Leak near injectors - '85 300D T - PeachParts Mercedes-Benz Forum

athensbenz · #1 10-04-2004, 12:20 PM

I noticed that a bit of diesel fuel is leaking near the injectors. Fairly confident the return fuel lines are not to blame. Should I pull the injector and check the "crush washer"? Anyone with a similar experience? Thanks in advance.

Hatterasguy · #2 10-04-2004, 12:44 PM

A diesel leak up their is either the return lines or you hard pressure lines. You would know if one of the pressure lines was leaking the car would run like crap. Check your return lines again I bet their the problem. My car did the same thing, I thought fuel was leaking up around the injector it turned out a return line was leaking.

trontek · #3 10-04-2004, 01:30 PM

where th' tang of th' prechamber orients in th' head so's to allow us to get th' glo plug through there. Th' heat shield(that folks are calling a crush washer - & maybe it is but I don't think so) had carbon gumming up about half th' circumference where th' injector seats down into said shield. When th' injectors are tightened down, they are sitting on top of th' hard carbon and fuel leaks thru th' gap and up thru th' threads of th' collar that holds th' prechamber in. I cleaned up some from an '83 and installed them - no more leak.

Noticed th' hole in th' '83 shields was smaller than th' '77 but things seem ok when running. If anyone knows any reason not to leave them in there - holler back....

Glow plugs work a whole lot better if you hook th' resistors up correctly! If you hook every thing up on th' outside of th' insulators, th' engine will not start....

Jim

JimmyL · #4 10-04-2004, 02:27 PM

The...

#5 10-04-2004, 02:53 PM

If you pull the injector and replace the seal, DO NOT overtighten it. Check the book, but I believe the torque spec is 32 lbs. Always use a torque wrench.

braverichard · #6 12-03-2004, 01:07 AM

Just noticed yesterday after driving on the highway for 25 minutes that a little bit of smoke was coming out of my hood after I arrived at my destination. I opened the hood and noticed that two of my injectors were wet. While running, one of them actually looks like it was leaking. There were some hoses on the injectors which were all wet (I guess they are the return lines some people here are referring to). I guess I'll have to start by replacing them. I wouldn't expect my injectors to start giving in at such "low" mileage - 156,561miles (I've read about people with over 300,000 miles on their original injectors).

Anything else I should know?

djugurba · #7 12-03-2004, 02:31 AM

its your return lines. easy DIY job.

TonyFromWestOz · #8 12-03-2004, 09:18 AM

Quote:

Originally Posted by trontek

where th' tang of th' prechamber orients in th' head so's to allow us to get th' glo plug through there. Th' heat shield(that folks are calling a crush washer - & maybe it is but I don't think so) had carbon gumming up about half th' circumference where th' injector seats down into said shield. When th' injectors are tightened down, they are sitting on top of th' hard carbon and fuel leaks thru th' gap and up thru th' threads of th' collar that holds th' prechamber in. I cleaned up some from an '83 and installed them - no more leak.

Noticed th' hole in th' '83 shields was smaller than th' '77 but things seem ok when running. If anyone knows any reason not to leave them in there - holler back....

Glow plugs work a whole lot better if you hook th' resistors up correctly! If you hook every thing up on th' outside of th' insulators, th' engine will not start....

Jim

It is interesting that the poster of this used exactly the same number of keystrokes as he would have if he used the word "the", not his abbreviation "th'"

braverichard · #9 12-03-2004, 09:34 AM

HA HA HA Good observation!!

dannym · #10 12-03-2004, 09:46 AM

When I had this problem I had to replace the injector.
The leak was coming from the threads in the middle of the injector where they screw together.
I tried to seal it but it didn't work. Replacing it was super easy anyway.

Danny

braverichard · #11 12-03-2004, 10:04 AM

Well I sure hope I don't have to replace the two injectors with wetness in the areas immediately near them. I'll start with the hoses first. A cheap, logical first step in the troubleshooting process.

braverichard · #12 12-04-2004, 07:13 PM

It was the fuel return lines. In fact, most of the wetness was always around injectors #2 and #4. I replaced all the return lines connected to injector #4, cleaned it up thoroughly, drove the car around town for about an hour running errands, got back home and saw it was still as dry as it was before I took off. So that's the solution! As preventative maintenance, I will change ALL the return lines. In fact is amazing, after I pulled off the lines I replaced, I compared them to the new ones and they were just worn out. The plastic inside them was stretched quite a lot. I'm glad the problem wasn't related to my injectors.

martyg · #13 12-15-2004, 03:01 PM

Is there a trick to replacing the line?
One side of the hose is off, the other side won't come off.
Does it twist, pull, or what?
Thanks

braverichard · #14 12-15-2004, 03:33 PM

I found it a bit frustrating doing it. I had to use a very small set of pliers to hold onto the fuel line while gently twisting it around as I pulled it upwards and then out. Takes some patience. Sometimes I didn't have that patience and accidentally broke some of the lines, then I had to use a small knife and cut the part that is stuck on the injector to pieces in order to remove it.

JamesStein · #15 12-15-2004, 04:11 PM

Be very carefull if you have to cut. You don't want to accidently scratch the nipple. Scratch it bad enough it will leak.