Hi everyone. I've got a 2009 q7 and for the past 7 years every 3 to 6 months, sometimes every 2 weeks, the injector seals blow. Recently I've changed two injectors (totally warped)
And seals went again withing a week

What am I missing?
I mainly do highway KMs so I'm guessing I shouldn't have to worry about debris. Fuel is always bp or mobil. Dpf is clean

Any ideas good people?

 

what?? for 7 years you had this happening and haven't got it fixed properly by a specialist?

 

I did the first couple myself at the very start but over the last few years I've been taking it to an Audi specialist that just reckons that it's the age of the injectors but I think he's missing something

 

I think something is being missed, for sure. The frequency and repetitiveness indicates a prolonged high-cylinder-pressure situation. Figuring out why is the trick. Possibly carbon build up? Bad injectors dumping too much fuel? Are you not getting any codes setting in the computer while all of this is going on?

 

+1
The fuel injector copper seals/oil control O-rings (be specific what's failing please) going out repetitively is a symptom, not the actual problem, and your car is telling you there's a problem to be fixed.

You don't mention the mileage, but did mention the DPF is OK, so it's a TDI motor. Buy a VAGCOM compatible scan tool to see what's going on inside of your car's electronic control modules...that'll pull any trouble codes for you to see what the car has to say. I'd suggest you get a really good diagnostic scan tool if you want to troubleshoot & repair this car (Ross-Tech VCDS), or you can get one just for basic fault code reading/clearing, etc., for around $40-$50 USD (OBD-eleven, Carista, etc. that work with smartphones.

If blowing the oil seals out, then that indicates an overpressure situation, like maybe your TDI's oil separator (diesel's PCV) is plugged/failed, etc., but we don't have enough info/details on what is actually happening or how you know the seals are blown, or a full diagnostic scan of your car, etc., etc. to assess the issue. Sounds like you owned the car long time, and fuel injectors last from 120k miles (expected life cycle) up to 186k miles, but bad fuel, clogged injectors, and other fueling issues can damage the injectors, so if the body or spray tips of the fuel injectors are damaged, swollen, separating, misshapen, etc. those are all signs they need to be replaced, STAT. When they are replaced, the new injectors must be coded into the ECU using a VAGCOM diagnostic scan tool (like VCDS) which has this programming access/capability within control modules.

FWIW:
My first car was a used '78 VW Scirocco w/4 cylinder gas engine that made like 80HP, and curiously, when I drove it (revving it near redline like a maniac), the injector seals went out quite a lot too, as I recall. Don't think that's your issue though, as my problem was my right foot.

 

No codes whatsoever.
I have low oil temp so had the thermostat changed and the Audi specialist uses a vagcom device.

 

I sometimes will throw the car into sport mode and gun it but literally on the freeway when driving at 100km/hr
Car is at 230k now.
I have 2 new injectors while the other 4 are the og ones.

Is it worth suggesting a pcv check obviously and a techron/4kk injector cleaner??

 

All can say is it's fairly obvious your mechanic is out of his depth if can't recognize that recurring, extremely frequent failures of the fuel injector seals on a TDI is highly ABNORMAL behavior, and therefore requires actual remedial/basic troubleshooting since the VAGCOM scan tool isn't providing him a direct fault pointing straight at the issue. The thing though, is often you will get indirect faults pop that link back to odd stuff like coolant temperature too low, etc., which on my TDI was related to a vacuum system leak, which then kept the vacuum activated/powered servos/sensors from doing their job, etc., so then a monitored circuit fires off a fault code because the automated coolant valves aren't opening like they should...it just cascades is my point.

If you can't see the pebble hitting the pond, then you should look for the ripples it creates in the water, which will lead you back to it...same concept. The abnormal fault codes have meaning, but it's not always what you think, so look at those in context to your bigger problem, with overpressure or extreme vacuum forming inside the crankcase once your TDI is running.

 

A seven year old problem with no deterioration or additional symptoms is quite odd. Can that even be classified as a problem?

How’s the fuel economy? Does your area do emissions testing?

One of the defining features of German quality control standards is that a component should be predictably reliable, or unreliable. It means the point of failure is quite predictable. In the case of injector seals, it means that if one fails then probably all of them will fairly soon. In reality there are quite a few variables so not every copper washer in an engine has the same heat cycles or movement.

Is the car a workhorse? Do you live at the bottom of a steep hill? Do you regularly have to accelerate quite hard before the engine has warmed up? Are you a bit heavy-handed with fuel additives? This could be down to a seemingly routine event which is just causing higher than normal stress.

Or maybe your dealer got a bad batch of seals and they use them so infrequently that over seven years your car is still getting them from the same batch.

 

Im with you on that one, I find it crazy that anybody would be having same issue for 7 years lol and keeps fixing and keep breaking same thing