Results 1 to 7 of 7

Thread: Oil Leak (Where Would It Be Coming From)

  1. #1
    Join Date
    Mar 2017
    Location
    ND
    Posts
    20

    Default Oil Leak (Where Would It Be Coming From)

    For the last 4 or so years I have had an oil leak draining down the passenger side rear of the motor on my 94 K2500HD 6.5L Diesel. It leaks down the side of the bell housing on the starter then to the ground. I am trying to figure out potential sources of the leak. I can see some oil residue in the valley toward the rear of the engine as well. At first I was thinking it could be the OPS, but I have read that it located on the driver side, so I am thinking that is not the issue. I am almost positive it is not the valve cover either as I had my transmission and bell housing off about 4 months ago and I had a pretty good view of the back side of the valve cover. It appeared to be coming from somewhere up in the valley of the motor at the rear. Can anyone point me at some common items that may be the source of this oil leak.

  2. #2
    Join Date
    Jan 2005
    Location
    Denville,New Jersey
    Posts
    424

    Default

    The fuel injector return lines on mine caused that exact symptom as you described. Get yourself a complete kit, as it has all of the pieces needed.These are made of heat and fuel resistent material which will last many years. Since you are new here you may want to fill in the information in your signiture which appears at the bottom of all posts. You can see an example of it at the bottom of my reply. Let me be the first person here to welcome you to The Diesel Page!
    94 Chev Blazer, 6.5TD, 3.42, 4WD,Gear drive,,Remote FSD behind drivers headlight,,Mobil 1 in difs and trans,Rotella 30W, Over a quarter of a million miles !! Member -1.94 club.

  3. #3
    Join Date
    Apr 2001
    Location
    Newberg Oregon
    Posts
    12,282

    Default

    Crawl up into the engine bay and peek down into the valley area and get a light in there.

    The IP could be seeping oil where it bolts to the front cover.

    OIL AND FUEL CAN DRAIN down the hole in the back of the valley, but this will drip out of the hole at the lower bell housing cover.

    Dripping off the RH rear side almost has to be a VC leaking.

    The turbo oil drain line runs down the front side and into the block... possibly blowing back ???

    Can you get it on a hoist and get a good peek at it from the bottom ???
    (1) 1995 Suburban 2500 4x4
    (1) 1997 Astro
    (1) 2005 Suburban (Papa Smurf)
    THIS IS BOW TIE COUNTRY

  4. #4
    Join Date
    Mar 2017
    Location
    ND
    Posts
    20

    Default

    Quote Originally Posted by Warren96 View Post
    The fuel injector return lines on mine caused that exact symptom as you described. Get yourself a complete kit, as it has all of the pieces needed.These are made of heat and fuel resistent material which will last many years. Since you are new here you may want to fill in the information in your signiture which appears at the bottom of all posts. You can see an example of it at the bottom of my reply. Let me be the first person here to welcome you to The Diesel Page!
    Thanks for the welcome. I am almost certain it is actually oil and not fuel, but I will smell a sample tonight and see if there is a Diesel odor to it. How much of a pain is it to change out those lines? They mush be packed back in there.
    (1) 94 K2500HD Silverado 146,000 Miles/5 Speed Manual Trans./Heath PMD Relocate/Leroy Diesel PMD with #9 Resistor/4" Straight Pipe/Cooling Fan and Clutch Upgrade/ 80 Degree Thermostat/High Idle Mod/Cold Air Intake (not so cold)/Pyro,Boost,Trans Temp AutoMeter Gauges/New Injectors/Glow Plugs @ 108,000
    (2) 15 K2500HD LML/LTZ/18,500 Miles/ Northland Bumper Gill Guard/Replacement Bumper/Bushwacker OE Fender Flares/DuraFlap 14" Mudflaps/PPEI ECM and TCM Tunes/AirDog II 4G 165 Lift Pump/MBRP 3" Downpipe/FloPro 5" Straight Pipe/Deviant EGR Blocker Plates/EDGE CTS 2 Monitor with EDGE Pyro Probe

  5. #5
    Join Date
    Mar 2017
    Location
    ND
    Posts
    20

    Default

    Quote Originally Posted by Robyn View Post
    Crawl up into the engine bay and peek down into the valley area and get a light in there.

    The IP could be seeping oil where it bolts to the front cover.

    OIL AND FUEL CAN DRAIN down the hole in the back of the valley, but this will drip out of the hole at the lower bell housing cover.

    Dripping off the RH rear side almost has to be a VC leaking.

    The turbo oil drain line runs down the front side and into the block... possibly blowing back ???

    Can you get it on a hoist and get a good peek at it from the bottom ???
    Thanks for the reply. When I had the transmission off a while ago I could see that it appeared to be coming from the valley somewhere and following the top of the bell housing down the passenger side. I could also see some residue where it looked like it followed the head gasket seam around the back of the motor and down the rear. I do have a leak on the turbo oil return line due to a bad gasket and I have ruled it out as the cause of this leak.
    (1) 94 K2500HD Silverado 146,000 Miles/5 Speed Manual Trans./Heath PMD Relocate/Leroy Diesel PMD with #9 Resistor/4" Straight Pipe/Cooling Fan and Clutch Upgrade/ 80 Degree Thermostat/High Idle Mod/Cold Air Intake (not so cold)/Pyro,Boost,Trans Temp AutoMeter Gauges/New Injectors/Glow Plugs @ 108,000
    (2) 15 K2500HD LML/LTZ/18,500 Miles/ Northland Bumper Gill Guard/Replacement Bumper/Bushwacker OE Fender Flares/DuraFlap 14" Mudflaps/PPEI ECM and TCM Tunes/AirDog II 4G 165 Lift Pump/MBRP 3" Downpipe/FloPro 5" Straight Pipe/Deviant EGR Blocker Plates/EDGE CTS 2 Monitor with EDGE Pyro Probe

  6. #6
    Join Date
    Jan 2020
    Location
    Trabuco Canyon, CA.
    Posts
    18

    Default

    I too have the same scenario on my '94 K2500, 324K. I'm replacing head gaskets this week. Passenger head gasket removed (failed at front water jacket) and indicates oil seepage above rear most lifter/pushrod cavity. The block in that area is shaded in oil, whereas the remaining areas appear in normal mill finish. I am convinced this is the culprit. I too thought it had to be VC's; not so. They were snug and sealed. I may be proven wrong when I run the engine soon. I'll post a follow-up.

  7. #7
    Join Date
    Dec 2009
    Location
    In the North
    Posts
    700

    Default

    Quote Originally Posted by 6.5_Diesel View Post
    Thanks for the reply. When I had the transmission off a while ago I could see that it appeared to be coming from the valley somewhere .
    Op sending unit,.?
    1999 chev suburban C2500
    300,000 mi

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •