines.."

I saw this all the time until maybe a little over a year and a half ago when I started seeing replacement stickers being placed over the incorrectly worded ones that stated "Required for use in 2007+ highway diesel engines.."

dzcad90 said:

When IL first started putting these stickers on pumps, the stickers were worded incorrectly and stated something to the effect of "This is Ultra Low Sulfur Disel. NOT RECOMMENDED for use in 2007+ Highway diesel engines.."

I saw this all the time until maybe a little over a year and a half ago when I started seeing replacement stickers being placed over the incorrectly worded ones that stated "Required for use in 2007+ highway diesel engines.."

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Wow, that sort of thing sounds like it would potentially explain a lot...

longo said:

Someone said on this forum that eveytime he got rid of a VW he said "Never Again!" then went out and bought another one.
Owning VW's is like being addiced to crack cocane, you know it bad for you, destroys your life, yet there you are on a Sat morning kicking tires at the VW dealership again...

Mazda has a 2.2 ltr Diesel in their new Mazda 6
Hyundai has developed a new 2.2 ltr Diesel for their Sonota
Ford has thousands of Diesel cars running around the world
Subaru builds a 2 ltr Diesel for their Legacy wagon right in their U.S. factory.
Hell, you could even buy a Toyota Corolla with a 1.8 ltr diesel back in 1985.

When will we ever learn..?

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Let me know when any of those are available for sale here in the USA.

JM Popaleetus said:

Let me know when any of those are available for sale here in the USA.

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The Mazda diesels will be here for the 2012 model year, but I don't think they've announced which models will get it. I'd vote for the return of the 6-wagon or sport back.

I just did a hasty web search of Mazda diesels. It's an interesting read. One site is from England and if you scroll down a few posts there's mention of 2008 Mazda common rail engines having problems with high pressure fuel pumps failing!

http://www.honestjohn.co.uk/forum/post/index.htm?t=57267

Thanks rtj.
Car change time comes with the 08 registrations, which gives time to decide which cars to view /sit in /test drive / price up.

Since I'm decided on a diesel there seemed no point in going through the process with Mazda if they are still using the same rogue engine for their new 2008 Mazda 6.
That was my enquiry.

On the other hand if Mazda has solved the problem of-

"...failed high-pressure [Denso] pumps and serious lubrication issues leading to total engine failure.." [to quote a fleet manager]

then they are excellent value. But when I read elsewhere on this site about the level of failure and-

"Second-hand engines [there are two versions] are in huge demand and cost over £5000 - even with 50K on them."
It did set alarm bells ringing.

James

longo said:

Someone said on this forum that eveytime he got rid of a VW he said "Never Again!" then went out and bought another one.
Owning VW's is like being addiced to crack cocane, you know it bad for you, destroys your life, yet there you are on a Sat morning kicking tires at the VW dealership again...

Mazda has a 2.2 ltr Diesel in their new Mazda 6
Hyundai has developed a new 2.2 ltr Diesel for their Sonota
Ford has thousands of Diesel cars running around the world
Subaru builds a 2 ltr Diesel for their Legacy wagon right in their U.S. factory.
Hell, you could even buy a Toyota Corolla with a 1.8 ltr diesel back in 1985.

When will we ever learn..?

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Dude, you need to get out of my head. Seriously.