fuel leak on cold start

bobiz

New member
Hi guys, i have 2003 sprinter ...since the weather got cold i notices that the fuel started to drip from the intake manifold area toward the firewall its impossible to see where exactly the leak is coming from when i start it in the morning to warm it up after about a minute its starts to drip badly so i go under the van with a flash light and see that the leak runs down the manifold ...what there exactly ? when i stick my hand trough the top of the engine i can feel the wet at the end of the fuel bar or what ever u call it i meant the tube that has all the lines that run from it to the injectors and at the end there's some kind of small plastek house attached to it ...to me looks like the fuel return line and thats what im thinking the leak is form .but to get to it looks like the whole manifold have to be removed.....correct me guys on this one
 

NelsonSprinter

Former Nelson BC Sprinter
That part is the fuel rail pressure regulator , can be removed without engine removal with a 1" long 1/4" hex socket or eTorx , and there is the $12 seal kit from the dealer.
https://sprinter-source.com/forums/showthread.php?t=29457&highlight=fuel+pressure+regulator

I would check under the black engine cover that it isn't the fuel return line leaking down onto it, since it may have come lose off an injector or at a connection, because that much fuel out of the regulator could prevent a start from insufficent pressure, but a leak from the fuel return like may not prevent a start. It is also called the fuel rail's pressure solenoid if you do a search
 
Last edited:

surlyoldbill

New member
If it only leaks while it's cold, and the leak stops once the engine warms up, it MIGHT be the high pressure fuel pump seals. Mine did that last year. Mine dripped right down on to the serpentine belt, your's sounds different. Fuel rail solenoid is on the firewall end, and those have a set of o-rings that are known to go bad, but that causes a drop in rail pressure, not a leak as far as I know. Other people have found split or cracked fuel return lines between the injectors and the fuel filter.
 

bobiz

New member
about that i took the black cover off its super clean no traces of black death at all...how will i see what needed to be taken off i looked at about taking the manifold off looks like it will be impossible to do that with out engine removal...does anyone have any pictures of that fuel rail ? so i can see what need to be done
 

312d

New member
manifold is easy to take out, you will need a external torx E8 or E10, preferably deep socket, also an 2 or 3" extension in 1/4" or 3/8" drive.
 

pacman_34

Member
See the thread that NelsonSprinter posted. I can swap out the fuel pressure regulator in under 10 minutes.

Take off the plastic engine cover.

Unplug the regulator connector.

Place a towel over the engine since your going to put your face on the engine and reach with your hands to feel in back of the fuel rail.

The regulator has two bolts. Use a hex like the link says and a small 1/4" ratchet and remove the two bolts. Try not to drop them. U cant see the bolts, just have to feel them.

Replace the seals as they are cheap. I have replaced over 10 of those regulators and have a bunch of cores.

When I put the bolts back I use masking tape to tape the bolt to the hex just so it doesent fall off.

DO NOT TAKE OFF THE INTAKE MANIFOLD! THAT IS A HUGE JOB WITH THE ENGINE STILL IN THE VAN.
 
I'm not a mechanic (other than on my own Sprinter) and I totally agree with Pacman... Do not remove the manifold. I have swapped out my regulator many times trying to run down a problem that ended up being the high pressure fuel pump. Your leak is not coming from the fuel pump since the leak is at the rear of the engine.

The regulator/solenoid takes a e-torx 8. Be careful when you are removing to pull straight back and not up because there is a tip that could be broken off. There is a nylon washer and a green o-ring that come in the kit referenced above.

This said, I agree with others that this much of fuel leak from the solenoid/regulator might be unusual with it still starting.
 

dg55117

Member
Re: fuel leak on cold start- similar question

I have 2005 145K- never leaked a drop on anything. Yesterday, started- cold(15 degF) and let idle about 15 min - not on purpose. Noticed small spot on ground and had what seemed clear like diesel but not 100%. it leaked and dripped off front drivers side of oil pan but totally dry above that anywhere I could see /feel. Wiped the pan clean and drove 300 miles freeway ( checked under a few times along way) and it was completely dry. Parked in heated garage and no leaks - totally dry. Ram perfectly but it seemed to get a little less fuel mpg but could be due to cold/biodiesel and Powerservice additive
Does this sound like the stat of HP fuel pump? Can I check anyway for sure?
thanks
 

surlyoldbill

New member
Re: fuel leak on cold start- similar question

I have 2005 145K- never leaked a drop on anything. Yesterday, started- cold(15 degF) and let idle about 15 min - not on purpose. Noticed small spot on ground and had what seemed clear like diesel but not 100%. it leaked and dripped off front drivers side of oil pan but totally dry above that anywhere I could see /feel. Wiped the pan clean and drove 300 miles freeway ( checked under a few times along way) and it was completely dry. Parked in heated garage and no leaks - totally dry. Ram perfectly but it seemed to get a little less fuel mpg but could be due to cold/biodiesel and Powerservice additive
Does this sound like the stat of HP fuel pump? Can I check anyway for sure?
thanks
When you start it up in the morning and it's cold outside, IMMEDIATELY run out and look around the HP pump with a flashlight for drips. I used a heat gun on mine for a few mornings until the rebuilt pump showed up, and that worked. Kind of disconcerting to have fuel running down the front of the engine, even if it's only for a few minutes.
 

312d

New member
just to point out some things, i have not said he should take off the pressure regulator I said the other plastic clear tube, the one enlighten with red and second it is not difficult to take off the upper part of the intake manifold at least for me, the bottom part, well that is a PIA.
 

bobiz

New member
Thanks for you help guys Im gonna give it a shot will let you know how it goes .....I just remembered one more thing I just talked to one guy this weekend he deals a lot with older sprinters he told me that he buys those O-rings from Home depot or Lowe's in the plumbing isle where all the faucets kits are.he assured that they fit perfectly ..any one done this before...
 

surlyoldbill

New member
Thanks for you help guys Im gonna give it a shot will let you know how it goes .....I just remembered one more thing I just talked to one guy this weekend he deals a lot with older sprinters he told me that he buys those O-rings from Home depot or Lowe's in the plumbing isle where all the faucets kits are.he assured that they fit perfectly ..any one done this before...
I did not check the size when I replaced mine, I have the multi-kit from Harbor Freight with about 20-30 different sizes in it; and another one with SAE sizes. When replacing the o-rings on the clear fuel lines, I found that at least THEY are some odd size not in my kit. The ones on the rail solenoid may be the same way. BUT, if your friend says he can get the size needed in a packet at Home Depot, great! Let us know what the id/od/section size is for future reference.
 

Denislav

New member
Mine was leacking by the plastik end of the diesel return line
See this temporali fitting , go on Community - Pict. and Albums
 

Aqua Puttana

Poly - Thread Finder
just to point out some things, i have not said he should take off the pressure regulator I said the other plastic clear tube, the one enlighten with red and second it is not difficult to take off the upper part of the intake manifold at least for me, the bottom part, well that is a PIA.
The 5 cylinder NAS aka NAFTA OM612 engines I've seen do not look like the engine in your previous picture.

:2cents: vic
 

Aqua Puttana

Poly - Thread Finder
Re: fuel leak on cold start- similar question

I have 2005 145K- never leaked a drop on anything. ...
thanks
The OM647 engine high pressure pumps have some history of the rear fasteners becoming loose and leaking. The pump needs removal to correct, but usually no new parts.

If you trace the leak to the HP pump do an advanced search using high pressure with abittenbinder as member name. That should get the procedure. vic
 

312d

New member
The 5 cylinder NAS aka NAFTA OM612 engines I've seen do not look like the engine in your previous picture.

:2cents: vic
thanks Vic, then it would be nice that someone put some pictures to figure.
 

Aqua Puttana

Poly - Thread Finder

Top Bottom