Gazmcf

Jason Devereux

I have the exact same issue, the same injector, same connection. Did you solve the issue? I have had the pipe changed and still did it. Car been in the garage 2 weeks now and still no idea as to what is causing the issue.

Nic Browne

Tell me please someone how is this above solved, I have exactly the same thing just happened, I put jubilee clips on now it has burst the pipe, please help , tell me what is wrong

LG27

I have the same problem. Went to the Bosch workshop. Cannot find any fault. No error message, but return pipe bank 1 pops out due to too high pressure according to the tech.
Did you manage to solve your issue.

LG27

hi all. I have a 2013 Q7 3l diesel. All of a sudden it has developed a rather odd issue. On the right hand side of the engine the diesel return pipe from the bottom injector pops off. This puts the engine into a limp mode like action. Once popped back on the car is perfect again. Once I drive again at hih speed the pipe pops off again. No error messages . The Bosch mechanic says due to too high pressure on the return pipe, but cannot figure out why .

Any help will be appreciated

'10Q7TDI_Prestige'

OK, so if no tech or 'Bosch' workshop has provided an answer, and their are no trouble/error codes visible using a VAGCOM/VCDS interface to scan the car, then why don't we look at the rest of the fueling system and the oft-neglected bits of it, such as the diesel fuel filter was last replaced when? A TDI fuel system cleaner/purge was last used when? A diesel fuel conditioner (cleans the tank of microbial growth, water, etc.) Sure, these seem like basic, and unrelated things as concerns a hose popping off, but having clogged injectors or goo in your fuel system/tank, or a clogged fuel filter can create problems for your car primarily because of the restrictions to the flow of the fuel, which then creates a pressure 'log jam', and eventually kills your HPFP, injector seals, etc.

Nobody on this thread has posted any contextual information at all in regards to any fuel system maintenance, or non-maintenance, or other symptoms they may be having other than the 'return pipe popped off'. Obviously, if the pipe is 'popping off', there is a root-cause issue, whether it be a weak or broken retainer, or some other fuel system issue that is causing it to exceed 'normal' paramaters. The HPFP output pressure can be viewed/checked via VCDS diagnostic scantool and compared to what is 'normal'. It is a known fact that the HPFP on the TDI's, as well as gassers, is a weak link in this car as it will 'grenade' at random timeframes. Early failure probably has a lot more to do with the quality of the fuel going into the car, especially in the USA cars, but all HPFPs go out eventually as it is a very hard-working part. Our '10 TDI got a new HPFP in 2019, following it's dieselgate detuning, and it was at 85k miles, for example.

Like everything else on this car, the primary fuel pump/HPFP will have a control unit/sensor/module, etc., that is also possibly involved, but I'd start with the basics of ensuring the basic maintenance that should be done has been done, and do a full scan of the car with a VAG-compatible scantool to see what it's hiding. A standard OBD2 scantool will not reveal the secrets of this car...it doesn't speak German.

LG27

Thank you for this informative reply. The car is due for a service in the next 1500kilometers. It has been serviced regularly as per the 20000km service intervals. I will get the service done and follow your advise. Thank you from Johannesburg South Africa

shawn83

Had the same thing happen to me it was due to a bad injector. The injector stopped working or was working very little so it was over pressuring the return line. The first clip is the only one that just pushes on so that's why it pops off the others are real clips

LG27

Thank you Shawn83. Did you have to test all the injectors or just the bank in which this occurred

shawn83

just that side