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Thread: Losing coolant

  1. #1
    Join Date
    Jan 2006
    Location
    South Milwaukee, WI
    Posts
    245

    Angry Losing coolant

    '01 DMax, LB7 w/400,600 miles
    Head gaskets replaced ~62K miles earlier. Water pump replaced ~200K miles.
    Coolant was a bit low, so about a 1/2 pint (give/take) was added. Engine was left to run ~1/2 hour in 0 degree temps. Within that 1/2 hour, the coolant developed too much pressure and was pouring out of the coolant bottle. Added about 1.5 gallons, ran the vehicle and had to add a little more several times. I'm currently consuming a bit of coolant with every 30 mile (+/-) trip on the highway. I've watched the coolant temp gauge in the cab go from ~180 degrees to 160 and back in the course of a couple of miles (air temperature from the heater dropped and rose accordingly). I see nothing dripping on the ground as of late; yet, level seems to drop with mileage.

    Took this in to the dealership- they report nothing found. State it could be an air pocket that may be developing in the head (suggesting a questionable head gasket???). Topped off the coolant and ran a 50+ mile round trip and watched the temp gauge vary from about 170 to 210 and back within a 5 minute window of time. Looking for tips- thermostats going bad (they haven't been changed in quite some time)? Water pump? Head gasket failure after only 62K miles? The dip stick shows no foaming and the oil appears golden (not "orange"- not to say there isn't any getting there). No smoke from the tail pipe (except the normal smoke you'd expect under acceleration at 0 degrees air temp and lower).

    Any input would help.
    "Chessy56"
    So. Milwaukee, WI
    '01 2500HD, LB7, ~440K miles
    "Stock" engine. Dual fuel filtration system with Kennedy lift pump, BF Goodrich Commercial T/A Traction tires (sold to a dude from Texas- it's living a warmer life just fine down there now!).

    '17 2500HD, L5P (Happy Birthday/Merry Christmas to me!!!) Currently bone stock, 120K miles.

    "Socialism is a philosophy of failure, the creed of ignorance and
    the gospel of envy. Its inherent virtue is the equal sharing of misery."
    Winston Churchill

  2. #2
    Join Date
    Dec 2000
    Location
    Hawaii/Arizona
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    259

    Default Coolant pressure cap.

    The first thing I would try is to replace the coolant pressure cap. For years my 2006 LBZ would not stay full of coolant until I replaced the pressure cap. Since I replaced the cap three years ago it has not lost another drop of coolant. It is an inexpensive item that is often overlooked by mechanics.

    One of Jim's old DP articles addresses the pressure cap issue and that is what lead me to change my cap.

    Good luck
    John
    *2006 Chevy, 3500, 4X4, DRW, (LBZ) D/A, CC, LT, 252K Miles, 19.5" Wheels, Mag Hytec Transmission Pan and Differential Cover, SS Grill Guard, Racor 2 micron aux fuel filter, 100 Gallon Aux Fuel Tank, using Edge Evolution, Predator Diablosport, Kennedy ECM tune, Fitch Fuel Catalyst.

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    *2005 Jeep, Liberty, CRD (diesel).
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  3. #3
    Join Date
    Mar 2000
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    10,792

    Default

    The fact that it rapidly built pressure and puked tells me head gasket. Did you stud it?
    Kennedy Diesel-owner
    More than just a salesman-I use and test the products that I sell on a daily basis!
    Superflow Lie Detector in house
    2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
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    2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
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  4. #4
    Join Date
    Dec 2002
    Location
    Teton Valley, Idaho
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    Default

    What did the dealer do and look at to tell you "nothing found"? What does a pressure test show?

    I've had a water pump impeller spin itself loose from its drive shaft on an intermittent basis that caused the problems you loosely describe: spiking water temps, hot/cold temps from the heater (cuz coolant wasn't being pushed through the core like it should've been. A new water pump solved it, but not before I replaced the passenger side head gasket thinking that was the problem.

  5. #5
    Join Date
    Jan 2006
    Location
    South Milwaukee, WI
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    245

    Default Coolant issue

    Heard from the dealership- don't know what tests were done, but they believe it is a blown head gasket. Pisses me off that I'll be dumping another $5K into this after only 62K miles. They believe exhaust (compression???) pressure is making its way into a coolant port. Don't know which side. JK: Don't believe they did a stud job- (if I understand your post, I believe they used new OEM head bolts- torqued to their yield point????).

    Question now is whether they can replace the gaskets without doing any machining to the heads. Service tech states that they can only do one cut on these heads- otherwise, I'd be looking at another $3K for replacement heads. What are your thoughts? Is there a better head gasket than OEM? Any thoughts on just replacing the head gaskets without further head work?

    I saw a post on these pages sometime back- coolant system was being pressurized by a bad head gasket- same result as what I'm seeing. Maybe time to retire the old girl to hunting/light hauling duty and get something different for everyday running. Still putting 600/week on it!
    "Chessy56"
    So. Milwaukee, WI
    '01 2500HD, LB7, ~440K miles
    "Stock" engine. Dual fuel filtration system with Kennedy lift pump, BF Goodrich Commercial T/A Traction tires (sold to a dude from Texas- it's living a warmer life just fine down there now!).

    '17 2500HD, L5P (Happy Birthday/Merry Christmas to me!!!) Currently bone stock, 120K miles.

    "Socialism is a philosophy of failure, the creed of ignorance and
    the gospel of envy. Its inherent virtue is the equal sharing of misery."
    Winston Churchill

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

    Arrow

    Chessy,
    I'd wait till the suspect parts have been removed before making many plans. Have whoever does the work to carefully look at the head gaskets once the heads have been removed. You're looking for confirmation of the diagnosis.

  7. #7
    Join Date
    Jan 2006
    Location
    South Milwaukee, WI
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    245

    Default Confirmation of diagnosis

    MP: presuming they do find that the head gasket is indeed bad.... This may be premature, but they'll probably want a quick answer from me as they won't want to tie up their bay for too long. What questions should I be asking, if any? What would you be concerned with?

    Thanks for the quick reply!
    Chessy (Gary)
    "Chessy56"
    So. Milwaukee, WI
    '01 2500HD, LB7, ~440K miles
    "Stock" engine. Dual fuel filtration system with Kennedy lift pump, BF Goodrich Commercial T/A Traction tires (sold to a dude from Texas- it's living a warmer life just fine down there now!).

    '17 2500HD, L5P (Happy Birthday/Merry Christmas to me!!!) Currently bone stock, 120K miles.

    "Socialism is a philosophy of failure, the creed of ignorance and
    the gospel of envy. Its inherent virtue is the equal sharing of misery."
    Winston Churchill

  8. #8
    Join Date
    Dec 2002
    Location
    Teton Valley, Idaho
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    1,873

    Default

    If they're dug in deep enough to replace the head gaskets, another half hour will get you a new water pump... It was a seriously sinking feeling to button up after replacing the passenger side head gasket only to have the engine get too hot on startup due to the pump impeller not impelling. Looking at the impeller with the lower radiator hose removed (used a scope) showed that it wasn't turning when a friend hit the starter.

    Ask the dealer to check the water pump. Physically check it. BEFORE pulling the heads. They'll be draining the coolant first thing anyway.

  9. #9
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    Default

    The OE bolts in my opinion are the key contributing factor in the gasket failures. The heads just move too much and the fire ring collapses. Now the latest gaskets no longer have a fire ring which I also don't care for.

    We use the latest version old style gaskets and studs. Skim cut the heads which should only take .002-3" to get them clean. A second cut is not that big a deal.
    Kennedy Diesel-owner
    More than just a salesman-I use and test the products that I sell on a daily basis!
    Superflow Lie Detector in house
    2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
    2005 Chev K3500SRW D/A CC Long LT(SOLD)
    2007 Chev K2500 Classic EC Short LT (Sold)
    2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
    2016 GMC K3500SRW D/A CC short LTZ

    Custom tuning in house using EFI Live tuning software!

  10. #10
    Join Date
    Jan 2006
    Location
    South Milwaukee, WI
    Posts
    245

    Default OE Bolts/head gaskets

    John-
    Thanks for the info on the Hd gaskets and OE bolts. I passed the information on to my service tech at Braeger Chevy (Milwaukee). Can't comment on what they've found so far as I haven't heard that they indeed confirmed the gasket failure. I'll post my findings/results as I learn of them. Appreciate the help.
    Chessy (Gary)
    "Chessy56"
    So. Milwaukee, WI
    '01 2500HD, LB7, ~440K miles
    "Stock" engine. Dual fuel filtration system with Kennedy lift pump, BF Goodrich Commercial T/A Traction tires (sold to a dude from Texas- it's living a warmer life just fine down there now!).

    '17 2500HD, L5P (Happy Birthday/Merry Christmas to me!!!) Currently bone stock, 120K miles.

    "Socialism is a philosophy of failure, the creed of ignorance and
    the gospel of envy. Its inherent virtue is the equal sharing of misery."
    Winston Churchill

  11. #11
    Join Date
    Mar 2000
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    Loyal WI US
    Posts
    10,792

    Default

    When opened up the LB7 injector line corrosion issues will be revisited as well. They will not know anything about any other gasket besides the cheap 3 layer LML gasket.
    Kennedy Diesel-owner
    More than just a salesman-I use and test the products that I sell on a daily basis!
    Superflow Lie Detector in house
    2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
    2005 Chev K3500SRW D/A CC Long LT(SOLD)
    2007 Chev K2500 Classic EC Short LT (Sold)
    2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
    2016 GMC K3500SRW D/A CC short LTZ

    Custom tuning in house using EFI Live tuning software!

  12. #12
    Join Date
    Jan 2006
    Location
    South Milwaukee, WI
    Posts
    245

    Default update-

    Head gasket failure confirmed- leak was spotted at the #7 cylinder. Tech states that the gasket had to be peeled off- didn't seem to have shifted (can't say it shifted when it was initially installed). They didn't seem to feel the issue was with the gasket, which leaves me wondering what the failure mode really was. There has to be one!

    Inquired into putting studs in- it wouldn't have been a problem if they had somewhere to quickly order them from. In the interest of getting this thing back on the road, (and out of their bay), I told them to use what they had in stock (presumably, the OEM bolts; and most likely, OEM gaskets). It's at the point where I may relegate this truck to hunting/hauling and get something more fuel efficient for the 600 weekly mile commutes. At least they'll be in a position to quickly replace the pressure regulator on the pump- it has been surging and throwing codes on occasion.

    I did put new injectors AND new pipes in about 16 months back. With luck, contamination from corrosion will be minimized. We'll see. All of my service work and mileage is logged.

    If I keep this puppy for another few hundred thou miles and need another set of head gaskets, I might tackle the job myself. I'd be better off moving it along and looking for something a little newer.
    Last edited by chessy56; 01-21-2016 at 16:13. Reason: addition....
    "Chessy56"
    So. Milwaukee, WI
    '01 2500HD, LB7, ~440K miles
    "Stock" engine. Dual fuel filtration system with Kennedy lift pump, BF Goodrich Commercial T/A Traction tires (sold to a dude from Texas- it's living a warmer life just fine down there now!).

    '17 2500HD, L5P (Happy Birthday/Merry Christmas to me!!!) Currently bone stock, 120K miles.

    "Socialism is a philosophy of failure, the creed of ignorance and
    the gospel of envy. Its inherent virtue is the equal sharing of misery."
    Winston Churchill

  13. #13
    Join Date
    Apr 2014
    Location
    Tampa, Florida,USA
    Posts
    22

    Default

    If you decide to have it repaired, make sure to use only oem kit specially the head gasket and also drain and flush the whole cooling system.

  14. #14
    Join Date
    Mar 2000
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    Loyal WI US
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    Default

    What you report is typical. Fire ring fails and collapses to the inside ie gasket no longer round. The #7 cylinder is also VERY common. They fail this way with BOLTS. I have never seen one repeat with studs including HP big boost applications.
    Kennedy Diesel-owner
    More than just a salesman-I use and test the products that I sell on a daily basis!
    Superflow Lie Detector in house
    2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
    2005 Chev K3500SRW D/A CC Long LT(SOLD)
    2007 Chev K2500 Classic EC Short LT (Sold)
    2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
    2016 GMC K3500SRW D/A CC short LTZ

    Custom tuning in house using EFI Live tuning software!

  15. #15
    Join Date
    Dec 2002
    Location
    Teton Valley, Idaho
    Posts
    1,873

    Default

    Is the number 7 cylinder the back passenger side?

    If so, +1 to what Kennedy just said. That's the one that failed on mine a couple of years ago.

  16. #16
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    Feb 2000
    Location
    Montana
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    11,382

    Default

    What you're looking for.... Leaks usually leave a track across a portion of the head gasket, or you may see some discoloration across the leak path if combustion pressure is finding its way into the cooling system.

    If a head gasket leak is the primary suspect, I'd want some sort of validation for that diagnosis. Otherwise, the real cause could rear its ugly head after you've paid a lot of money for what may be unnecessary parts replacement.

    Combustion gases can be measured in the cooling system using a special gas measuring tool that mechanics have access to. They just sniff the surge tank with the cap removed. Easy...

  17. #17
    Join Date
    Jan 2006
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    South Milwaukee, WI
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    245

    Default leaks.....

    So- the truck has got new head gaskets (again) and this time, I picked up studs and had the dealership install them with the rebuild. Also had them install a new pressure regulator as the engine had been surging a bit over the past couple of years and occasionally threw a code because of it.

    Not seeing any leaks, and the reservoir bottle level seems to be stable. However, I'm accustomed to feeling some pressure on the upper radiator hose, especially after some 270 miles that has been put on it since picking it up yesterday. I can squeeze the hose w/o any pressure being felt even after the engine has come up to 180 deg. Kind of wondering about that. Any thoughts on the lack of residual pressure? (It used to always retain some amount of system pressure, even after sitting over night.)
    "Chessy56"
    So. Milwaukee, WI
    '01 2500HD, LB7, ~440K miles
    "Stock" engine. Dual fuel filtration system with Kennedy lift pump, BF Goodrich Commercial T/A Traction tires (sold to a dude from Texas- it's living a warmer life just fine down there now!).

    '17 2500HD, L5P (Happy Birthday/Merry Christmas to me!!!) Currently bone stock, 120K miles.

    "Socialism is a philosophy of failure, the creed of ignorance and
    the gospel of envy. Its inherent virtue is the equal sharing of misery."
    Winston Churchill

  18. #18
    Join Date
    Dec 2002
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    Teton Valley, Idaho
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    Default

    If a closed system like your engine cooling system starts with no pressure when it is cold, it should end with no pressure after cooling down after a heat cycle. Sounds to me like the mechanic did it right.

    You were feeling residual pressure before the repair because the engine was adding volume (gasses) to the cooling system via a leaking head gasket.

  19. #19
    Join Date
    Jan 2006
    Location
    South Milwaukee, WI
    Posts
    245

    Default no pressure

    Oxidation: What you mention sounds reasonable, but I've noted pressure holding on the cooling system for years. In fact, I was surprised to feel this residual pressure long before my original head gaskets or sprays were replaced. I questioned it, even with the engine "cold", but was told that this is common for the Duramax. In this instance, I developed sufficient pressure to blow coolant out of the reservoir bottle. I never had this happen before.

    I'll be taking another 250 mile highway run in a day or two. We'll see how it does and report my findings. Thanks.
    "Chessy56"
    So. Milwaukee, WI
    '01 2500HD, LB7, ~440K miles
    "Stock" engine. Dual fuel filtration system with Kennedy lift pump, BF Goodrich Commercial T/A Traction tires (sold to a dude from Texas- it's living a warmer life just fine down there now!).

    '17 2500HD, L5P (Happy Birthday/Merry Christmas to me!!!) Currently bone stock, 120K miles.

    "Socialism is a philosophy of failure, the creed of ignorance and
    the gospel of envy. Its inherent virtue is the equal sharing of misery."
    Winston Churchill

  20. #20
    Join Date
    Dec 2002
    Location
    Teton Valley, Idaho
    Posts
    1,873

    Default

    Just for kicks:
    When the engine is cold (before you start it in the morning) open up the cooling system expansion tank cap to be positive that there is zero residual pressure. Run the truck for your 250 miles, or at least enough to get the engine up to normal operating temperature, and give the upper radiator hose a squeeze. Next morning, when the engine is cold again, give the hose another squeeze (should feel like zero pressure). Open up the tank cap again, and you shouldn't hear any pressure going in or coming out (assuming that the ambient air temperature is the same as it was when you previously opened the cap).

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