Enigne Overheating

My 04 Envoy is doing the same thing. I am in New Mexico and replace everthing as well. 2 weeks in the shop and still it overheats when the ac is on. Could a valve/ head be causing a problem. I read that some removed the head, cleaned and ground the valves and now seems to be ok. Yes I am a women, who does not have a clue about auto repairs, This is getting costly!

Hey,

This car had a problem with the head gaskets which can be detected by using a chemical test, Here is a guide that will show you how to do it.

https://www.2carpros.com/articles/head-gasket-blown-test

Please run this test and get back to us so we can continue helping you.

Best, Ken

2004 GMC Envoy 6 cyl Four Wheel Drive Automatic 94000 miles

My Envoy has a P0128 code. The engine will run cool sometimes while driving, but when I am sitting still the engine will overheat. Sometimes it will run normal. What is the cause of this?

If it only happens when you are sitting still, chances are the cooling fan isn't working all of the time. Do you hear it turn on when it overheats?

This guide can help

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please run down this guide and report back.

Transmission problem
2004 GMC Envoy 6 cyl Two Wheel Drive Automatic 75000 miles

if my engine was overheated for several minutes by not having the cap on, will it ruin the transmission fluid?

Unless the tranny cooler compartment is leaking internally mixing with the coolant.

Engine Cooling problem
2004 GMC Envoy 6 cyl Four Wheel Drive Automatic 97,000 miles

my car overheats after i go about 20-25 miles and i can smell coolant a little bit. when the engine cools, and i check the water level in the radiator, and it still has water. what is causing it to overheat?

Hello, my car keeps running hot. I first replaced the thermostat and then it still was running hot so I replaced the water pump. and had radiator flush and still running hot. My car it is not leaking fluid but when it get hot I pour water in the radiator to cool it but no leaks what wrong.

Hello Slim,

If I understand you correctly you have no leaks but the radiator keeps getting low? If so you might have a blown head gasket, here is a test you can use to see if this is your problem which would make the car over heat.

https://www.2carpros.com/articles/head-gasket-blown-test

Please run this test and get back to us so we can continue helping you.

Best, Ken

I feel like I am going over and over this post, but I am having the same problem and I am not sure where to go next. Car overheated on the way back from Kansas City. I kept pulling over and letting it cool back off before going to the next exit and repeating it over and over again. During this I noticed that the coolant was not leaving the overflow bottle and going back into the engine. Finally on one of my last stops I splashed some water into the engine and I heard a pop and all the fluid from the overflow went into the radiator and the car instantly cooled off and I was able to make it back to the house.

I pulled the codes off my car and found that the fan clutch was under speed. Pulled the fan clutch and the wires were all burned out so while I was in there I replaced the fan clutch and the water pump. If you do one you should do them both, plus when I pulled it the water pump was warped. So drove it for a few days on short trips and when I went to pull my friends car on my trailer to the mechanic the car overheated on the way back. Pulled over waited for it to cool off and then was able to limp it home. Pulled the thermostat and it seems good but I replaced it anyways. Started it up and ran it to get it up to operating temperature and the temp started to rise again and the overflow is still not releasing into the engine.

I am thinking that it could be the radiator but figured I would search online and see any of y’all have any ideas. Basically I replaced everything except the radiator itself. All the parts needed to be replaced, minus the thermostat. Anyone have an idea?

Yes it could be the radiator causing the issue. I would look inside and outside of the radiator fins and cooling tubes for blockage also use a garden hose to blast water in the opposite direction of the air flow to the radiator cooling fins.

Next I would test the engine for a blown head gasket which does not always result in coolant in the engine oil.

Here are two guides to help:

https://www.2carpros.com/articles/engine-overheating-or-running-hot

and

https://www.2carpros.com/articles/head-gasket-blown-test

Please run down these guides and report back.

Cheers, Ken

Replaced water pump, thermostat, coolant disappearing someplace making car over heat. No coolant in the oil. clean and clear, do not believe there is oil in coolant. A/C and heater work. no visible leaks. Can drive it the temperature is fine, but if I slow down or I am stopped for a short period of time the temperature gauge starts to rise above normal (about 210-220 degrees) hotter if I don't turn on the heat full blast. But drive for a bit the car cools almost to normal temperature. No noticeable white smoke etc from exhaust. where should I start looking first? There was a slight intake manifold leak outside motor, my so just replaced. Before taking it to my son to repair gasket I checked radiator level. added about half cup of 50/50. Drove about fifteen miles to his house. When he removed the radiator hose there was nothing in it he said. There are never any visible spots on the ground or in the engine compartment. He did the repairs. Drove it, it continues to overheat. .he had to stop numerous times to let it cool down to get it back to his house during the rest drive. What should be check for these issues as it is still overheating I am assuming because the coolant is still disappearing?

When hot shut engine off and disable fan if electric feel radiator for cold spots if any radiator is bad assuming it is full. Then check for a blown head gasket. See link.
https://www.2carpros.com/articles/head-gasket-blown-test

Engine Cooling problem
1998 GMC Envoy 6 cyl Four Wheel Drive Automatic 122. miles

I did what you said and had my system flushed I had heat for 2 weeks and now it works when it want. Do I have a major problem? someone said I may need a new heater core, is that major work or could I do it myself with a little help.

Hi:
Make sure the coolant level is full. Also, is the engine running at a normal operating temp?

The heater core is a job. anyone could do it, but you will need to remove part of the dashboard to get to it. Also, I recommend purchasing a repair manual that will give you step by step instructions and pictures to help identify parts.

Let me know.

Joe

Check your blend door actuator that is located behind your glove box and is a little black box that is screwed up top down on top of your heater box. its hard to get to. Open it up and you might have the plastic gear broken in half.

engine overheating,change fanclutch,still problem persist,relay switch controls fan? if so where's located and how it looks

Check cooling fan relay located on underhood fuse block. If its good then suspect faulty engine coolant temperature (ECT) sensor.