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Hello


Actually this is my first post here and I'm facing a temperature problem with my GMC envoy 2004 4.2 L 4X4.
I'm living in Dubai and the weather here is very hot in summer, since around 6 month the temperature of the engine starts going up (more that 240) when I'm driving inside the city and when I'm using the air condition.
The strange thing that when I'm driving on high way (no traffic Jam) the temperature is normal (210).

I don't know what is the problem but I went to the garage and they checked the water pump and the radiator and they said that they are fine, I'm stick since no body knows what is the problem and they can not fix it and I'm using the car to drop my kids to school every day and I'm afraid that the car will break down.

Can any one help me to identify the problem??

Thanks
 

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2009 chevy
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6,431 Posts
Hi, welcome to the site. :thumbsup:

I'll bet it's hot, around 44 c maybe.

You could have a thermostat problem, or, you might have restricted air flow through the radiator; but if it works ok while driving on highways, those may not be the problem.

Also possible, a program update, for the PCM, is required.

The engine cooling fan engagement is controlled by the PCM and, GM has changed those program parameters to engage the fan earlier.
 

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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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3,700 Posts
When the engine is that hot, in the city, do you hear a "roar" from the fan, when you are accelerating?

I suspect your fan clutch is going out, because if the temperature is good on the highway, the only difference is airflow...

Mike
 

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2004 gmc
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And if the vehicle is from 2004, and the fan clutch was never changed, it's in the time period when they were known to be unreliable. The redesign happened in 2005. You might try carefully (!) to stop it with a rag from rotating at idle. If you can stop it, it's bad, or less likely, there's an electrical control problem.
 

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2003 gmc envoy_slt
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361 Posts
And if the vehicle is from 2004, and the fan clutch was never changed, it's in the time period when they were known to be unreliable. The redesign happened in 2005. You might try carefully (!) to stop it with a rag from rotating at idle. If you can stop it, it's bad, or less likely, there's an electrical control problem.
Just to clarify. If the temperature is below 210* at idle and I can stop it is it possibly bad? I know that when you first start it you shouldn't be able to stop it for the first 30 seconds or so (don't recall the exact time), then you can stop it.
 

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2004 gmc
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You got me curious if I've been giving out bad advice, and I might be. I just went to my own truck, and on a cold start, I could stop the fan with a rag. :eek: If there's PCM programming to force the fan to go on to improve AC performance even at idle, I wasn't seeing it happen, and I thought I had that update from 2005. That may be an issue with my tune overwriting the factory calibration, but I loaned out my OBDII cable so I can't reflash it back to the original, or look at the commanded versus actual fan RPM.

So I have to say the only true driveway test of a bad fan is if you can stop it with a rag when you're already at or above 210.
 

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You got me curious if I've been giving out bad advice, and I might be. I just went to my own truck, and on a cold start, I could stop the fan with a rag. :eek: If there's PCM programming to force the fan to go on to improve AC performance even at idle, I wasn't seeing it happen, and I thought I had that update from 2005. That may be an issue with my tune overwriting the factory calibration, but I loaned out my OBDII cable so I can't reflash it back to the original, or look at the commanded versus actual fan RPM.

So I have to say the only true driveway test of a bad fan is if you can stop it with a rag when you're already at or above 210.
I just tried my own truck and at cold idle i could easily stop the fan with the AC off or on. I couldn't test 210 or above because before it got hot it started pouring rain so temp never got above 180* and at that I could still sop the fan. I also have a tune albeit from another vendor.
 

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2002 gmc envoy_slt
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And 210 or below at idle doesn't really mean a whole lot, the I6 takes forever and a day to warm enough to engage my e-fans at idle....unless I turn the a/c on and then they both turn on. (The heat output at idle can almost be handled w/o the fans running).

If its really not there, keep in mind that running the a/c basically places a 160 degree or so heater in front of the radiator, making the air temps pretty high by the time they pass through the radiator.
 

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2005 chevy trailblazer_ls
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916 Posts
Hello


Actually this is my first post here and I'm facing a temperature problem with my GMC envoy 2004 4.2 L 4X4.
I'm living in Dubai and the weather here is very hot in summer, since around 6 month the temperature of the engine starts going up (more that 240) when I'm driving inside the city and when I'm using the air condition.
The strange thing that when I'm driving on high way (no traffic Jam) the temperature is normal (210).

I don't know what is the problem but I went to the garage and they checked the water pump and the radiator and they said that they are fine, I'm stick since no body knows what is the problem and they can not fix it and I'm using the car to drop my kids to school every day and I'm afraid that the car will break down.

Can any one help me to identify the problem??

Thanks
Welcome! :tiphat

There's a TSB about overheating in high ambient air temperature. Search the forums and you will find it. I have also experienced overheating problems in the past few months and discovered that my problem was a blown head gasket.

Where are you located at in Dubai? I'm trying to get more GMT360 owners in the GCC, and UAE in particular, introduced to TrailVoy.com, but not having a lot of success at the moment. Make a few more posts (I think 20 are required), add at least three pictures to your Gallery, then apply for membership in the International Chapter.

There are a lot of great folks here with a wealth of knowledge and experience just waiting to share it. :grouphug: We all look forward to your contributions as well.

It’s easy to find answers to your questions. The Search Engine is accessible from several locations. Just look for the word “Search” and click on it. A box will open where you will enter your search criteria. “Search” is you friend. Know it. Use it. Love it! :thumbsup:

Have you checked out the Site Rules yet? The site rules can be found under the Resources drop-down menu at the top of any TrailVoy page. A link follows this paragraph. Site Rules provide guidelines for being a responsible participant in the TrailVoy community. :yes: I'm sure you will enjoy this site and it will serve you and your TV for a long time to come. :)
http://forums.trailvoy.com/view.php?pg=rules
 
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