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+--- Thread: Injector leakage (/showthread.php?tid=7270)
Injector leakage - Boatbuilder - 06-25-2016
Hi, E 320 CDI injector leakage. Have cleaned (machined ) injector seat and seat in cyl head. New Cu gasket and tightened up to spec. Still leakage, a lot actually, hard to start. Have I overlooked something ???
RE: Injector leakage - starynovy - 06-26-2016
Are you positive it leaks by injector seat? When you take it off you should see black burned path in seat.
RE: Injector leakage - Boatbuilder - 06-26-2016
(06-26-2016, 04:56 AM)starynovy Are you positive it leaks by injector seat? When you take it off you should see black burned path in seat.
Yes I am sure. Leakage in the seat. It started with stripped threads in cyl head and injector loose. Drilled and tapped to M8. Normal torque for the original M6 are 7 Nm plus 90 degrees. With M 8 I can tighten more and leakage less,
but not possible to get rid of the leakage. Diesel popping out and hole injector wet.
Will try with softer Cu material in seal washers.
RE: Injector leakage - MartinB - 06-26-2016
I think you need higher gasket
RE: Injector leakage - Boatbuilder - 06-26-2016
(06-26-2016, 08:49 AM)MartinB I think you need higher gasket
Already tried without success.
RE: Injector leakage - Boatbuilder - 07-03-2016
Have tried With gaskets from Honda Accord 2,2 diesel which are considerably
thicker. Still leaking diesel . Somebody who knows about a "Secret stuff" like
gumgum f.example ?
I am fastening the bolt With 3 Nm which are much more than specified.
Spec. 0,7 Nm and 90 degrees.
Hoping for serious hints ? What can be done ??
RE: Injector leakage - barrote - 07-04-2016
ok ,
if is leaking fuel, is not the seat of the injector that is bad... to start with. so forguet that, the only thing that may come out by the seat seal is air press missed with smoke and soot.
the injector has several screws where it can leak due to fatigue. the first one is the nozzle, u can remove the nozzle and check condition of the threads and the nozzle holder cap. beware there is shims and springs and they all must be assembled in the same position. (due neddle fagility) sealing is by face contact so tight force is 50N or more. tke a wrench and tight as much as u can.
the other screw is the solenoid conection, 27mm nut. thats where they are most often leaking. inspect the thing and replace as necessary (same care should be exercised shims and springs are not to be changed)
then u have return lip , usually they loose fuel through return too. when is too much injector is defective change by another one. the return quantity must be compared as per manufacturer.
replacing the head solenoid , must be done with a iqual part number solenoid, take my guess, if u have this problema go in diesel shop and ask the thing to be tested. most probably it needs to be rebuilt . then u have 2 choices , rebuilt or have one in the scrap yard.
be aware all look the same and most probably all fit the head , but for diff engines they have diff specs, so as long as all are the same no problem, but having one or two diff the engine might suffer premature damage.
good luck.
be aware of injector tip depht in the head too.
RE: Injector leakage - Boatbuilder - 07-04-2016
Hi,
Injector have been tested by Bosch and ok prior to the leakage.
I have also tried with a brand new injector and same results.
I really doubt the injector itself are the problem.
Engine runs okey but diesel fuel are popping out from bottom of injector
and I can see and smell and taste diesel.
Also some exhaust gases are coming out together with the diesel.
When the engine runs for a few minutes it start to come out
around the area where the clamp and clamp bolts are .
RE: Injector leakage - barrote - 07-04-2016
well, that is odd, to say the least.
i also seriously dought the injector leaks , but i´ve seen many things....
the injector gasket is just a copper washer, it only seals if the seat (cylinder head aluminium) is properly machined with a special tool for the efect. u can also use machine shop tools as long as u can cut the seat right.
is not necessary to tight too much , just squezze the washer a bit.
just try some water in the injector well, if its chamber pressure leaking u can see bubles, so try again to fix the seat, all clean and that should remedy the situation. if u have a replaceent injector try with the replacement.
good luck
RE: Injector leakage - Boatbuilder - 07-05-2016
Hi,
Will resurface the injector seat again with fine emery paper on a special tool I have made.
Surface should then be with a "mirror " finish , at least better than the surface
obtained with tools which you normally use for cleaning up injector seats.
RE: Injector leakage - barrote - 07-05-2016
hy,
its not the seat surface finish that promotes good sealing , is the surface plane compared to the injector seat, and that must be within 0º tilt. without the special tool or machine shop tools u can´t achieve it, maybe if u are a good and gifted artizan. (and lucky fella)
actually something is going on there , cause this takes 30 min to solve in a MB, and 20 of them is to remove and clean soot.
if u cut too much take in consideration injector well depht, there is several thickness washers , u can even use 2 washers.
good luck
RE: Injector leakage - MartinB - 07-05-2016
You are wrong... spec is 7Nm + 90
I think that was the main fail..