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Discussion Starter #1
2004 2.4 JTDM 116000 miles.
I`ve only had this bella for a week now, and it`s the first chance I`ve had to remove the engine cover.
Yikes there is a sticky mess which i presume to be congealed diesel ? it has dried to the consistency of soft road tar. There appears to be no wet residue anywhere, the spots seen in the pic below are dried. The gully on the casting has a 6mm deep well of the stuff.
I wonder if anyone could help to figure out how old this leak might be.
and also what would be the best way to witness the injector pipes at their most pressurised, whilst stationary, in order to see if there`s a leak anywhere.

Thanks a lot.
 

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The injector washer is on the bottom of the injector not where your arrow is pointing at the pipe. A common problem on all makes of diesel engine.The injector and old seal has to be removed. Then the bore and seat need to be cleaned out thoroughly to allow a new washer to seal the injector properly properly. I always try to get the top of the engine clean of the black tarry substance before starting the job. Various chemicals can be used for this but my preferred one is to use domestic oven cleaner. It's made to dissolve thick burnt on grease which is exactly what gathers around the leaky injector.
Sometimes the injector does not give up easily, others it will just pull out.
 

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cheers for the advice.
would it be ok to run the car till next friday when i can get it apart.
It shouldn't hurt it. But obviously there can be no guarantee on that. Personally if I needed the car I would use it. I've seen them run for hundreds of miles with owners blissfully unaware that there is a problem. Sometimes they think the exhaust is blowing but on occasions they carry on till they can't stand the smell any longer. I've seen engines where the injector is totally encased in the tar.

Mercedes are the worst engines for this problem due to the way the injector is held in with a very long6mm bolt.Very often scraps the cylinder head on them. In Merc circles they call it The Black Death.:lol:
 

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Discussion Starter #7
wow. the slow death from black tar. sounds dreadful.
i gotta save her. never thought i`d be using oven cleaner on an engine.
thanks again for all the wise words.
 

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wow. the slow death from black tar. sounds dreadful.
i gotta save her. never thought i`d be using oven cleaner on an engine.
thanks again for all the wise words.
Read up on the Merc problem, you'll be glad you've got an Alfa :thumbs:
Your engine doesn't look bad enough for any serious cleaning as I said. It can't have been blowing for very long.
 

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Oh the joy. I have owned 2 mercedes vitos and had the same problem with both. It is a fairly straightforward fix as long as the injector comes out easily. At least on the alfa they are easy to get to. I found it is better to remove the injector with the engine warm because it will come out easier.

Running it while it is leaking shouldn't cause the car any problems but is potentially unhealthy for you breathing the diesel vapour. Just don't leave it too long because it makes more and more of a mess.
 

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I had the same issue on a Renault Megane DCI. I cleaned the gunk off with carb cleaner. I was surprised how easy the injector came out, and slightly annoyed because I'd been out and bought a slide hammer.
I ended up changing all four seals just so I wouldn't have to do it again in the future.
 

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my engine had this on injector one, then injector seal 4 failed so ended up taken them all out to replace the seals, the garage broke two injector pullers doing it, in the end they used a slide hammer to get them out, 13 hours work and £750 bill, i was so impressed
 

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my engine had this on injector one, then injector seal 4 failed so ended up taken them all out to replace the seals, the garage broke two injector pullers doing it, in the end they used a slide hammer to get them out, 13 hours work and £750 bill, i was so impressed
what a joke......
the injectors are a loose fit the gunk keeps them tight.......
when i removed one of mine i let it soak in coke over night then just wiggled side to side with large spaner at same time as levering up.......it was out in 10 mins
 

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sometimes the seat will need cutting to allow the seal to seat properly. they get pitted with the gasses blowing by
 

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Discussion Starter #14
thanks so much everyone for all the replies, it does help my understanding big time.
google images of 2.4 injector seals brings up so many images I cant decide what i need.

http://www.ebay.co.uk/itm/ALFA-ROMEO-166-2-4-JTD-DIESEL-INJECTOR-SEALS-BOSCH-COMMON-RAIL-INJECTORS-/271044193522

that look right ?
if some kind member could show me the actual injector i`m likely to be extracting would help me no end. i want to be best prepared and armed with the right approach.

Regarding the blowing sound on idle.
I could feel no definative leak whilst proding around the top of the engine,but could hear a big repeating blowing sound on idle. I realize the injector pressure is most likely atomizing the diesel into micro droplets, would an injector leak give a very definate loss in revs to torque ratio, particually in 2nd and 3rd.

replies appreciated
William
 

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Discussion Starter #15
sometimes the seat will need cutting to allow the seal to seat properly. they get pitted with the gasses blowing by
hi mate. thanks for your input.
What you`re describing sounds like a seal with a threaded type locking action, an angular seat that could have worn. is there a reseating tool that they sell?
I am a cnc machinist, i could make such a tool if needed. we could post it around the country to reseat other joints in need.

:)
 

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what a joke......
the injectors are a loose fit the gunk keeps them tight.......
when i removed one of mine i let it soak in coke over night then just wiggled side to side with large spaner at same time as levering up.......it was out in 10 mins
i didn't realise you were such an expert on my car.

Gus at alfatune drew my attention to injector one on my car, he told me it would be very difficult to remove it, however it kept running for another 1.5 years like this before number 4 seal failed, and then it was very difficult to drive

as im doing 70 miles a day i dont have the time or patience to be messing about, so i have to pay, and other people may have to pay
 

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Discussion Starter #18 (Edited)
I`ve had a good result. Managed to fix it.
I was expecting the injector unit to be under pressure but there was nothing when undoing the pipe connection.
Thankfully injector wasn`t overly tight. shifted with a tommy bar.
The evidence of a black burnt line on the injector side of the copper seal told me the
main seal face on the casting was still good.
Rather than attempt to take the injector end off i decided to grind the end face in situ to renew it. Well my mate at work did it on his fancy jig grinder. http://www.stag-brewing.co.uk/Seal Face.MOV
A dial test indicator showed a dip of only one thou on the pitted burnt line, and that was still enough to cause a leak !!

Again i want to thank you all for your help.
cheers :thumbs:
 

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I believe that coating the injectors with ceramic grease before refitting them is a wise move that prevents seizure of the injector in the cylinder head. Got to be worthwhile if they have to be removed because of seal failure.
 

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I'm thinking that the copper washer gives a little over time, and then they start to leak; so should they be re-torqued at intervals? If so, to what torque? Or is this a case where it's better not to fix what isn't broken. Anyone know?
 
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