E320 CDi Injector seal replacement

[dynasty888]

Hi Guys

My CDi's been giving me the chuffing noise under the bonnet so having read a few other threads, decided to change the copper injector seals on the 3 that was leaking. I got the injectors out OK but replacing it with one seal did not cure the leak but putting two seals in did. However, the exhaust is now blowing black smoke which suggest the fuel mixture is too rich. A ride in the countryside and a few boot to the accelerator did not clear the black smoke. Will the extra seal cause it to burn rich?

Why does one seal not seal the injector if one came out? Should I be using any injector sealant?

Also when the injectors were out, there was some deposit on the tip of the injector which I used a wire brush to clean up. How do I check the injector is not blocked or knackered.

Any advice muchly appreciated.


Regards


Wills

 

[greyboy]

I had my E320 CDi serviced at "Prestige Car Service" recently. My No 1 injector was leaking and this was fixed at the same time. There is a kit to clean up and recut the seat so the new seal will work properly. Yours probably needs this doing. Also, the end of the injector is part of a precision component which should not be cleaned like a spark plug. Maybe dirt has been forced inside which is causing it to stick open, should be ok after an ultrasonic clean, or whatever they use these days.

 

[dynasty888]

Thanks greyboy.

I've seen this tool on www.uniteddiesel.co.uk so might have to purchase one to sort them out. I thought the injector only opens when a current is applied to it?

 

[BENZ_O]

I had my E320 CDi serviced at "Prestige Car Service" recently. My No 1 injector was leaking and this was fixed at the same time. There is a kit to clean up and recut the seat so the new seal will work properly. Yours probably needs this doing. Also, the end of the injector is part of a precision component which should not be cleaned like a spark plug. Maybe dirt has been forced inside which is causing it to stick open, should be ok after an ultrasonic clean, or whatever they use these days.

HI, May i know how muich u paid for that?? i've got the same problem and mine no1 inj leaking too. I'm strugglin' to find good mechanics but i've seen prestige car garage 1 mile away from my house but im hesitatin' if to go there.

Thanks

 

[jaymanek]

There is only one way to do this properly..

the injector has to be removed with the correct tools..
Then the seat has to be re cut and the bores have to be cleaned..
A new seal and a new retaining stretch bolt and cant go wrong!

 

[big john]

new bolts a must and new clamps to and a recut mb sell an kit to to change the fuel return valve 5 pounds a peice do not over tighten the bolts as the will strip and get a thread cleaner down there to clean the thread holes out

 

[dynasty888]

Hi Benz O

I did it myself in the end. Make sure you have a long reach torx bit set, they're quite cheap on the internet. The seat cutter is not cheap though at £70 and I was fortunate to be able to borrow a set. Garages charge around £40 for each so 6 will set you back £240 which makes £100 tool investment not so bad. You'll also need some injector grease, about £8 for a small tube, new seals and bolts from mercedes(get a couple more than you need in case you need to re-seat any).

You release the bolt from the injector. Turn it slowly and they will come out. Chuck the bolts away. Remove the injector clamp. I did not replace them but scrubbed them clean and fitted them back in. Remove the flexi pipe connected to the top of the injector(use a small flat screwdriver to prise the connector out) and the solid pipe connected to the common rail.

If your injector's gunked up, you'll need to soak it over night with diesel or coke. Get a flat tip screwdriver and scratch off the gunk.
You'll need a pair of locking vice grips to lock around the injector and wiggle it backwards and forward whilst applying an upward pulling force for a bit to get them out. My first one took half an hour of wiggling before it came out. Make sure kids are not around and Missus and neighbours out of earshot as you be swearing a lot. Trust me, it comes out quick when you swear at it. When you apply the vice grips to the injector, use a hammer to knock the handle of the grips backwards and forwards a few time, then you should be good to wiggle away. The vice grip should lock on at around 45 degrees to the injector with the handles stick up in the air at 45 degrees. Make sure you clamp the injector body and not the hexagonal nut holding the solenoid to the injector. If you remove the solenoid by accident, you should find a spring and shim that might fall out. If they do, then stick them back in and tighten the nut back up and re-apply the vice grips to the base of the injector.

When the injector's out, the seat could be either be on the end of the injector or might fall back into the injector hole. Fish it out if it is inside the hole. I cleaned the injector, shove it back in and the seal came out with it. Clean up the gunk around the injector and hole. When you've done cleaning, use the seat cutter and stick it into the injector hole and turn it a couple of times clockwise. Clean out the hole with compressed air or I used my vac and a length of garden hose taped to the end and sucked all the crap out. I used a one led mini torch light to peer down the hole to check whether it's clean or not. Also clean out the bolt threads as liquid inside the bolt holt cannot escape and as you turn the bolt back it, it will strip the threads as the liquid inside the bolt hole cannot be compressed. I stripped my first injector threads and nearly died with shock when I turned the bolt and it was spinning and not gripping but luckily I repaired the threads using a heli-coil(google it).

Make sure you stick some grease around the injector so it doesn't seize up in case you need to remove it later. Chuck everything back together and torque up properly.

Mine's a straight six engine block so the back one was a pain to get out but accessible once you shove the bonnet upright. Have fun doing it and let us know when you've done it.

Wills

 

[compress ignite]

Excellent Tutorial !

I've only one suggestion(for Boogered Threads,Not the Injector Aperture)...Timeserts.

http://www.timesert.com/html/install.html#1

++ TIME-SERT Metric Kits ++ thread repair kits and inserts repair stripped threads damaged threads repaired threads threaded inserts for metal thread inserts for metal aluminum inserts threaded inserts for aluminum

 

[bouzirouge]

what a great post. thank you very much. a days work and my 320 is back on form, change out of 15euro for the parts too. thanks again. saved a whole lot of grief.