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Kevin_Todd's avatar
Kevin_Todd
Explorer
Jul 21, 2015

Dodge turbo question

Got a '02 2500 with the gen 2 5.9. Truck has been flawless, but I noticed something this week and need some help from you guys that are better wrenches than I'll ever be. I don't hear my turbo spool up anymore, and noticed during a tow that I couldn't feel any boost. After removing the front hose from the air filter box, I can spin the intake blades fairly easy. How free should this be? Had one guy tell me it should spin for 20 seconds after you spin it with your fingers. Opened up the exhaust by getting rid of the resonator and muffler and replacing with a straight pipe. at 250K, the turbo I guess has some wear. I noticed a slight bit of side to side movement of the shaft but so little you can' see it, only feel it when you have the 12 point nut between your fingers. All the boots on the intake side look good. I did notice some gunk in the front of the intake side. Anything else I should check?
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  • Cummins12V98's avatar
    Cummins12V98
    Explorer III
    Jul 21, 2015
    Tighten ALL your pressurized boots.

    Last time you checked your air filter?
  • path1's avatar
    path1
    Explorer
    Jul 21, 2015
    Had one guy tell me it should spin for 20 seconds after you spin it with your fingers.


    Well that's a reliable test, so what would 19 and 1/2 seconds mean? :B

    If you don't have a good set of gauges you could be guessing at problems. Throwing money at them and the price of turbo's I wouldn't want to even guess. Your truck has several weak points and 99% of them can be worked around or fixed. The final goal IMO is to end up with a very dependable tool and not a "wallet flattener".

    As far as turbo goes learn about "floating bearings" http://www.cumminsturbotechnologies.com/ctt/navigationAction.do?url=SiteContent+en+HTML+ProductsAndTechnologies+Bearings

    Fully Floating Designs that Set the Mark for Durability
    Journal bearings are of the fully floating ring type, which means that the ring is free to rotate and there are two oil films, one on the outer diameter of the journal, the other on the inner. Predominantly, this system is used in automotive turbochargers, although some large industrial and passenger car units use rolling element bearings fed by an integral oil supply. All current Holset Turbochargers use fully floating designs.


    Notice the part of
    Oil is transferred from the outer to the inner film by radial holes drilled in the bearing.


    That's one big reason I cool mine down before shutting off. Easy for those holes to get "coked" up and block the passages as they are not that big and another reason to keep up on oil changes IMO.

    This might help you also. http://www.cumminsturbotechnologies.com/ctt/navigationAction.do?url=SiteContent+en+HTML+PartsAndService+Turbocharger_Diagnostics

    OK just my two cents, Hope it was useful to you.
  • KMLsquared's avatar
    KMLsquared
    Explorer
    Jul 21, 2015
    If you turn your key on and of three times leaving it in the on position it will display any stored codes in the odometer window. You need to pause slightly in the on position each time. There are several lists in the internet that will tell you what the codes if any mean.

    As far as your turbo, I've always gone by the "if its not rubbing metal to metal" its fine. The turbine actually spins supported by engine oil and pressure.
  • C_Schomer's avatar
    C_Schomer
    Explorer
    Jul 21, 2015
    Should have NO end play but a little radial play is normal as long as the wheel doesn't touch the housing. It won't spin on it's own very long cuz it runs in an oil film. Keep the boost boot clamps tight... the hot side clamps loosen and need to be tightened oftener. It doesn't take much of a hole in a boot to lose the boost. I've had to remove them to find the tiny holes.
    Just a heads-up on that truck... the engine breather is at the front and they can really cr@p up the radiator and cause overheating. BTDT with friends first 24v CTD trucks. I've had to pull the radiator to clean them good and extend the breather to the rear with a hose. Craig
  • flyairam's avatar
    flyairam
    Explorer
    Jul 21, 2015
    Kevin,

    Did you get a check engine light as well? Your '02 truck has the VP-4400 fuel pump and a low injector volume could cause this perceived turbo problem. If the VP-4400 starts acting up it sometimes throws a code with the associated CEL. In this scenario you'll also have a drop in power and/or hard to start.

    To explain further, your turbo extracts heat energy from the exhaust and converts this energy into boost. If injection volume is low exhaust volume will be low and you won't hear your turbo spool up in the normal way.

    Gauges, EGT and boost, would make this problem easy to diagnose.

    Sorry I haven't given you any answers, but you might be barking up the wrong tree.

    Randy
  • fj12ryder's avatar
    fj12ryder
    Explorer III
    Jul 21, 2015
    Check all the hoses between the turbo/intercooler/intake manifold. Make sure you don't have a bad hose somewhere. You really need a boost gauge to see what's going on. And an pyrometer too just to make sure you're not overheating things on the exhaust side.

    A boost gauge will set you back around $65 and is easy to install, no holes to drill. Just pull one of the intake manifold bolts and use the supplied fitting. You might check with a local diesel shop, they may have a temporary boost fitting and gauge that you could borrow. But I would check all the hoses and hose clamps first.

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