View Full Version : Major Fuel Leak While running

09-28-2013, 03:16 PM

The other day I had a blow out and was towed on a flat bed truck to a tire center. The morning I turned the van on to drive it into the tire place from there parking lot fuel started leaking while it was running. After allowing the tire center to install my new tires I drove the van to a car wash to clean the engine and start from there on my search for the leak. After allowing the engine to cool, cleaning the engine, and running it again I couldn't locate the leak. When the engine is running enough fuel is coming out that it is splashing off the belt and fuel is being thrown about the engine compartment. It is coming out at a rate that it is pouring our from under the van while its running. Any help would be appreciated. I am technically inclined and have installed a fuel filter and other items. Any ideas as to what could be the culprit would be appreciated. I am a touring artist who must be in Phili tonight for a booked show. I also check the injectors (i think and it doesn't seem to be leaking from there.) How could this much fuel leak while the van is running? Ahh, The van emits more smoke than normal and has an odd smell in the cab other than diesel. Kind of like a burnt electronic smell. I'm clueless and I need of any suggestions you may have. I am willing to drop this thing off at a good mechanic but need to be pointed in the right direction. If I knew I could make it to Pittsburgh I'd drive straight to Andy. My baby needs to meet the Doktor.

If anyone knows of a good sprinter tech in NJ please recommend.


09-28-2013, 03:48 PM
Plastic lines from the filter to the high pressure pump and the clips that attach them have been the culprit of my o2 leak. Wrap paper towels around the lines where they connect to the high pressure pump to see if that is where your leak is coming from. Not sure if your year model is the same or not.

09-28-2013, 03:52 PM
What year is your Sprinter? This will help somewhat because prior to 2004, there isn't a low pressure fuel pump in the fuel tank. Will it leak with just the key on, engine not running? With that, here is the disclaimer from the service manual (I'm not shouting).



This method will help in determining the location of the leak. Is the leak from one side, front or back of the engine?


09-28-2013, 04:04 PM
The Sprinter is a 2002 2500. If it does not have the high pressure fuel pump then would that make the second posters idea null and void or could that still be the culprit. I can't seem to get it to leak with the key turned alone. It does make a weird noise with the key turned to the on position but not cranked. Some sort of electronic humm... Maybe its the pump froze up and thats what made the electrical smell???

09-28-2013, 04:09 PM
pfflyer: if the hoses are the ones on top front that run down to the right and to the fuel filter then no those don't seem to be leaking at the top where they connect to the engine/high pressure pump? Is that where the pump is located?

09-28-2013, 04:09 PM
Where are you in Jersey? I'm in Philly. I have lots of experience with fuel problems with an '02.

09-28-2013, 04:10 PM
If i remember correctly the hp pump sits high on the front of the engine on a 02. Follow your fuel line from the filter to the front of the engine and it connects to the hp pump. Chances are if the belt is slinging fuel it is coming from there. Could also be on the high pressure side as well so use above warnings.

09-28-2013, 04:26 PM
No. On an 02, the first pump after the filter is the low pressure one. Send me a pm and ill give you my number.

09-28-2013, 04:29 PM
pfflyer: Ok thats what I was thinking. I will take caution while searching for this leak and am glad to hear it must be one of these two lines due to the area the leak is in. Now the search must continue. Is there a quick professional way to search for this leak?

Type2Teach: We are broke down in Pine Brook, NJ up north. I could use that fuel knowledge you have. If it is a hose or clamp what would be the time to find a replacement for me and have it installed? Also is it really something I could figure out and replace myself? I could possibly have my van towed to your neck of the woods. I do have a show there tonight that I must make. After that I have until Tuesday before I must be back on the road.

09-28-2013, 04:34 PM
Looked back through my service records (van was sold six months ago and still have service logs) and Freightliner reference a low pressure pump as well as a HP pump. Mine would leak pretty bad when cold then got better as it warmed up. But it was leaking from around this pump. I was thinking they just replaced the lines but they put in a new hp pump as well. Said leak was coming from top of hp pump. There are service manuals online here for the 02 that you could get a better idea of what is what. Hope this helps some.

09-28-2013, 05:10 PM
pfflyer: You drove your van even when it had a major leak from the fuel pump? how many miles? was your belt getting soaked? Did you have no choice. My wonder is what is the major problem if I drive it like this to get over to philly? Then I could visit Type2Teach :bounce:

09-28-2013, 05:48 PM
Yes I did drive it but it leaked the worse when cold aprox 10"-12" dia puddle in 5 min cold and drops on the ground when warm. Drove maybe 200-300 miles after I discovered the leak over a 3-4 days before I could take it in and leave it over night so that they could get a cold start. Don't know if that was the smartest thing to do or not but I was never called the sharpest knife in the drawer. If it was gasoline I would have taken it right in or have it towed. Some fuel was hitting the belt but the majority ran down the block and onto the ground.

09-28-2013, 06:55 PM
After speaking with Type2Teach. I have inspected my lines and haven't located a real leak? I did however possibly find another problem. Check out my picture and see if you know what this could belong too and what it means. As for the fuel leak I am going with High Pressure pump and am going to get ahold of Doktor A for a rebuilt one. I would like to do one last inspection by removing the belt, fan, and radiator. Folding it all forward then start the engine and see what is happening on the bottom side of the engine where the fuel lines run in by the belts. I think the leak is in that area and I can't visually inspect there.

The photo is of a ring and the location i discovered it in while checking my fuel lines.

09-28-2013, 10:15 PM
Could it be a fuel filter o-ring? Its been awhile since I changed oil or fuel filters but it looks like it has square sides. Does either have rings with square sides? Could be an old one dropped after last change.

09-29-2013, 12:27 AM
Looks like an oil filter ring (or a fuel filter ring FOR A DIFFERENT VEHICLE). For reference, in the 2nd photo, you have the low pressure pump in the top left hand corner with the two clear lines running to it. The high pressure pump is in the bottom left hand corner with only part of it showing. It has the metal line running to the right. That metal line is full of high pressure fuel going to the fuel rail and then to the injectors. On the left/bottom side of the high pressure fuel pump (you can't see this in the photo) are two clear plastic lines. One is from the low pressure pump and the other is part of the return system for the fuel that is sent to the high pressure pump that isn't always needed. It's hard to see those two lines, but they are there. Based on the photo and the lack of fuel showing on that side of the high pressure pump and the low pressure pump, my guess would be to look at the other side of the pump for your leak (left/passenger). maybe where the two lines go into it or maybe even the fuel pump itself leaking.
Where is your show? My wife and I unexpectedly found ourselves with a babysitter and a free night. Call or text if you get this before the show is over.

09-29-2013, 05:08 AM
Could the mystery o-ring be from the intake hose at the EGR?

09-30-2013, 06:40 PM
Tried moving the van 3 miles down the road to an Autozone. Van had catastrophic electrical failure and died while rolling in the parking lot. Heard clicking sounds under the seat after turning it off. Not good I'm guessing. Un hooked the positive terminal and am now letting the engine dry. Now that this has happened I feel it's time to give in and take it to a shop. I was confident in replacing the high pressure pump and more importantly maybe just a possible tightening of bolts but now it seems to have escalated into one of those really really big problems. Depending on what anyone might know about electrical problems. Fuel is all over the inside of the hood so anything could've fried.

09-30-2013, 06:49 PM
Would it be best to take to a freightliner or just a good diesel mechanic shop? I ask this because of the electrical problem.

09-30-2013, 07:54 PM
I got my 02 for cheap because it was towed from shop to shop to shop and finally declared "dead" by a diesel mechanic who was unfamiliar with sprinters. I replaced the fuel filter, lines and high pressure pump and had a running van. I would take it to a sprinter dealer (freightliner or mb) or, since you arent too far, have it towd to andy in pittsburg. I cant tell you how many people have spent hundreds or more at a shop only to tow their vans to andy to get it all truly sorted out.
Good luck. Keep us posted.

10-01-2013, 03:04 AM
Ok, so after sitting a few hours. Washing the engine and hoping for the best I reconnected the battery and power worked! Then I went through the steps of removing the HP fuel pump cleaned it. Tighter three lose bolts on the inside even though I am of the understanding that only works on 04-06 models. It stopped the leak temporarily and when I'm driving it leaks a ton less. When I'm not driving fuel is literally pouring out. I have now PM'd Andy for a rebuilt HP pump that I badly need to get in my van.

Side story

I was moving the van 3 miles to autozone and two firefighters pulled up next to me and said " your van is leaking fuel." I told him I knew that in which he replied "No it is literally pissing fuel" and I replied again "I know I'm just heading up the road here." It was an odd interaction I felt I should share. Maybe not so smart to drive with fuel pouring out but when left with no other option you go with plan A. The only plan.

Also after reinstalling the pump but also after the electrical hiccup my ABS light and traction tire symbol is on. Not sure about those....

10-01-2013, 09:46 AM
I know liquid diesel isn't flammable but I'm surprised they couldn't think of some fuel related fire code violation to hit you with?

Whilst diesel is not a fire risk, it is toxic, and slippery and will attack the paved surface of the road, I think you are really lucky not to have been pulled over by the police, especially after the firefighters saw you.

I don't usually give out lectures, but please have some consideration for other road users!

(I'm probably just grumpy because after I noticed damp on my car's fuel tank last week which seemed to be from the rusted flange I have spent all week painting a new one and trying to change it over. I gave up at 2245 last night after hours of fighting to get the hoses reconnected in a tiny space I could barely get my hand into when I discovered that the flange sticks out just too far and needs bending down in a couple of places to make it fit - I thought the bends in the flange of the old one were damage. I'm sore, tired, had to cylce to work today and I have to back under tonight and lower it enough to tweak the flanges and then hopefully get it it far enough up to connect the straps. Follow that up with touching up the paint where I chipped it already, refitting the exhaust and then all the hassle of trying to bleed the fuel system before I can restart it. Oh yeah, I guess I'll need to put the diesel back in it at some point too).

Aqua Puttana
10-01-2013, 11:33 AM
Also after reinstalling the pump but also after the electrical hiccup my ABS light and traction tire symbol is on. Not sure about those....
My guess is that your leaking fuel has washed into various electrical parts and the contamination is causing your electrical issues. What happens further is anyone's guess. vic

10-02-2013, 05:11 PM
Thank you everyone for your input. After ordering a rebuilt High Pressure fuel filter and installing it all of my problems are fixed. We no longer have a fuel leak and all warning lights have turned off. I'm more ecstatic than anyone could imagine. Now we are in route to Atlanta. Again hank you everyone and I'd like to send a thank you to Type2Teach for the phone cal and Doktor A who explained some things to be I couldn't have learned anywhere else.

For those worrying about changing the High Pressure pump on your own. Don't. It's an easy job that only requires a few tools and the manual.

10-02-2013, 05:38 PM
Where are you playing in Atlanta?

10-02-2013, 08:23 PM
Some inspiration for a new song?
Glad to hear all is well and you are back on the road!


10-02-2013, 10:12 PM
Pfflyer I will get the venue name time and address and pm it to you. I will also get you and any of your friends in on our guest list if you end up wanting to come. We are booked for the A3C festival going on this week.

After getting the van back up and running we now seem to have a small coolant leak. From what I can tell it is coming from the driver side further back behind the fuel filter up high. Does this make sense to anyone??? I am about to search through the forums now. Just figured I keep this thread of problems going since they seem to e a cascading event that started with a rear passenger side tire blow out.

10-02-2013, 10:14 PM
Bc339 yes it will be titled "leaky" LMFAO!

10-02-2013, 11:47 PM
Your coolant leak sounds like it could be coming from the electric coolant pump area. It is mounted to the firewall, above the fuel filter. It has two coolant lines and an electrical line connected to it. Hopefully nothing more than a loose clamp.
(Image is from an '03)


10-03-2013, 01:30 AM
Bc339 that is exactly the area it's coming from. I will re set the clamps and see what happens. It is getting worse I think. Now my reservoir empties in minutes of driving. This has been a rough week for us. Hopefully after this shell give us another solid three months like she has done these last three months.

I've taken a few photos but the one you posted sums it up.

Bc339 You are referring to the horizontal cylinder at the top of your photo with a hose going into it on the left side of the photo and one coming in from what looks like the top on the left side as well? Thank you for this information.

10-03-2013, 01:52 AM
Yes, your description is correct - the horizontal cylinder device is the electric motor for the electric coolant pump.
If the pump housing is leaking and you can't stop the leak, there's no reason you couldn't bypass the pump by installing a tube (something like flexible copper pipe from Lowes or Home Depot) to the two water lines until you can get a replacement pump. Don't cap the lines, but connect them together.

This is the purpose of the pump from the service manual: The electric coolant pump ensures the uniform flow of coolant through the heater core without bubbles, even at low speeds.

Since your in a jam, take care of the leak first, but don't leave it this way.


10-03-2013, 04:09 AM
Ok, it seems to be coming from the pump. I will take the hoses off and the pump. Check any external bolts or screws for looseness then re attach and see what happens. That hose is for the heater core? If I by pass it will coolant still flow? Just not uniformly? I can order the part ASAP I just need to keep moving.


10-03-2013, 04:17 AM
If that is the heater core pump I would think that it only works when the heater is on but I will let someone with more knowledge than me answer. Hope you have a safe and un-eventful trip.

10-03-2013, 09:50 AM
That pump almost threw me - do you have an auxiliary heater that you can use without the engine running, either for pre-heating the engine or warming the van?

I know that there is an additional pump when one of those is installed, but I can't see why you would need anything other than the engine driven coolant pump for normal driving - but I don't have experience with a van that age.

If it is the pump for the auxiliary heater, you can bypass it and just not use the auxiliary heater, it is only needed when the engine isn't running to move the coolant around if you have the auxiliary heater on.

Good luck, sounds like your tour is turning into an ordeal!

10-03-2013, 01:00 PM
Boater after 65,000 miles we have had great luck from what I read on the forums. She has treated us very well and after three months of no hassles I'm pretty happy considering the things that could go wrong.