leaking 240 injector - PeachParts Mercedes-Benz Forum

harrygrey382 · #1 07-26-2007, 12:20 PM

Just installed a middle aged 240D in my 115 (straight swap, someone had already done the hard work converting it from a 230/4 to a 240 from a 123).
All running nicely apart from a leaking injector. The fuel looks like it's coming from between the upper and lower half of the injector, not from round the head.
Firsty, will I be damaging the injector by driving it (I need it at the moment)?
Secondly, what could be causing it? I know I've got to take the injector out, and take it apart to really find this, but looking at diesel giant, there doesn't seem to be a gasket between the two so I'm guessing either it's loose or damaged. But I'm getting about 40mpg and performance is right (I assume, never driven one before but going on descriptions, and pulls about as well as a 90hp MKIV Golf) so it can't be that damaged. I'm asking this because I'd like to order anything in before I take it out and apart so it isn't off the road for long.
Thanks

whunter · #2 07-26-2007, 12:47 PM

Quote:

Originally Posted by harrygrey382

Just installed a middle aged 240D in my 115 (straight swap, someone had already done the hard work converting it from a 230/4 to a 240 from a 123).
All running nicely apart from a leaking injector. The fuel looks like it's coming from between the upper and lower half of the injector, not from round the head.
Firsty, will I be damaging the injector by driving it (I need it at the moment)?
Secondly, what could be causing it? I know I've got to take the injector out, and take it apart to really find this, but looking at diesel giant, there doesn't seem to be a gasket between the two so I'm guessing either it's loose or damaged. But I'm getting about 40mpg and performance is right (I assume, never driven one before but going on descriptions, and pulls about as well as a 90hp MKIV Golf) so it can't be that damaged. I'm asking this because I'd like to order anything in before I take it out and apart so it isn't off the road for long.
Thanks

Try re-torquing the injector body first.

Have a great day.

toomany MBZ · #3 07-26-2007, 01:24 PM

Do as whunter mentions, 55 ft. lbs. 27mm=1 1/16 inch deep socket, also check fuel lines, they can leak and it's hard to tell where from. If you do finally take it out, there is a heat shield, washer, what have you, that you will need to replace. Then you can take it to a shop for testing, but if you need the car, try to get a used one in it's place. Remember to change out washers every time you remove, and note their orientation. If you put them in upside down you'll have a leak. The only damage will be lower fuel mileage.

harrygrey382 · #4 07-26-2007, 03:01 PM

yeah ok might as well try them first. Thanks

harrygrey382 · #5 07-28-2007, 03:16 AM

put new return lines on, put a torque wrench on the injector, was at least 55lbs. Still leaking.
What causes a leaking injector. I'm waiting for heatshields to come, but what are the chances of me needing a new injector?

mobetta · #6 07-29-2007, 05:16 PM

when it was disassembled(maybeee by a novice

) it wasn't cleaned well enough, or torqued well enough. also possible that it may need to be re-lapped, like a valve seal. or the the inj. is broken/split at the threads from over tightening, i suppose.

place in vice upside down, so the vice squeezes on the solid part of the injector. use the 27mm to loosen up the 2 halves. remove from vice. disassemble. wax paper works well as a clean, disposable work surface. note the order things come out, if you put it together wrong, they dont work well.

clean the threads real well, and a lil bit of clean diesel or engine oil. re assemble, torquing to 70-80 nm= 60 ft lbs

harrygrey382 · #7 08-08-2007, 11:17 AM

ok still haven't removed it as I thougth it improved (started thining it was hot oil from the rocker cover, replaced the gasket - it wasn't). Still sceptical that it could be leaking from between the injector (the diesel still sits inbetween the two a little, but pools much more down around the head). Could it be a leaking fuel line, and the hot injector body vapourises the fuel as it runs down, thus feeling and looking dry when inspected, but pooling in crevices?

harrygrey382 · #8 08-08-2007, 11:22 AM

see the pics

toomany MBZ · #9 08-08-2007, 07:18 PM

Quote:

Originally Posted by harrygrey382

put new return lines on, put a torque wrench on the injector, was at least 55lbs. Still leaking.
What causes a leaking injector. I'm waiting for heatshields to come, but what are the chances of me needing a new injector? Minimual, replace heat shields, check again.

Good work so far.

DieselAddict · #10 08-08-2007, 08:25 PM

Quote:

Originally Posted by harrygrey382

ok still haven't removed it as I thougth it improved (started thining it was hot oil from the rocker cover, replaced the gasket - it wasn't). Still sceptical that it could be leaking from between the injector (the diesel still sits inbetween the two a little, but pools much more down around the head). Could it be a leaking fuel line, and the hot injector body vapourises the fuel as it runs down, thus feeling and looking dry when inspected, but pooling in crevices?

You need to use a wrench (22 mm I think) to tighten the upper half of the injector. I don't know if you can do it with the injector installed, but it's worth a try. If not, just take the injector out, put it on a clean floor and with a 27 mm deep socket and ratchet in one hand and the 22 mm wrench in the other hand, tighten the injector pretty hard. Or use a vice if you have one. If it still leaks after that, you'll need to disassemble the injector, clean the parts well, then reassemble. But if it's a very minor leak (it doesn't drip on the ground) I wouldn't worry about it.