Duramax Diesels Forum Truck of the Week
Old 05-07-2020, 09:42 PM
Nitro2020 Nitro2020 is offline
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Location: Washington
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Default Head gaskets or something else?

My local shop just informed me that my 2004 lb7 with 183k miles on it needs head gaskets. So far the only symptom has been pressure in the coolant overflow tank. I already had injectors done about 20k miles ago, as well as the water pump about 5k miles ago. The job is just over $6,600 for head gaskets (including studs). I have also been told from family to look into getting a rebuilt long block motor shipped and have it replaced. That would be about $8,000 to do.
Is one more worth it? I have been told by a couple shops that this is a solid engine and insists that I have no need to do an engine swap.
The other option is to trade it in as is for another used duramax (we need a truck) but we have been told the trucks after this one have more issues and that this is the most desired truck.
Any advice on what route to go?

Also, upon further reading on this forum, could the problem be something else, or even nothing since the truck is running good with no smoke? I have added about 1/2 gallon of coolant since water pump replacement. Overflow tank threw up some coolant after a 400 mile drive (half of which towing 4500 lb trailer) and sitting for a couple days. Replaced overflow cap, then drove 50 miles locally with no trailer. Overflow tank hissed with coolant rising a little when opening cap (after sitting overnight). Ideas on my next step?
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Old 05-07-2020, 09:55 PM
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torqued2dmax torqued2dmax is offline
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After driving it make sure the cap is tight then let it set over night check the upper rad hose if it is hard then you got problems .
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Old 05-07-2020, 11:38 PM
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$6k for a head gasket job? Any way you could do it yourself? And I'd skip the studs too

No need to do an engine swap. I'd lean towards the head gaskets being bad, when I've seen an injector cup come loose they'll leak pressure into the coolant much worse than what you described. But others may have a different experience, there's only so many ways to pressurize the coolant.
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Old 05-08-2020, 04:28 AM
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If you didnt "burp" the cooling system when you did the w/p, you can easily add that much coolant to get it full. If the upper hose isnt hard like Torque says, then you probably do not have an issue with h/g's.
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Old 05-08-2020, 08:44 PM
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6600 is steep for a headgasket job imo. Where are you located?
Also i agree with tom about burping the system. If the upper rad hose isnt hard then its usually not head gaskets.
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Old 05-09-2020, 07:24 AM
KyleC4 KyleC4 is offline
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6k? Wow. I’m not charging enough lol. Follow what these guys have said about radiator hose after over night sit. And if injector cups were leaking, I always see some intermixing of coolant and oil
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Old 05-09-2020, 07:50 AM
Nitro2020 Nitro2020 is offline
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The radiator hose was stiff (squeezable with effort) after sitting, but not rock hard. So far, 6k is the cheapest I have found. The other 2 shops I called wanted over 8k for the head gasket job. I do not have the time, tools, or experience to do the work myself. I am located in the Gig Harbor area of Washington.
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Old 05-23-2020, 07:04 PM
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Mxz8002003 Mxz8002003 is offline
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Its possible you could have an injector cup leak. Ive seen it on my old mans lb7, though it was hg end up being a couple cups..
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Old 05-28-2020, 10:03 PM
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What shop in gig harbor? When the time comes, I'll be doing the work myself.

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