Whining in Tank Fuel Transfer / Lift Pump

[WEnos]

I have a 2006 Quad Cab with 50K miles. The other morning when I started it up I could clearly hear the lift pump. Had a definite high pitched whine and I have never heard it before. My wife asked me this weekend what the noise was after starting up. So it is not just me. It was very low on fuel so I added 5 gallons from a spare can that I keep on hand. . thinking that maybe since the pump is in the tank that it needed to be covered. Well it still audibly whines. You cannot hear it from outside. . only while inside. I lifted the left rear seat and then it was noticeable with the door open.



Definitely has me raising an eyebrow. Really do not want to discover on trip this winter that it was going bad and the consequences that go along with that. . towing. . additional damage etc. IF this forum's community feels that it is working on failing. . then I am all over fixing it ON my schedule. My thoughts would be to have a non-OEM pump installed. . ie. . FASS or similar. . also adding additional filtration at the same time.



Any experienced thoughts would be appreciated!

 

[DeezelDood]

Did the whine get better with full tank? No exp with this on my truck but the lift pump does normally emit a little hum. These new in tank pumps recirc most of their output back to tank. The whine may have been cavitation cause by air bubbles or low suction head. The fluid level may also act as sound absorber, conversely, very low fuel level may make pump seem noisier. If allowed to cavitate long enough the pump can wear out. Next time you fill up your tank note how much foam appears in the fill pipe from the agitaton. It disipates quickly but continuous agiation is another matter. I never go below 1/4 tank and usually fill up at 1/2.

 

[BIGNASTY]

Hope you find out what it is before it leaves you stranded away from home where a repair would be MUCH BETTER. That's the thinking that came to me when my lift pump went out and still under warranty. The fix from Dodge was to put the IN-TANK pump on. We travel and I didnt like the idea of having such an important part of the fuel system in such an inaccessible place in case it went out say on I 70 between UT and CO were the only thing out there is NOTHING. At least it could be replaced with another pump without dropping the tank. So I went with the AD100 and have not regretted it except for the fact that I had to add additional filter/water sep to what spec's I wanted. Would have rather bought an AD raptor pump or equivalent and just put the Cat 2 mic and the Baldwin WS that I have.



BIG

 

[WEnos]

Well a great ending to this question. I discovered today that it was actually the inverter that I installed within the rear seat storage space making the whine. I had forgot that I had put it there and it is not really visible. Apparently the fan is starting to go out and with the whirring whine. . made it sound very much like a pump. The inverter comes on when I turn the key. . so the other morning when the glow plugs were having their way the fan was whirring away and immediately I went to the lift pump. Today the pitch changed just enough that my lightbulb finally went on and i remembered the inverter. Sure enough that was it. Thanks very much for the responses. . they truly appreciated.

 

[BGlidewell]

FYI: replacing the fuel pump is pretty easy. The hardest part is getting the fuel lines off. (eventually I used tywraps to squeeze the connectors while I puled them off) If you ever need one, autozone sells the OEM for around $150. I had to replace mine when I broke one of the fittings on the original while replacing the fuel tank.

 

[sarahjoe]

Definitely has me raising an eyebrow. Really do not want to discover on trip this winter that it was going bad and the consequences that go along with that. . towing. . additional damage etc. IF this forum's community feels that it is working on failing. . then I am all over fixing it ON my schedule. My thoughts would be to have a non-OEM pump installed. . ie. . FASS or similar. . also adding additional filtration at the same time.

 

[Prairie Dog]

At 50K your pump has MANY miles left in it. I would leave it alone.