disturbing noise- fuel pump???

I have an '06 with almost 400K on it. Recently had a noise that sounded like fuel pump (whining/whirring from time key was turned on and for several seconds after motor was shut off). Some searching here brought me to the conclusion that it was my HP pump relief valve, so I replaced it (challenging to say the least) and the noise was still present but not nearly as bad. Since then I've used the van for one trip (200ish miles) and it's been sitting for a month after that. Drove it today and the noise is back and loud and constant. It's loudest in the cabin, in drivers floor area- can hardly hear it under the hood. Suggestions?

The in tank electric pump will run when the ignition key is turned to "On" and then cycle off after some seconds if the engine isn't started.

Have someone turn the ignition key to "on" without starting the engine while you are under the tank to listen. That may help isolate the source of the noise.

If the noise happens with the key on, engine not running then it may be the electric pump... or maybe not. If the noise doesn't start until the engine is running it could still be related to the high pressure pump. (Even a new part could still be buzzing.)

vic

The EGR goes through a cleaning cycle after the engine is turned off. It's a high-pitched whine.

--dick

The tank fuel pump is usually pretty quiet. The only time I have ever really heard it making abnormal noise was one winter when my fuel gelled up and the pump couldn't pump properly.

Noise starts with key on before starting engine. Van had GDE tune and EGR deleted.

Get on the ground, and have someone turn the key to run. You should be able to hear the fuel pump if its loud. The noise will often come from the fuel lines under the drivers feet as well.

It would probably be simpler to pull the fuel pump relay



--dick

You will have to turn the volume way up, but is it this noise? (fuel pump relief valve)

https://www.youtube.com/watch?v=CGws_OZ_1S8

Weird- when I drove home Friday all I got was the normal fuel pump whirr before starting and a few seconds after shutdown, no more constant loud noise. Drove it again yesterday, still quiet. Why are there 2 pumps? If the in-tank pump fails, as long as the system is "primed' will the HP pump provide enough suction to allow normal operation? I failed to mention that other than the noise, the van runs great. In the last thousand miles I've replaced the fuel filter, WIF sensor (was leaking), split turbo hoses, and HP pump relief valve.

No, if the in-tank pump fails the engine will not run, period. The HP pump needs around 60psi to function properly.

The i tank pump is a high volume low pressure pump that feeds the high pressure pump. The high pressure pump does not have the ability to draw and boost.

To (try to) slightly clarify for drop-in readers: the 2003 and earlier Sprinters had a mechanical low-pressure pump on the engine, which sucked fuel up from the tank, through the filter and thence into itself (for delivery at about 57 psi to the high pressure pump).
Those years had the problem that minor leaks in the lines between tank and pump would allow air in to break the suction.

From 2004 (OM647 engine) onwards, the US/Canada Sprinters have an in-tank electric pump that pushes the fuel through the lines and filter. Leaks along the way make fuel on the ground. The US/Canadian OM647 no longer have a mechanical low-pressure pump on the engine.
Hence: no electric pump, no fuel reaches the HP pump.

The 2003 and 2006 service manuals at http://diysprinter.co.uk/reference discuss the different low pressure pumps in their "Fuel Delivery" sections.

--dick

Is your 2006 definately a T1N?
On the NCV3, there is a fan on the Audio 20 system as I understand it.
Could it possibly be that?

https://www.youtube.com/watch?v=y9iRjLVo9cg

I had this noise and it turned out to be one or both (bought two new ones on amazon and replaced them) the big relays that plug into and from the bottom of my 2003 fuse box below the steering column.

Is it possible it's the electric circulation pump giving up the ghost ? Right location...The manual doesn't state if the pump is operational when key is on only, and/or when vehicle is running under 17mph. How does GDE tune/EGR delete effect Circulation pump operation?...Probably not it if he can barely hear it under the hood...

Добрый день У меня тоже такоебыло после того как заправился на не очень хорошей заправке. Результат - Снятие топливного бака и прочистка сеточи фильтра топливного насоса. Такое впечатление что в топливе была разбавленна глина и вот эта глина и забила полностью сетчатый фильтр.

sergeiosv said:

Добрый день У меня тоже такоебыло после того как заправился на не очень хорошей заправке. Результат - Снятие топливного бака и прочистка сеточи фильтра топливного насоса. Такое впечатление что в топливе была разбавленна глина и вот эта глина и забила полностью сетчатый фильтр.

Click to expand...

Good afternoon I, too, this was after I refueled at a not very good gas station. Result - Removing the fuel tank and cleaning the fuel pump filter mesh. It seems that in the fuel was diluted clay and this clay and completely clogged the filter.

Thank you all for contributing to this thread. My '06 developed the same buzz from the in-tank filter, a few months and a few thousand miles ago. It's still occurring now, mainly in warmer weather (70+ degrees) after driving a few hours. But it's getting a little worse, doing it in cooler temps.

Here's my question: Does anyone know the risk if I just ignore it and put up with the buzzing? I prefer to save my time/money for the "must have" repairs and ignore the "nice to have" annoyance repairs. But if the buzzing is overly straining my low-pressure in-tank pump and sentencing it to an early death, I'll move the relief valve work to the must-have list.

Thanks,
Jake

My 2005 Sprinter T1N hosting an Itasca Navion with only 53k miles developed a very noisy buzzing in-tank fuel pump. Ran it for many trips like that over almost a year, until eventually the CEL/SES light came on and it went into limp mode. My OBDII code reader reported P0087 (low fuel pressure) and P2047. I could clear the codes and resume normal driving . However, any time I tried climbing a steep grade and put the gas pedal into it to send the turbo into boost, the same fault would happen. If I was gentle on the gas, down shifted on grades, and took it easy to avoid turbo hi-boost, I could run fine & never trigger the CEL. On flat ground or mild grades I could run at hiway speeds no problems, but keeping speed up on grades would trigger the CEL and P0087/P2047 codes. Since this behavior was symptomatic of fuel starvation under load, and because of the fuel pump loud buzzing, and also the P0087 code (low fuel pressure) I suspected the in-tank fuel pump (or fuel filter). I rolled on a creeper under the fuel tank, started the engine, and listened/felt the tank. Definitely a very abnormally loud buzzing and vibration coming from it's in-tank pump. Never had a gas in-tank pump sound that loud and couldn't imagine why a diesel in-tank should be any more noisy.

So after a trip where I made sure to use up almost all the fuel, I dropped the fuel tank, pulled the pump, and had a look. (Pretty easy to drop the tank if it's near empty). Here's a picture of the pump assembly:


The pump's electric motor is in the center of the lower section of the canister. Inspecting the inside of the "well" the motor sits in, I could see some blackish brownish debris around the perimeter of the pump. I could scoop out a little of it with a screwdriver and found it to be a slurry of rubbery feeling particulates clinging together the way wet sand clumps/clings...only the stuff feels kind of rubbery.

Then i took a look at the end of the fuel-pickup tube. YIKES. Attached is a picture of it. There's supposed to be a plastic strainer on the end and that strainer was totally coated in this compacted sort-of rubbery slurry. I couldn't see the features of the underlying strainer.


I scraped off some of that surface gunk and you can now see the structure of the strainer. You can also see what this gunk looks like.


Then I looked at the bottom underside of the pump assembly and found more of this clumpy stuff stock to the bottom "stand-off" features of the plastic canister.

Anyway, I can well imagine this contamination, which evidently is also plentiful inside the tank, clogged the fuel pump's intake strainer pretty badly. It's also likely the fuel filter is clogged from this stuff. At minimum, the clogged intake would make the fuel pump work much harder and maybe cavitate, causing the loud buzzing, and obstruct fuel flow. If the filter is obstructed too (likely), the combination of the two would work the pump pretty hard.

So this is almost certainly the cause of the buzzing and CEL P0087 codes. I'm going to take the tank to a shop to get the remaining fuel & gunk sucked out so it's clean, replace the filter, and replace the fuel pump (if I can't adequately clean the present pump).

Anyway, my question is this: Has anyone seen this kind of contamination before? What is it? This is my first RV and first Sprinter experience, and I bought this rig used, as I say only 53k miles. How does this much gunk arise with so few miles? Is it likely someone used dirty biodiesel? What's the community experience with fuel contamination like this and where it comes from?

Thanks.

I would guess a pump failure at the filling station. Obviously the pumps filter was MIA. It could also be microbial growth, but that's not normally rubbery, it's slimy.