Author Topic: 2004 chevy express HVAC  (Read 1755 times)

Offline Irish_Alley

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2004 chevy express HVAC
« on: December 17, 2018, 07:55:49 PM »
my father who has Parkinsons is down a few states away and is having issues with his heater. one of my brothers replaced his broken heater core and after that they cant seam to get hot air to the front vents. it has the climate control for the rear of the van and they work fine. my issue is im trying to help him over the phone and im thinking it has something to do with the blender door as they say bother heater core hoses are getting warm. but i cant seam to find a location for the blender door and dad cant really get round like he used to and we're depending on my step mom to do most things. so if someone has some details about the express HVAC that would be wonderful
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline VileZambonie

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Re: 2004 chevy express HVAC
« Reply #1 on: December 18, 2018, 04:52:41 AM »
What was broken about the heater core? Was the radiator replaced? Is the bypass valve installed correctly? Is the thermostat good? Did they bleed the system?

Read this bulletin:

#PIP3267C: DTC P0128 Or Engine Will Not Reach
Operating Temperature - (Dec 16, 2011)
This PI was superseded to update model years. Please discard PIP3267B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Possible DTC P0128 or the engine will not reach operating temperature after a radiator
replacement. Some replacement radiators may be missing a restriction orifice that is built into the
right side radiator tank. The restriction orifice is molded into the nipple that feeds the radiator
surge tank.
The engine may not reach operating temperature, or set DTC P0128 due to excessive coolant flow
to the radiator surge tank.
Recommendation/Instructions:
If SI diagnostics have been completed for DTC P0128 and no problem was found, contact the
customer to discuss radiator replacements, and check the vehicle history for previous radiator
replacements. If the radiator was replaced for a cooling system concern, or replaced during a front
end body shop repair, it may be missing the radiator surge tank restriction orifice. Remove the
surge tank hose from the radiator and visually inspect the radiator tank nipple that feeds the surge
tank. If the radiator is missing the surge tank restriction orifice there will be an increased amount
of coolant flow to the surge tank. Excessive coolant flow may induce DTC P0128.
If the radiator surge tank restriction is missing, the radiator needs to be replaced with the proper
replacement radiator as listed in the GMSPO parts catalog.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition
exhibited is resolved without completing every step, the condition
exhibited is resolved without completing every step, the remaining steps do not need to be
performed.
,                           ___ 
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              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Irish_Alley

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Re: 2004 chevy express HVAC
« Reply #2 on: December 18, 2018, 03:30:27 PM »
as far as i know it was leaking. dont think the rad was replaced but again was there to verify anything. ill get more info
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline VileZambonie

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Re: 2004 chevy express HVAC
« Reply #3 on: December 18, 2018, 04:11:55 PM »
Electrolysis is a big problem in these as well. It should be checked before just calling it a day
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10