Results 1 to 20 of 22

Thread: Duramax coolant flow diagram?

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1

    Default Duramax coolant flow diagram?

    Anyone have access to a good pictorial of the Duramax cooling system, showing thermostats, pump, radiator, etc and detailing coolant flow? If so, could you scan and post it - or email it to mark_rinker@hotmail.com?

    Thanks in advance...
    2011 Chevrolet Tahoe 5.3L daily driver
    • Previous owner of two 1994 6.5L K3500s, '01, '02, and '05 6.6L K2500s, '04 C4500, '06 K3500 dually, '06 K3500 SRW, '09 K3500HD SRW, '05 Denali
    • Total GM diesel miles to date : ~950K

  2. #2
    Join Date
    Feb 2000
    Location
    Montana
    Posts
    11,382

    Default

    Coolant travels from the water pump to the engine oil cooler, into the aluminum bellhousing adapter, into both cylinder banks at the back of the engine, then up into the heads, then to the thermostat housing.

    Jim

  3. #3

    Default

    Thanks for the description, JK.

    You have mentioned in a past that one of the reasons for two thermostats is redundancy.

    Are they 'serial' in their restriction of coolant flow, or 'parallel'?
    2011 Chevrolet Tahoe 5.3L daily driver
    • Previous owner of two 1994 6.5L K3500s, '01, '02, and '05 6.6L K2500s, '04 C4500, '06 K3500 dually, '06 K3500 SRW, '09 K3500HD SRW, '05 Denali
    • Total GM diesel miles to date : ~950K

  4. #4
    Join Date
    Mar 2006
    Location
    Phoenix, AZ
    Posts
    144

    Default

    parallel, and staggered by 5 degrees. One of them is a bypass stat. When it "opens" it closes off bypass flow.

    If you squeeze your top hose, you will hear a rattling sound. This is the vapor purge mechanism "jiggly balls" in the rear stat.

  5. #5

    Default

    Interesting. Is there a safegaurd to keep the two from being installed reversed?

    My '01 pressurizes the cooling system, but only in cold weather (bypass mode?). Wondering what the effect of removing one or both thermostats would be and continuing to run this high mile engine for another 50K or so, and repowering in the fall before cold weather sets in, creating the coolant loss issue described in other threads.

    Would you pull one, or both?
    Last edited by Mark Rinker; 03-31-2007 at 12:23.
    2011 Chevrolet Tahoe 5.3L daily driver
    • Previous owner of two 1994 6.5L K3500s, '01, '02, and '05 6.6L K2500s, '04 C4500, '06 K3500 dually, '06 K3500 SRW, '09 K3500HD SRW, '05 Denali
    • Total GM diesel miles to date : ~950K

  6. #6
    Join Date
    Feb 2000
    Location
    Montana
    Posts
    11,382

    Default

    The stats are physically different. Would be hard to install wrong....

    Jim

  7. #7
    Join Date
    Mar 2006
    Location
    Phoenix, AZ
    Posts
    144

    Default

    Quote Originally Posted by Mark Rinker
    Interesting. Is there a safegaurd to keep the two from being installed reversed?

    My '01 pressurizes the cooling system, but only in cold weather (bypass mode?). Wondering what the effect of removing one or both thermostats would be and continuing to run this high mile engine for another 50K or so, and repowering in the fall before cold weather sets in, creating the coolant loss issue described in other threads.

    Would you pull one, or both?
    In theory, if you pull one or both, then the lower rad hose would be subject to suction collapse at high rpm.

    The front stat cannot be installed in the rear, but I do believe the rear will fit the front housing. If that were to occur (wrong stat in the front) then the bypass would never be closed off, radiator flow would be reduced, and overheat would be the result on a workload session.

    But I can't see how running without a stat can be less stressful to a high mileage vehicle.
    Michael 04.5 SRW LLY

    custom stock intake, upsized boost tubes, Pre-turbo WMI, EFILive custom tune, Aerotech Scan Gauges.

    Go Smokeless!

Posting Permissions

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