Cooling - Towing and AC On - 2004 Trailblazer LT 4x4 I6

Discussion in 'Engine & Drivetrain' started by webdawg, Jul 27, 2016.

  1. webdawg

    webdawg Well-Known Member

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    So I was towing recently and when I turn my AC on, just with the trailer and 5 boxes in it, the temp gauge would raise past the point it usually sits at.

    I needed to move so I loaded the trailer up and drove 12+ hours in 100 degree+ weather with the windows down and the A/C off. If I would have to push the engine to 4k the temp would go up. If I would turn the ac on cruising at 70 MPH the temp would go up.

    Do I have a bad water pump here? Fan clutch? Both?

    I was looking at: http://forums.trailvoy.com/showthread.php?t=71429 and it seems strait forward. I also think that my AC system is over/under filled and needs serviced.
     
  2. littleblazer

    littleblazer Gold Supporter

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    Well... the truck can run around 220 while towing with the stock setup. It's marginal as it is and any extra weight causes it to rise rather quickly. The ecm doesn't really command higher cooling until it gets in the 220s iirc. Once you get closer to 260 that's when things start to go weird.

    A bad fan clutch will run hot at idle and cool when you're moving. And ac performance will suffer at a stop.
     
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  3. webdawg

    webdawg Well-Known Member

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    I have the AC Performance suffering at stop right now, in fact it hardly works without me moving the vehicle.
     
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  4. nathaniel

    nathaniel Member

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    My temp doesn't seem to change much when towing around 2000 lbs with the AC on, even when going up a grade. Of course, it's rarely above 85 out here in Western Oregon, so don't know how much of a factor that is. My gut feeling is that you have a cooling system component issue...
     
  5. littleblazer

    littleblazer Gold Supporter

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    With my thermal clutch pulling around 4k it rarely goes above 206
     
  6. Mooseman

    Mooseman Moderator

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    I would definitely suspect a bad fan clutch. You should check the water pump at the same time for bad bearings.
     
  7. webdawg

    webdawg Well-Known Member

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    Any recommendations on a replacement? I will never purchase DORMAN anything again so options look to be:

    $128.79 - GPD 2911336
    $150.79 - HELLA 376734021
    $227.79 - ACDELCO 1540133

    Unless someone chimes in saying that the DORMAN is working great for them over the last few years, it looks like those are my options. The ACDELCO is steep heh.
     
  8. djthumper

    djthumper Administrator

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    I don't know what kind of temps you are getting in Everywhere... In Vegas I don't have those problems even when it is 118 out and towing around 2500+LBS. I replaced my fan clutch with a Dorman over 5 years ago now and have not had an issue. I have replaced my water pump 3 times and the last time was with an AC Delco. I would would actually check the system to see what it is doing. When was the last time you changed the coolant? Have you checked the AC pressure?
     
  9. webdawg

    webdawg Well-Known Member

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    Thanks for the most excellent response and information. I have collected the information I need to move forward I think.

    I have a lot of things to check.
     
  10. Mooseman

    Mooseman Moderator

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    BUT, DJ's luck with the Dorman is out of the ordinary. Hayden has been the preferred brand here. But, if you want to truly eliminate the troublesome electro-viscous clutch, get a tune to turn off the fan codes and get a thermal clutch from a 2008 TB. It's less expensive and with the cost of the tune ($99), will also benefit from other things like better shifting and possibly better MPG.
     
  11. nathaniel

    nathaniel Member

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    That glass boat your towing is definitely heavier than my aluminum! Lately I've been considering switching to a glass hull to minimize pounding in heavy waves on the Columbia River\ocean.
     
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  12. littleblazer

    littleblazer Gold Supporter

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    Driving like it's not back there doesn't help either but it tows nicely with the tune and helper bags. I have tried to launch it a couple of times off waves and you just end up plowing them. 4 winns really didn't make crap back then.

    Back on topic I would test the fan clutch and go from there. My truck has always climbed as did the voy but once it hit the 220s you heard the fan start pulling more and once you moved breifly it went down to 213 which is probably fine.
     
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  13. webdawg

    webdawg Well-Known Member

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    I see a Hayden fan clutch on RockAuto but:

    HAYDEN 3200 Electronic Info
    [​IMG] [​IMG] [​IMG] Reverse Rotation Severe Duty Thermal Fan Clutch

    What does the Reverse Rotation Mean? Is this the right one for my vehicle?

    Also, I see two waterpumps. Professional vs OEM...what is the difference:

    ACDELCO 252822 {#89036357} Professional|; Does Not Include Mount Bolts; Includes Gasket Info [​IMG]

    35.79


    ACDELCO 251731 {#12620226} GM Original Equipment Includes Gasket; Includes Gasket Info
    [​IMG] [​IMG] [​IMG]

    82.79

    I would want to get the cheaper one if it was the same.

    I was also looking at this:

    http://www.pcmofnc.com/product/pcm-of-nc-fan-clutch-wrench-3/

    vs this:

    http://shop.advanceautoparts.com/p/autocraft-fan-clutch-wrench-set-2-piece-ac660/10051070-P

    Any differences?
     
    Last edited: Jul 29, 2016
  14. littleblazer

    littleblazer Gold Supporter

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    Professional and oem should be the same.

    @MAY03LT has a nice video on removing the fan nut and he shows a pretty good tool that could be had on ebay.
     
  15. webdawg

    webdawg Well-Known Member

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    That one? Watching it now. This video is great.
     
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  16. Mooseman

    Mooseman Moderator

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    I just use a large adjustable crescent wrench. I have seen a pipe wrench used before. If it's reallly stuck, the chain method is really good.
     
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  17. nathaniel

    nathaniel Member

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    I use a 1-7\16" wrench for the nut and check out the fan clutch holding tool from advanced auto. Mine comes off easily though. Also, if you unbolt your fan clutch from the fan you can maneuver the whole assembly out easily around the radiator neck. Just make sure to put a cardboard piece between your radiator and clutch for protection.

    On another note, I've been driving in the eastern Washington desert heat this weekend and the trailblazer has definitely been running hotter. It was around 106 degrees and the coolant temp was reading around 220 while driving in town, and 210-12 freeway. I just replaced the water pump, coolant temp sensor, fan clutch, and thermostat recently, and the radiator was replaced last year so I'm pretty sure everything's solid.
     
    Last edited: Jul 30, 2016
  18. webdawg

    webdawg Well-Known Member

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    I tested the fan clutch a few days ago. How much tugging should I expect? I was not hard to keep it stopped, it was hard to stop once it got moving.

    I stopped the fan, and watched it start again.
     
  19. DocBrown

    DocBrown Well-Known Member

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    One question I have to ask, do you have any kind of custom grill insert or shell replacement? These can impede air flow. In normal driving it's not a problem, but when towing you won't get enough air flow and both engine and trans temps will go up. AC will not perform well either because the condenser needs good air flow too.

    And I know this from personal experience. I have a custom grill insert on my Sierra. Last Sept we towed our travel trailer to Gatlinberg. Going through Indy it was nearly 90 and my trans temps were pushing 120, engine was 220+. Took the insert out, trans dropped to 170, engine back to just under the 210 mark.
     
  20. Mooseman

    Mooseman Moderator

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    It should have an actual feeling of it "wanting" to start rotating as opposed to just freewheeling with practically no resistance. It will start rotating just from friction in the bearings but basically still just freewheeling and easy to stop again, like in the video, if it's dead.

    Another way that someone else has suggested is to apply 12v+ to the white wire on the fan. This would basically be 100% fan duty and should lock it up, making it sound like a garbage truck fan when you rev it. It can take about minute for it to happen.
     
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  21. C-ya

    C-ya Well-Known Member

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    Reverse rotation is a way to differentiate between the old V-belt water pumps that rotated the other direction. Serpentine belts systems run the water pump in the "reverse" direction. When I put a small block Chevy in my Isuzu Hombre, I used a block from a Chevy van that was V-belt. I had to get all new brackets and accessories for the serpentine setup in order to use it, which meant a water pump from a vehicle that was equipped with a serp belt. It was fun buying parts for it - just had to keep the "donor" vehicles straight in my head!
     
  22. webdawg

    webdawg Well-Known Member

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