Clang/Clatter noise in upper end low oil pressure

Discussion in 'Engine, Fuel and Exhaust' started by Shipper, Dec 28, 2011.

  1. Shipper

    Shipper Member

    I have a 91 Softail. EVO motor. 42k miles. Aftermarket Cam and lifters and Pipes. S&S Carb

    After a ride I started to hear a clang/clatter and noticed that my oil pressure was done to nothing.

    I restarted it the next day and the oil pressure was right up to 35lbs.

    Took it out for a ride and I could hear the clang/clatter again but the pressure was OK.

    After 10 miles, the clang got worse and the oil pressure constantly dropped over time.

    The Clang seemed to come from the upper end of the front cylinder.

    I took the rocker cover off. Nothing obvious...

    Took the lifters out. Nothing obvious....

    Any great ideas????

  2. Jack Klarich

    Jack Klarich Guest

    Clean the tappet screen? Have you done any mods to the engine recently?
  3. Shipper

    Shipper Member

    Yeah, I checked out and changed the screen. It was fine. Thanks.
  4. R. Lewis

    R. Lewis Senior Member Retired Moderators

    How long ago did you put the cam/lifters in?
    What size/style of cam?
    Have you rechecked the cam/lifters?
    Does the clang/clatter get louder the hotter the engine gets?
    Is the clang/clatter present at idle?
    Have you lost any torque?
    Have you done a compression test?
    What weight of oil is in it?
    Have you checked the oil pressure system?
    Did anything in our self-help section offer any ideas?
  5. Shipper

    Shipper Member

    The Cam Lifters are more than 5 years old; 10k miles???? They were in the bike when I bought it.
    It's a "hotter Cam" Not sure which.
    Yes, the noise gets worse as the motor heats up. And the Oil Pressure steadily drops as the motor heats up.
    Clang is there at idle.
    Torque seems fine. Sounds OK. Runs OK.
    Oil pressure starts out at 35psi and drops to zero as it warms up.
    The oil is the standard V-Twin oil. 10W-50??
    No, I have not done a compression test yet.
  6. Jack Klarich

    Jack Klarich Guest

    What New Hydraulic Lifters Should I Use. - Harley Davidson Community change the lifters
  7. Shipper

    Shipper Member

    Thanks Jack. Good link.

    HDWRENCH Member

    Common issue with EVOS is a sheared oil pump drive gear. Most times this is caused by a lifter loosing a needle bearing and it gets between the two gears and the oil pump drive gear key gets sheared off. The problem is that it will make enough oil pressure for a period of time to keep the oil light off but not enough oil is flowing through out engine.

    Re check the lifter rollers if one is loose a needle bearing is gone. If that is not the case look at the end of oil pump shaft where the gear is. If the slot on the shaft is not lined up with the gear slot that is the issue.

    We just had one come in for that issue. Customer had another shop re adjust push rods to cure noise. :11: Well it fixed it for a short time until the rest of the bearings spit out of the lifter and took out the engine.

    No oil pressure on a evo that is run = a total loss most times. As the cost to fix it vs buying a new crate engine is so close.

    Oil pump shaft bushing is another issue but not as common. If the bushing fails it will lock up the pump and the key shears and it no longer providing oil.

    Hope it turns out to be something simple and that you have no engine damage.