Unit Injector Torques

[passing]

Hi
Has anyone any experience of tightening the above ?
Haynes gives 12NM first followed by 270 degrees and I am advised to use new bolts. My engine code is ATJ
My garage tell me that they are worried tighteing by this anmount and have sheared the injector clamp bolts on a previous VW.

But as I had an injector come loose I want to make sure it is right this time.

Any experiences - good or bad would be appreciated

[martin1810]

The figures are correct and you use new bolts. That's just how it is done.

[passing]

thanks Martin

The reason for re-doing it is that the head rebuilder did not use new bolts and so that is the reason I am assuming for one coming loose now.

I want it done right this time ! But I am also wary of the garage disowning responsibility if it does shear.

[Crasher]

When an injector comes loose, it always wrecks the head in my experience. Get them to check these areas.

[passing]

Thanks Crasher.
I feared that it might be the case.
The car covered 1500miles between rebuild and stopping and so I hope that I may be lucky.

I have just got the car back from the engineers with the injector removed and the insert in place. I can see some scuffing on the body of the injector where it has been sliding up and down against the locations you indicated. The formerly dark colour of the surface is scuffed away to bright metal.

The O-rings are as expected damaged too but the retaining shoulders for the o-rings seem to be OK.

I will check the locations you indicated for ovality - but I don't have any dimensions for reference to check for wear. Awaiting a copy of elsawin and so if it is in there any references are welcome.

The heat shield and retaining ring seems to be present on the injector still and so have not disintegrated and fallen into the cylinder as I wondered.

Otherwise I plan to look at the injector business end with a magnifying glass though I don't really know what I am looking for.

I also need to decide whether to extract the other three injectors and re-seal them as the engineer saved a few pounds there too by not fitting ne seals.

Also trying to decide how far to go in checking for swarf in the sump. I agreed with the garage to flsuh through with 10l of fresh oil. Maybe once clean at standstill and once running with a flushing additive. I really would llike to avoid removing and cleaning the sump out by hand which at the moment is the planned route to be sure nothing is in the suction strainer.

Now have to wait two weeks as I am away until I can get the car into a garage and so have time to make up my mind.

[Crasher]

There are no dimensions, if the area is any more that rubbed and you can feel a grove, the head is scrap. I have had to dump numerous heads because of this but thankfully they are now available aftermarket for around half the £1k of a genuine bare head.

[passing]

I'll stick the MK1 digit down the hole and see what I can find then - thanks crasher.

Mind you when I had the initial bent valve problem I enquired at the ******** and was quoted £2000 for a bare head plus vat. So if you aregetting them for £500 it is an even bigger bargain.

[Crasher]

Naughty, using the S word! Anyway, I will forgive you this once. They are not thieves but they are incompetent. A new bare head is £950 genuine inc. VAT and a full exchange recon head completely built up with cam, valves, injectors, rockers etc ready to fit is a stupefying £2500 inc. VAT which is around £2K plus VAT so the idiots quoted you on a full head. I have used brand new non genuine castings that are around £600 and I have been very happy with them but they are completely bare.

[passing]

stupefying indeed on a car that is worth £3k - £3.5k. I won't (yet) worry the garage who I am holding responsible.

Yes I guess that is a more accurate assessment of some of their abilities and so I gracefully withdraw the comment.

My nearest VW dealer lost a sale as a result of refusing to discuss this particuar problem and instead insisting that I recover the car 30 miles each way so that they could charge me £71+vat to look at it and tell me what I had just told them. That was a pre-condition for them to give me an estimate to fix it.

What they did not know was the wife was interested in a Tiguan at the time.
That was quickly swapped for the Honda CR-V.

Luckily the independent saw sense (or the potential court case) and started to play ball though he still has to get hold of the machine shop or some part of their anatomy in case this ends up as you suspect.

[passing]

I have been away for the last two weeks and so this is the first time I was able to look at the injector socket.
I can't see any damage to the ridges in the socket. I can't feel any grooves either around the periphery or in line with the hole.
Have not been able to try the injector back in the hole as I am awaiting the seals.
Hoping I have got away without writing off the head !