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Coming home yesterday I started to smell diesel at the corner of my street. Went about 1/10 of a mile into the garage and got out to see a stream of fuel leaking from the truck. Threw a drain pan under it and a bunch of oil dry.
This morning I took the splash shields off (they had about another quart of diesel in them) to start to look for the leak. I thought it was going to be the fuel lines on the drivers side as I just replaced the motor mounts (last week and 500 miles ago) and had to work the drivers one past them and figured I stressed it enough to split it maybe. But that's not where it's coming from.
GIF below shows the rate it coming out, it's not just a drip!
I looked at the fuel filter area also and it's dry. I can't see anything from the top side that's getting wet. Pretty much everything under the truck is wet. It looks to be the back of the motor.
You can't see anything from the bottom except it's running all over the place.
I tore down the intakes and pulled the fuel filter to see if it was from there - all good.
Since I had the air boxes off I pulled the foam sound insulation from around the injectors and found fuel residue. Then looking closer I saw a "Leak Oil Line" that had popped off It was drivers side closest to the firewall. I put it back on but it would just lift back off. I didn't think that was right but to confirm that was the leak I put it back on and turned on the ignition and had fuel spewing everywhere.
Looked it up :
"The leak oil line (2) must audibly clip in
for injector and latch circlip (1) on connection fitting for injector and the
circlip (1) press down all the way (arrow) in
order to avoid the leak oil line (2) springing
out."
I couldn't hear or feel the click the manual says you should have but pushed down the locking ring and it did lock on. Pulled the locking ring up and this time it had some resistance to come off and the next time I put it on I heard the click.
Then I checked the other connectors and 4 or the 5 remaining ones didn't have the clips locked down!!!
I locked them all down and turned the ignition on and no leaks
It's like a heat index of 105 here today so I called it a day and will put everything back together tonight when (if) it cools off.
But it got me thinking (after looking at testing injectors) should there be that much pressure/flow there? Am I good or does this indicate that I have a bad injector and popping that off is just a indication of it being bad? I haven't started it up yet so I haven't actually pressurized the rail fully (I don't think it does until the engine starts).
Different car same issue just got my car back 2013 GLK250 diesel. Had a diesel leak dealer found it to be a pin hole leak (rust) at the fuel filter. I got the car a year ago and they fully inspected it. Just recently serviced it This might be a more widespread issue.
I see this post is a month old, but yes, you will hear an audible click when you pull the fitting up to snap it in place. It's made of plastic and it's right there on the valve cover so you know it gets hot. The good news is that they are very easy to replace.
Originally Posted by rosenhauer
You can't see anything from the bottom except it's running all over the place.
I tore down the intakes and pulled the fuel filter to see if it was from there - all good.
Since I had the air boxes off I pulled the foam sound insulation from around the injectors and found fuel residue. Then looking closer I saw a "Leak Oil Line" that had popped off It was drivers side closest to the firewall. I put it back on but it would just lift back off. I didn't think that was right but to confirm that was the leak I put it back on and turned on the ignition and had fuel spewing everywhere.
Looked it up :
"The leak oil line (2) must audibly clip in
for injector and latch circlip (1) on connection fitting for injector and the
circlip (1) press down all the way (arrow) in
order to avoid the leak oil line (2) springing
out."
I couldn't hear or feel the click the manual says you should have but pushed down the locking ring and it did lock on. Pulled the locking ring up and this time it had some resistance to come off and the next time I put it on I heard the click.
Then I checked the other connectors and 4 or the 5 remaining ones didn't have the clips locked down!!!
I locked them all down and turned the ignition on and no leaks
It's like a heat index of 105 here today so I called it a day and will put everything back together tonight when (if) it cools off.
But it got me thinking (after looking at testing injectors) should there be that much pressure/flow there? Am I good or does this indicate that I have a bad injector and popping that off is just a indication of it being bad? I haven't started it up yet so I haven't actually pressurized the rail fully (I don't think it does until the engine starts).
Arrg, I think this is going on. Unfortunately I am out of town. I accelerated at a light to get in the turn lane at next light. I felt like I hit a rev limiter with fuel cut off. I tried accelerating again and felt the same. When I pulled over gas was pouring from under vehicle. I drove slowly about 5 min to a Mercedes dealership and parked it last night.
I had a slow leak around one of the injectors. A few weeks ago my mechanic tried tightening them while in the shop. He probably should have gone ahead and changed the seals at that time. But he was I think more focused on the alt/starter/ AC. ☹️
Is is it a major or expensive job at dealership to change the seals? Wondering if just let them have this one or get to my Indy.
OK, it is the return line. Well, I just replaced one injector, new seal, new return fuel line o-ring, etc.. It is not super hard, it takes a little time and few special tools. I am about to post my experience and steps. I am about to replace one more injector next week.
Well bit more involved. Glad it is not at the dealer. I was let go too long by last mechanic and should have been addressed but I don't think he was as familiar with these engines as much. I have a current mechanic. Will post what is found after injector out. Thinks the seal may have melted allowing all the compression out.
This is typical, nothing is melted, all it takes is a small leak past the washer/seal and due to the high pressure over time it will do that and it does not take that-that long. Many mechanics, especially the Dealer will say "new injector needed" . Unless you test the injector and it shows it is bad, re-use it!..., chances are that it is good. They are very tough designed to resist cylinder explosion, vibration ,etc, some carbon around the body does not do much unless the connectors are melted. Good luck!
. Soak it. One trick I just read on the web is to loosen the injector bolt then run the engine, this may dislodge it a little , hence easier to remove. !!!slight loosening of the bolt!!!... I will try that on my last injector as it looks similar to yours, maybe 25% better on the carb buildup on top.
Thanks for the suggestions. I have the Honda s als on order. The mechanic I am using seems insistent on a new injector but will see. He seems very knowledgeable and works on a lot of sprinters. Going with the flow. Anything better then merceds.
I will post follow ups. But plan is to remove injector and make sure no damage on head after the seal is removed. The clip had melted on the connector. He plans to remove and reipin. Then the plan is to reseal all injectors with new Honda seals as well as bolts and clips
You can't see anything from the bottom except it's running all over the place.
I tore down the intakes and pulled the fuel filter to see if it was from there - all good.
Since I had the air boxes off I pulled the foam sound insulation from around the injectors and found fuel residue. Then looking closer I saw a "Leak Oil Line" that had popped off It was drivers side closest to the firewall. I put it back on but it would just lift back off. I didn't think that was right but to confirm that was the leak I put it back on and turned on the ignition and had fuel spewing everywhere.
Looked it up :
"The leak oil line (2) must audibly clip in
for injector and latch circlip (1) on connection fitting for injector and the
circlip (1) press down all the way (arrow) in
order to avoid the leak oil line (2) springing
out."
I couldn't hear or feel the click the manual says you should have but pushed down the locking ring and it did lock on. Pulled the locking ring up and this time it had some resistance to come off and the next time I put it on I heard the click.
Then I checked the other connectors and 4 or the 5 remaining ones didn't have the clips locked down!!!
I locked them all down and turned the ignition on and no leaks
It's like a heat index of 105 here today so I called it a day and will put everything back together tonight when (if) it cools off.
But it got me thinking (after looking at testing injectors) should there be that much pressure/flow there? Am I good or does this indicate that I have a bad injector and popping that off is just a indication of it being bad? I haven't started it up yet so I haven't actually pressurized the rail fully (I don't think it does until the engine starts).
Any chance you could post pics of the lines in question?
I did the same this weekend on my R class, over enthusiastic acceleration followed by the same symptoms as you. Mines at the garage but still waiting on the verdict did you get yours sorted?
Originally Posted by smiledr996s
Arrg, I think this is going on. Unfortunately I am out of town. I accelerated at a light to get in the turn lane at next light. I felt like I hit a rev limiter with fuel cut off. I tried accelerating again and felt the same. When I pulled over gas was pouring from under vehicle. I drove slowly about 5 min to a Mercedes dealership and parked it last night.
I had a slow leak around one of the injectors. A few weeks ago my mechanic tried tightening them while in the shop. He probably should have gone ahead and changed the seals at that time. But he was I think more focused on the alt/starter/ AC. ☹️
Is is it a major or expensive job at dealership to change the seals? Wondering if just let them have this one or get to my Indy.
Hope you get it sorted, my leak is coming between the cylinder heads at the back of the engine so no idea what’s wrong, hoping a pipe has popped out under pressure rather than anything else. Strange thing was car still works and drives and no lack of performance just leaking diesel
Mine seemed to drive fun unless modest acceleration, then it felt like I hit a rev limiter. Hopefully no issues.
Mechanic did find a mass air fault, not sure if it was old or associated. Up until then it ran great.
decided to have injectors tested for piece of mind. The affected injector tested ok but had some melting around connector so replacing. Will have other injectors tested tomorrow. At least will know that they all have correct flow. Apparently the machine flushes them out initially as a process. Would be nice to know flow rate and spray before and after. I had the injectors on my 944 turbo tested as such.
Should hopefully have have an update later this week.
Last edited by smiledr996s; 09-26-2017 at 08:24 PM.
07-19-2017, 09:57 AM
It was drivers side closest to the firewall. I put it back on but it would just lift back off. I didn't think that was right but to confirm that was the leak I put it back on and turned on the ignition and had fuel spewing everywhere. 
