Mystery Leak
06-10-2016, 02:22 PM
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W123 230E, W202 220 CDI, W903 313 LWB
Mystery Leak
Hi, I've been battling a mystery diesel leak on my OM611 for the past two weeks.
The diesel is pooling in the valve cover around the injectors and can be 20mm+ deep after a 2hr drive. It's clean diesel too, no apparent contamination. I've replaced the injector washer on No. 1 cylinder twice, (everything cleaned and the seat reground once), check the injector for damage or cracks, checked the fuel feed pipe is seating properly, tested the engine at varying revs for leaks at the fuel pipes/injector tops/anywhere else, and changed the leak off connector on No. 1 for a brass one.
At idle and moderate revs there's no apparent leak, but obviously under load or at higher revs it leaks because when I arrive after driving there's diesel pooled in all injector wells.
Please if you have any experience or suggestions I'd appreciate your input as any searches on the topic of diesel leaks on the CDI lead to posts about black death and this isn't that so I'm stumped.
Many thanks
The diesel is pooling in the valve cover around the injectors and can be 20mm+ deep after a 2hr drive. It's clean diesel too, no apparent contamination. I've replaced the injector washer on No. 1 cylinder twice, (everything cleaned and the seat reground once), check the injector for damage or cracks, checked the fuel feed pipe is seating properly, tested the engine at varying revs for leaks at the fuel pipes/injector tops/anywhere else, and changed the leak off connector on No. 1 for a brass one.
At idle and moderate revs there's no apparent leak, but obviously under load or at higher revs it leaks because when I arrive after driving there's diesel pooled in all injector wells.
Please if you have any experience or suggestions I'd appreciate your input as any searches on the topic of diesel leaks on the CDI lead to posts about black death and this isn't that so I'm stumped.
Many thanks
06-10-2016, 02:47 PM
#2
Out Of Control!!
Your best bet is to first clean up the existing fuel pools--then expose all the high and low pressure\return lines-----run the engine---wait and observe------where is it leaking??
Locate and fix the leak and get on with your life!!
Locate and fix the leak and get on with your life!!
06-10-2016, 02:50 PM
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W123 230E, W202 220 CDI, W903 313 LWB
Hi Plutoe, and thanks.
Yes I've done this four times now - cleaned out the diesel, let the car run, watched, waited, revved etc. No obvious signs. The fourth time it was under the supervision of a Bosch technician and it was he who changed the leak off union for a new brass one. He rand the car for a half hour to watch and observe and all looked well. An hours drive later and on a quick pit stop to check and the diesel was back again!
Yes I've done this four times now - cleaned out the diesel, let the car run, watched, waited, revved etc. No obvious signs. The fourth time it was under the supervision of a Bosch technician and it was he who changed the leak off union for a new brass one. He rand the car for a half hour to watch and observe and all looked well. An hours drive later and on a quick pit stop to check and the diesel was back again!
06-12-2016, 07:42 AM
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mb, saab, acura, dodge
You could have a hairline crack in one of the lines. Take some paper towels and wrap each connection, drive car for short periods. Open hood and see if any are wet.
