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Gary
Gary, GMC Technician
Category: GM
Satisfied Customers: 17179
Experience:  15 years gm master tech/15 years ASE master tech
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My 02 GMC Envoy is overheating. I replaced the water pump,

Customer Question

My 02 GMC Envoy is overheating. I replaced the water pump, thermostat, radiator, both hoses, overflow jug, and a professional radiator flush. There's no blue smoke or any other color smoke coming from the exhaust pipe. I'm at the end of my rope with this truck. What can it be?
Submitted: 11 months ago.
Category: GM
Expert:  Gary replied 11 months ago.

Welcome! My name is ***** ***** I will do my best to assist you with this problem.

Expert:  Gary replied 11 months ago.

will it over heat at idle or only when driving it ?

any codes set at all ?

Customer: replied 11 months ago.
No codes.
Expert:  Gary replied 11 months ago.

will it over heat at idle ?

or only when driving it ?

Customer: replied 11 months ago.
Man, this truck is driving me broke but I need it for work.
Expert:  Gary replied 11 months ago.

when will it over heat ?

Customer: replied 11 months ago.
driving at 60+ mph, a/c or heat is on
Expert:  Gary replied 11 months ago.

at idle it is fine ?

only at speed when driving ?

Customer: replied 11 months ago.
Customer: replied 11 months ago.
the engine goes into Idle too. The fan gets really loud until I stop.
Expert:  Gary replied 11 months ago.

and there is nothing blocking the front of the radiator and the ac condenser fins are all cleaned out good ?

is the fan clutch new ?

Customer: replied 11 months ago.
nothing blocking front of radiator. condenser fins are clean. the fan runs fine.
Expert:  Gary replied 11 months ago.

have you tested the coolant for emissions in it with the chemical test called block tester most auto parts stores sell ?

Customer: replied 11 months ago.
I took it to Firestone and wasted $260. I doubt that they did that.
Expert:  Gary replied 11 months ago.

if it has a new radiator and water pump and the coolant if full and it has been flushed and you said the fan clutch is good as you say it is the only thing left is a flow issue sometimes caused by a head gasket allowing some compression into the cooling system which will slow down the flow of the coolant and cause an over heating issue

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Customer: replied 11 months ago.
wouldn't they catch that when they did the Engine Compression Test?
Customer: replied 11 months ago.
are you gone.
Expert:  Gary replied 11 months ago.

i am here

Expert:  Gary replied 11 months ago.

it takes a few to type back

Expert:  Gary replied 11 months ago.

no a compression test will not show it

Customer: replied 11 months ago.
is there any test that I could do to see if the heads are a problem? I was told to look for Blue Smoke.
Expert:  Gary replied 11 months ago.

it can be showing nothing out of the tail pipe for this type of issue

that is why they sell the block tester which will measure the coolant for any emissions in the coolant

at this point you have covered everything else to cause this issue

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Expert:  Gary replied 11 months ago.

how are you making out ?

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you can always get me back for FREE for any follow up any time with this question even after you rate me here at Justanswer

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