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a fuel pump chevy diesel 6.5??

Discussion in 'Truck & Equipment Repair' started by Sealer People, Dec 14, 2008.

  1. Sealer People

    Sealer People Senior Member
    Messages: 210

    hello again lol,, ( 2 in one morning )

    6.5 turbo diesel, 1996 chevy 2500 4x4
    normally when i turn the key to start & wait for the glow plug light to give the ok to start,,,,,
    I normally hear a long clicking noise,,,, that normally stops when the wait to start light goes off.

    Recently when it gets very cold outside,,, the truck doesnt make that noise,,, when its mild out it does,,,, but nothing when its very cold,,, i thought it was the glow plug relay,, but my mechanic says he changed it, then i had it checked by another mechanic and they said evrything is good.....

    anyways,,, could this clicking noise be the fuel pump ???
    & if yes,,, then why doesnt it pump or make the noise when its very cold outside???

    the truck is plugged in on cold days, & always starts easy ( till now )
    no fuel problems as of yet ie, shutting off, loss of power etc.

    any thoughts???
  2. SGC08

    SGC08 Member
    Messages: 71

    Does it start and run OK when its cold outside? If so, I would rule out the fuel pump. It may run with the lift pump not working but won't for very long without drivability issues, mainly a loss of power and sputtering.

    If I remember correctly, the lift pump on the last 6.5 I had was pretty quiet. I had a 2000 and it was under the truck on the driver's side frame rail just behind the driver's seat. I'm not sure if it is in the same spot on your 96 but once you find it, put your hand on it and have a friend turn the key. You should be able to hear it and feel the vibration if its working.

    Does the noise change with the operation of the glowplugs? Does it start or stop with the glow plugs?
  3. Sealer People

    Sealer People Senior Member
    Messages: 210

    when i spoke to my mechanic yesterday he mentioned the lift pump.

    the truck starts & runs just fine right now,,, only when its very cold outside it just doesnt make that vibrating noise. but it still starts fine & runs well.

    again,, only when its very cold does it not make the noise, when its mild outside the vibrating noise (trrrrrrrrrrrrrrrrrrrrrrr) lol,,, it goes on like normal.

    could that be the lift pump ?
    is it an expensive fix ???? by the mechanic.

    thanks in advance
  4. lilweeds

    lilweeds PlowSite.com Addict
    Messages: 1,178

    lift pump is about the size of a Chevy fuel pump. Easy fix, however I don't think that would cause the symptoms your having.
  5. SGC08

    SGC08 Member
    Messages: 71

    I wouldn't think it is the lift pump. I don't think the temps would cause it to stop working and if it was, you would experience very noticable performance issues. The lift pump is about $100 and should take less than an hour to install.

    Does the noise start or stop when the glow plugs turn on or off?
  6. Sealer People

    Sealer People Senior Member
    Messages: 210

    the noise always starts when i turn the glow plugs on. I always thought the clicking noise was the glow plugs wartming up.
    someone told me yesterday that i was a pump because it was coming from behind the cab.
  7. BFDChief

    BFDChief Junior Member
    from nj
    Messages: 1

    Lift Pump

    Sorry this is a late reply to your problem but I am new to plow site and I was just searching lift pump problems myself, and came across yours. My fathers truck, which is my old 97 Chevy 2500 6.5 diesel ex-cab P/U. Recently the truck sat after my father was on Vacation for a week. When he returned he found that suddenly he had a loss of power at exactly 40 MPH. The truck would spit, sputter, and sometimes stall, also blowing some grayish blue smoke. What it has come down to is a bad lift pump. The noise the lift pump makes can be described as a purring sound under the drivers seat. I found diesel forum site that helped me with a very simple test of the lift pump. http://www.dieselplace.com/forum/showthread.php?t=39350
    Under the hood, top of the motor by the T-stat is a small valve with a T- handle. Out of a small hose off that valve you should get fuelout if opened while the truck idles. If your lift pump is bad it should cause the motor to sputter and eventually stall. It will rob the fuel out of the filter bowl. Also you should get fuel out the top of your fuel filter if the pump is working. Hope this helps.
  8. augerandblade

    augerandblade PlowSite.com Addict
    Messages: 1,054

    The lift pump may be telling you on cold days that it is on its last legs. However it wont comeon if there is enuf pressure in the system between pum p and fuel injector.