200Tdi Injector refurb

[Ibex94]

Evening all,

I've just had my fuel pump rebuilt and was told it was full of carp so I decided to pull the injectors to check they were clean and clear.  Having done so I realise that the nozzles are worn and have bought a spare set.  The nozzle retaining nuts take quite a torque to undo but I'm assuming that's a function of the coke that builds up around the nozzle to nut interface and general age.  Can anybody tell me how tight I should torque them back up or do I go with 3 white knuckles and a grunt🤪.

Thanks

Rob

[Mo Murphy]

Morning,

Torque is 20nm for the clamp nut.

Mo

 

[Ibex94]

Thanks Mo, but that's the clamp which retains the injector in the head.  Unfortunately LR didn't consider the injector to be serviceable so there's no information in the manual, Bosch would like you to take them to a service centre so I've not been able to find any torques figures.

[daveturnbull]

Tight's tight. Bust is too tight.

[Mo Murphy]

2 hours ago, Ibex94 said:

Thanks Mo, but that's the clamp which retains the injector in the head.  Unfortunately LR didn't consider the injector to be serviceable so there's no information in the manual, Bosch would like you to take them to a service centre so I've not been able to find any torques figures.

Oops my mistake ! Apologies 😬

When I don't know what the torque should be I undo it with the torque wrench, upping the torque until it undoes. Not super accurate but does give a ball park figure.

Mo

[Ibex94]

2 hours ago, daveturnbull said:

Tight's tight. Bust is too tight.

Love it, do you have an indicator of imminent failure?🤕

[Bowie69]

18 minutes ago, Ibex94 said:

Love it, do you have an indicator of imminent failure?🤕

Creaking.

Of the elbow joints!

Worth noting that the undo torque (assuming not rusted in place) will always be lower than the doing up torque.

 

[Ibex94]

34 minutes ago, Bowie69 said:

Creaking.

Of the elbow joints!

Worth noting that the undo torque (assuming not rusted in place) will always be lower than the doing up torque.

 

I think this may be an exception, they were proper friction tight to undo - I think carbon and 30 years didn't help.  They are a proper fine thread so I wouldn't expect such a high torque to do them back up.  My sphincter twitchometer would be having convulsions😂

[Eightpot]

I took mine to bits and cleaned them in an ultrasonic bath.  I did the nozzles up to a moderate heft on the wrench rather than a thread stripping vein bulging dilithium crystal wrecking monster torque

And they haven't fell off yet 🙂

[reb78]

7 hours ago, Eightpot said:

I took mine to bits and cleaned them in an ultrasonic bath.  I did the nozzles up to a moderate heft on the wrench rather than a thread stripping vein bulging dilithium crystal wrecking monster torque

And they haven't fell off yet 🙂

Serious question... can they fall off? Done up nice and tight and the injector clamped in place and as long as they dont leak, they cant com apart can they? 

[monkie]

Willing to stand corrected but I don't think so Richard. The bottom part that retains the nozzle and has to be tight enough to keep high pressure diesel in and dirt out. When fixed in the cylinder head I can't see how it could come undone as it is held down between port in the head and the injector hold down clamp. I would imagine that if you really didn't tighten it up to hold the nozzle correctly then the injector wouldn't work properly and the engine would run like a bag of spanners as soon as you started it. 

[hurbie]

what brand nozzle's did u use , i asume bosch ? do you have a partnumber for those ?

[Ibex94]

1 hour ago, hurbie said:

what brand nozzle's did u use , i asume bosch ? do you have a partnumber for those ?

Bosch, found supply on ebay - https://www.ebay.co.uk/itm/LAND-ROVER-200-TDI-NEW-BOSCH-INJECTOR-NOZZLES-SET-OF-4-DSLA145P208-0433175017/274456947691?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Part number on mine is DSLA 145 P 208 its etched on the barrel of the injector nozzle.

[Ibex94]

2 hours ago, monkie said:

Willing to stand corrected but I don't think so Richard. The bottom part that retains the nozzle and has to be tight enough to keep high pressure diesel in and dirt out. When fixed in the cylinder head I can't see how it could come undone as it is held down between port in the head and the injector hold down clamp. I would imagine that if you really didn't tighten it up to hold the nozzle correctly then the injector wouldn't work properly and the engine would run like a bag of spanners as soon as you started it. 

You want the torque to be high enough that the preload on the assembly is greater than the force exerted by the pressure.  Its a really fine thread so they shouldn't need to be ridiculously tight but it took some force to undo them as there was coke in the annulus between the nozzle and the securing nut and some light corrosion at the end of the threads.

They are unlikely to come undone once installed as fixing is pretty positive its more of a fatigue issue imho

[Ibex94]

10 hours ago, Eightpot said:

I took mine to bits and cleaned them in an ultrasonic bath.  I did the nozzles up to a moderate heft on the wrench rather than a thread stripping vein bulging dilithium crystal wrecking monster torque

And they haven't fell off yet 🙂

So three white knuckles then😀