Hi Folks, this will be my first post on here, and regarding my daily runner.

A 2011 1.6 TDI  of ~ 146000 Miles

Now on the whole she's pretty spot on, there are however a few niggles that I cant fathom out. 

If you are rolling with the clutch down (say braking to a stand) it will drop to 1000rpm.

One you have stopped rolling the revs will drop to 800rpm, but the engine judders noticeably as it drops these last 200rpm.

Also, since I had an injector fail, there is a very slight judder at low revs under load, my mechanic doesnt seem to notice it, but I certainly can.

Maybe with nothing that she sat for two years without really turning a wheel.

49 minutes ago, Woosh said:

Hi Folks, this will be my first post on here, and regarding my daily runner.

A 2011 1.6 TDI  of ~ 146000 Miles

Now on the whole she's pretty spot on, there are however a few niggles that I cant fathom out. 

If you are rolling with the clutch down (say braking to a stand) it will drop to 1000rpm.

One you have stopped rolling the revs will drop to 800rpm, but the engine judders noticeably as it drops these last 200rpm.

Also, since I had an injector fail, there is a very slight judder at low revs under load, my mechanic doesnt seem to notice it, but I certainly can.

Maybe with nothing that she sat for two years without really turning a wheel.

Was the replacement injector coded in when it was fitted? Not doing this could certainly cause rough running.

 

As for the idle speed variation, it's normal to see that. When the vehicle is still moving the engine keeps the revs higher to reduce the risk of stalling if drive is re-engaged. Once you stop it drops down to its normal idle speed. The juddering probably relates to the injector: you need to check this out before going any further.

I know there was an issue getting the code, but after talking with the manufacturer and getting a code from them my mechanic is adamant that there is no issue there.

Having been back to him, he seems unable to find fault with anything. 

I have been talk g to a lot of people regarding this, someone did suggest I jector refurbishment?

You'll have to forgive my ignorance,  I've grown up working on engines, usually classic patrols though, injectors are a

Still somewhat of a mystery to me.

Certainly when you add computers to the mix!

The required code is etched onto the top of the injector, diagnostics are used to set it on the ECU. It tells the ECU how to adjust operation of the injector so that all the cylinders fire evenly.

5 minutes ago, chimaera said:

The required code is etched onto the top of the injector, diagnostics are used to set it on the ECU. It tells the ECU how to adjust operation of the injector so that all the cylinders fire evenly.

That is what to mechanic expected, it was not the case with the supplied injector.

10 minutes ago, Woosh said:

That is what to mechanic expected, it was not the case with the supplied injector.

That would make me a bit nervous about the provenance of the injector tbh. It might be worth a trip to a diesel injection specialist to see if they can diagnose what's going on.

I am along the same lines of heading to a specialist, I don't take my mechanic as a fool, he does know his stuff, and I know he sources decent parts. If I recall correctly it was Siemens he was in conversation with over the issue. But then a second opinion never hurt

Did he fit a new copper washer under he injector for sealing and did he reuse the HP fuel pipe from rail to injector. These are meant to be 1 fit only and replaced whenever removed. At work (non automotive but engine related) we replace both items when removing injectors 

I'm not 100 % sure on the 1.6, but on the 2.0 the HP lines can be reused.

15 hours ago, chimaera said:

I'm not 100 % sure on the 1.6, but on the 2.0 the HP lines can be reused.

 

That does go against all the advice we have for high pressure diesel systems here in a production environment. 

 

In a prototype / test environment, where competent engineers will be doing the work and understand what failure modes to look for. But in a typical garage then I'd suggest against it. 

 

Over 1000bar fuel rail pressure will act like a water jet and cause serious damage if it let's go. 

 

I'll add the advice I've had is from an FIE supplier, HP pipe supplier and senior design engineers at several automotive OEMs and consultants. 

 

For the sake of the relatively small amount of money they cost it's not worth the risk. 

 

They are designed to yield against the injector fuel inlet to seal. 

18 hours ago, Nathanio said:

Did he fit a new copper washer under he injector for sealing and did he reuse the HP fuel pipe from rail to injector. These are meant to be 1 fit only and replaced whenever removed. At work (non automotive but engine related) we replace both items when removing injectors 

I know he certainly changed the washer, cant say about the HP line. I've a feeling he may not have. I dont doubt him though, he's highly recommended by a close friend who is no stranger to an engine, and the chap trained through VW as I understand it. 

9 hours ago, Nathanio said:

 

That does go against all the advice we have for high pressure diesel systems here in a production environment. 

 

In a prototype / test environment, where competent engineers will be doing the work and understand what failure modes to look for. But in a typical garage then I'd suggest against it. 

 

Over 1000bar fuel rail pressure will act like a water jet and cause serious damage if it let's go. 

 

I'll add the advice I've had is from an FIE supplier, HP pipe supplier and senior design engineers at several automotive OEMs and consultants. 

 

For the sake of the relatively small amount of money they cost it's not worth the risk. 

 

They are designed to yield against the injector fuel inlet to seal. 

I'm going off the Skoda service manual which says they can be reused provided they're not corroded or damaged, tighten the injector end first before tightening the fuel rail end.