Can a High Pressure Fuel Pump just fall off?

[matapaca]

Hello All

I have a 2005 Audi Avant 2.7tdi with 129K miles and a number of problems - limp mode with glow plug warning light and emissions warning light.

I've just had the glow plugs and inlet manifolds changed over and while doing the job it was clear that the bolts form the high pressure fuel pump had come loose and the unit was moving around on it's brackets.

In January 2015 MDM replaced a broken bracket and removed a broken stud and fixed the issue with new audi parts however in just over a year all the bolts have come loose.


https://youtu.be/u4VOGOBj_BQ

I have search the internet and this forum but not found any mention anywhere.

Is this a common issue with Audi HP Fuel Pumps?

[matapaca]

OK after a little searching around I found "2004 - 2006 the crankshaft vibration damper was poorly produced"

Excuse my ignorance but does the same belt for the crankshaft to the fuel pump (as well as alternator, water pump, power steering pump (http://shop.ebay.co.uk/?_nkw=power+steering+pump) and air conditioning compressor)?

It may well explain why the original problem with the HPF pump i.e. a broken bolt and cracked bracket might have happened. And why the bolts have come loose again.

thanks
Matt

thanks

[B5NUT]

That a is a different belt.

[dan2485]

If the threads to the bolts holes are worn then the pump could fall out especially if the bolts were over tightened when fitted.

[matapaca]

That a is a different belt.
thanks for clearing that one up, shame I thought I may have hit on the answer.

[matapaca]

thakns for the input, I will suggest on sorting it out they use threadlocker cheers

[dengsx]

Hi there,

Sorry I know this is an old thread but I have the same problem and its driving me insane!

I see the OP is no longer active on the forum but am wondering if anyone else has had this..? Mine has come loose twice now and its such a pity as otherwise I am loving the car! ('06 A6 2.7Tdi Saloon BPP Engine)

If anyone has some advice I would be really grateful!
Many thanks
Denis

[B5NUT]

I would get new bolts and apply thread lock, that should resolve the issue.

[dengsx]

Hi B5NUT,

Sorry long time to reply, thanks for suggestion.

I have pump back on car, but have only driven it rarely in the past while. I originally thought there was vibration elsewhere that was causing the pump to shake loose and fall off but after looking at it again with some friends, I have to accept it could be the pump itself. When I had the car in an engineering/fab shop to get new sleeve and fasteners welded/drilled onto the engine, he said he thought the damper pulley and belt pulley were not running true, and this could be caused by play in the shaft etc. (He put a dial runout gauge onto the pulleys while the pump was held in a bench vice).

So to cut a long story short I am getting a 2nd hand pump and should be able to fit it next week. Yes theres a risk with anything used, but in general the CP1 pumps seem to have few issues...

I have a Vag Com cable coming from Gendan also, and have emailed Ross Tech on how I might be able to code in a different pump. I will use new bolts and thread lock when I fit it.

BTW to B5NUT - your build thread was absolutely EPIC, I am hoping to carry out a few mods similar to yours!
Cheers
Denis

[Crasher]

Dengsx, your 2.5TDI uses a different pump system, a so called VEP unit (VP44) and the other cars in this thread are common rail with a single output high pressure fuel pump.

[dengsx]

Hi Crasher,
Sorry my signature was out of date. I have changed it now to show my current car - 2006 A6 2.7TDi Quattro Saloon BPP Engine.

[Crasher]

I have never seen one of those come adrift but crank damper (or is it dampener?) failure is still a problem on the 2.7 even with the updated part and the resonance from this certainly could make the pump come loose.

[dengsx]

Thanks Crasher.

Can I test this damper for failure - e.g. try and wobble it to see if any play in it? Maybe you have to remove the belt to test it properly - and then might have to unbolt front slam panel to get access to it, or maybe it can be done from underneath...

Funny thing is I have always had a little vibration on the car, especially at motorway speeds. Up to now I thought it was the wheels or tyres, but have replaced all of those in last few weeks. If it turned out that the crank damper was faulty, it would explain a lot of my issues!
Cheers
Den

[Crasher]

Sometimes you can see it wobble but testing it for movement means removing the belt tension which means a strip down.

[dengsx]

Thanks Crasher I will test it for movement asap
Den

[dean warren]

Ive had my pump bracket snap twice on my a6 2006 3.0. Audi now tell me the part is on back order, but i would check for broken brackets holding the pump, my alloy bracket snapped at 5he bolt hole on top of the engine screwing down. And rear tin bracket had also snapped.
Fuel pipe fracture was the 1st i new about it.

[B4XT3R2020]

Hi, did the same problem ever reoccur? Twice mine has broken brackets but I can't find the source of the issue, any ideas?