Northwards Posted June 19 Share Posted June 19 Hi folks, I was replacing the spill/leak off rail the other day and noticed this discolouration around the injector - 300Tdi. This one can also have a "sheen" on it which the others don't, looking a bit shiny after a run. I've done lots on the car over the years, but never done anything with these, putting them in the 'too technical' bracket. Does this point to a leaky injector? If so what needs done and is it particularly tricky? I'd look at my WSM but I'm away from home for a bit. Thanks Quote Link to comment Share on other sites More sharing options...
miketomcat Posted June 19 Share Posted June 19 It does look like it. Easy fix providing it isn't stuck (I suspect it isn't), remove pipes, undo clamp nut, a little twist side to side and it should lift out. Retrieve the copper washer and replace it, reassemble. Torque it up and check for leaks when running. You may need to tighten a little more or loosen and re tighten to get it to seal. Mike 1 Quote Link to comment Share on other sites More sharing options...
Northwards Posted June 25 Author Share Posted June 25 Hi Mike, Thanks very much for your reply - and sorry I haven't said so till now. Just been a mental few days. Injector is very definitely leaking - popped the bonnet after a run yesterday and it's clearly wet. Been doing a bit of googling and I can't actually say I'm looking forward to this. On the plus side, it's only 2 or 3 years since the engine was rebuilt so I shouldn't be dealing with 20 years of soot build-up. Quote Link to comment Share on other sites More sharing options...
markyboy Posted June 26 Share Posted June 26 If it's leaking fuel, it could be the injector pipe union or leak-off leaking? Quote Link to comment Share on other sites More sharing options...
Snagger Posted June 26 Share Posted June 26 It could be a worn injector pipe, the flare being grooved, in which case it’ll never seal up, but it could just be a slightly loose union that needs tightening. I suspect, though, that it is the leak off Union leaking, quite possibly because of Britpart washers that pretend to be copper but are actually steel with a thin copper plating - they are too hard and frequently leak. Undo the injector feed pipe and check the flare or bulb for a groove or distortion, and remove the copper washers and check them with a magnet. I think the cause will become self apparent. Quote Link to comment Share on other sites More sharing options...
Northwards Posted June 27 Author Share Posted June 27 More food for thought.... thank you. As I said, I replaced the leak off/spill rail last week or so. The last one only lasted about two years, so this time I went for something 'bling'... just because. It came with new copper washers. But in any event this leakiness pre-dates that job by quite a while. I just hadn't noticed this staining/leaking because normally there's an acoustic cover on top of the engine, and one of the lead/padding engine blankets on top of that. A leaking pipe union - that's a distinct possibility now that I think of it. When I popped the bonnet after my last run the top of the injector was pretty wet - which I suppose I wouldn't expect if it was leaking from the injector/head washer? If I replace this, is there anything complicated involved, or just remove the old/refit the new? I presume they come with the right flares etc? What's the story at the fuel pump end? Thanks! Quote Link to comment Share on other sites More sharing options...
TSD Posted June 27 Share Posted June 27 If it was leaking from the seat washer, I'd expect it to be black and sooty from all the combustion gases. (Unless it's really bad, but then you'd have a massive misfire). Often you can hear it, and feel it if you hover your hand over the injector when idling. Any time I've had the fuel pipe weeping, it left a clear bead of diesel in the groove between the top nut and the pipe, so quite easy to spot if you dry everything off first. I'd be looking for a leak from the spill rail union as the most likely suspect. The other place I imagine it *could* leak, though I've never seen it happen, is if the injector body has unscrewed from the nozzle and not done back up tight? I've seen injector bodies unscrew if they put up a fight when being removed - I think I've got one doing that in my spare engine at the moment, but I haven't got round to checking if 6 months bathed in ATF has helped at all 1 Quote Link to comment Share on other sites More sharing options...
Daan Posted June 28 Share Posted June 28 When you mention a leaking injector, my immediate thought is an injector leaking fuel in the combustion chamber without it actually being activated by pump pressure. That is what I thought you are referring to, and the discoloring is the result of the head running hot in this area. This can happen if your injectors are decidedly secondhand. Not sure how to spot this, but it will be accompanied by black smoke of unburnt fuel. Quote Link to comment Share on other sites More sharing options...
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