2004 Injector Pump LOUD!!!!!!!!!!

porschecab

New member
I am recently the owner of a passenger 144. I have (though just sold last night) a 118 Cargo and these two sound VERY different.
The 144 has a very loud HMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM from about 30 seconds AFTER it fires up and stays on until the vehicle is turned off. The HMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM will go about 5-6 seconds beyond the shut down of the vehicle. I am being told by friends it is the injector pump (sitting on the top / front of the motor) making such noise.

The Cargo doesn't do this. I can hear the noise AT speed on the freeway and that is with M/S tires. Does anyone else experience this?
Should I be concerned?

Oh, anyone know where to source the Mercedes Benz LETTER STICKERS that go above the rear license plate...?

Thanks!
 

mackconsult

New member
Mine does this also. I believe it is the Mass Air Flow Sensor. I don't know what it means, but I think it means it is going to fail at some point.
 

220629

Well-known member
...
I am being told by friends it is the injector pump (sitting on the top / front of the motor) making such noise.
...
You don't say what year, but this is the T1N section. If it is a 144 it should be an NCV3 model. (Your signature is a good place for your vehicle info.)

I find my 2004 has a similar sound and timing, but it is the electric coolant circulating pump mounted on the firewall. You'll find it kinda basically back of the EGR. I think it's unlikely your mechanical high stage injector pump would make that noise because it doesn't run after the engine stops. If you have an OM647 engine (NAFTA 2004 - 2006) your low stage fuel pump is in the tank. On OM612 engines (NAFTA 2001 - 2003) the mechanical low stage pump stops with the engine. The OM642 engine low stage pump is in the tank.

IF it's the coolant circulating pump I wouldn't be too concerned. That is said with never seeing your vehicle so FWIW. Have fun. vic
 
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abittenbinder

Doktor A (864-623-9110)
I am recently the owner of a passenger 144. I have (though just sold last night) a 118 Cargo and these two sound VERY different.
The 144 has a very loud HMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM from about 30 seconds AFTER it fires up and stays on until the vehicle is turned off. The HMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM will go about 5-6 seconds beyond the shut down of the vehicle. I am being told by friends it is the injector pump (sitting on the top / front of the motor) making such noise.
If you can trace this loud hum to vibrating fuel lines under the cab floor then this is likely the high pressure pump's, fuel pressure relief valve.

Replace with Dodge part# 5166878AA. Doktor A
 

porschecab

New member
I have a 2004 144 Passenger Sprinter.

The sound is coming directly from the top front center of the motor - any other suggestions/ideas? It (whatever it is) starts about 15-30 seconds after the Sprinter fires up and runs about 4-7 seconds after it has been turned off. The sound is not coming from anywhere other than the top/front/center of the motor - and it runs the entire time the Sprinter is running.

Thanks!
Dan
 

WAYNERODD

Member
I have a 2004 144 Passenger Sprinter.

The sound is coming directly from the top front center of the motor - any other suggestions/ideas? It (whatever it is) starts about 15-30 seconds after the Sprinter fires up and runs about 4-7 seconds after it has been turned off. The sound is not coming from anywhere other than the top/front/center of the motor - and it runs the entire time the Sprinter is running.

Thanks!
Dan
Dan, I would go with Doktor A's suggestion. It fixed my problem. Same noise except my in tank fuel pump was also loud.

Wayne
 

220629

Well-known member
I certainly listen to Doktor A before listening to me.:thumbup:

Except when I hear those voices nobody else seems to notice. They just won't go away and are hard to ignore.:eek:

:bounce:
Good luck. vic
 
You don't say what year, but this is the T1N section. If it is a 144 it should be an NCV3 model. (Your signature is a good place for your vehicle info.)

I find my 2004 has a similar sound and timing, but it is the electric coolant circulating pump mounted on the firewall. You'll find it kinda basically back of the EGR. I think it's unlikely your mechanical high stage injector pump would make that noise because it doesn't run after the engine stops. If you have an OM647 engine (NAFTA 2004 - 2006) your low stage fuel pump is in the tank. On OM612 engines (NAFTA 2001 - 2003) the mechanical low stage pump stops with the engine. The OM642 engine low stage pump is in the tank.

IF it's the coolant circulating pump I wouldn't be too concerned. That is said with never seeing your vehicle so FWIW. Have fun. vic
I agree with AP here. I have an 04 and it hums in almost a high pitch hum but I think mine is either the EGR or the coolant pump and it goes for about 10 seconds after I shut it off. I can't really hear it driving down the road though so if you yours is getting that loud record it and put it on here so we all can have a listen. I recommend doing it just after the motor shuts off so we hear it clearly!
 

flan8tive

New member
Replacing High Pressure Relief Valve Advice

Decided to banish the Hum.

New MB pressure relief valve in hand. 16mm socket at the ready.

Looking for a write up on this or some advice on change out. Does it sit aft and right (facing engine bay) of the injector pump? Reached in today and couldn't tell where it was.

Do you access it by detensioning the serpentine and is it smarter to work from the top or crawl underneath and use a socket extension?
 

220629

Well-known member
Re: Replacing High Pressure Relief Valve Advice

...
Looking for a write up on this or some advice on change out. ...
Use Turbo John as a member name in advance search. He put out a description of the parts change and some notes for diagnosis. If it is the fuel system making the noise it is not immediately fatal (never?) so you have time to do some research. vic
 

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