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2004 chevy trailblazer_lt
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Discussion Starter #1 (Edited)
About a week ago I started my car (2004 TB LT 4.2 6L) and the fan was making a roaring noise - or I believe it was the fan. I turned off the AC and restarted the engine and it seemed to have gone away.

The following might be relevant to that experience but I'm unsure;

Yesterday I went out for lunch and when I turned the car on I had heard what seemed to be a belt squeal noise - which I haven't heard from this car yet. Now there's a coolant leak near the water pump. After looking up replacing the pump I've learnt that a bad fan clutch and bad pump could go hand in hand. So I'm wondering if I should replace both of them.

Every now and then a code for the fan speed and even a code for coolant temperature would pop up. Right now there's only one code - being for the crankshaft. That one comes and goes - has since I bought the car two years ago.

I'm hoping for some input from someone who has dealt with this before.
 

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2004 chevy trailblazer_lt
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Discussion Starter #2
Random question... could any of this be relevant to my car hitting high RPMs to get out of 1st gear? That's been a concern since I bought the thing but doesn't seem to be an issue if I've been driving for a while.
 

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2004 gmc envoy_slt
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A bad fan clutch can cause a roar sound at start-up and it can cause fault code for a speed problem. The fan clutch should not cause water pump to fail unless it is way out of balance. I think you have a bad clutch and water pump. Good news is that replacing only one is just as replacing both.
As far as engine revving to higher RPMs to go from 1st to 2nd, it is possible the coolant temperature is too low or not coming up to operating temperature fast enough.
 

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2004 chevy trailblazer_lt
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Discussion Starter #4 (Edited)
Thanks for your reply! It looks like someone had already done work to pull the fan assembly out. But I have no idea when or why. It’s got 160k miles on it so maybe I should just do both. Which turns an $80 job to a $300 job :cry:
 

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2004 chevy trailblazer_ls_ext
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Thanks for your reply! It looks like someone had already done work to pull the fan assembly out. But I have no idea when or why. It’s got 160k miles on it so maybe I should just do both. Which turns an $80 job to a $300 job :cry:
But then you only have to do it once. If it were me, I would use genuine AC/Delco parts, or a good solid reputable brand of aftermarket parts. Cheap eBay specials from China pretty much guarantee you'll be doing this again within a year.
 

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2004 chevy trailblazer_lt
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Discussion Starter #6 (Edited)
Already plan on AC Delco. $350 for the two and shipping.

So that noise the other day was from the clutch being stuck open?

I had just checked out the fan while in idle. Coolant was spritzing out of the pump towards my face. It steadily drips out even after the engine is off for hours.

This is definitely my learning car lol
 

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2004 chevy trailblazer_ls_ext
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I ordered one of these to have on hand for the day when I have to do this job:

Note: This does not slip over the head the water pump pulley bolts. You have to remove two bolts and bolt this on. You still need a wrench for the fan clutch nut, but this gives leverage to hold the pulley in place while you loosen the fan clutch nut.
 

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2004 chevy trailblazer_lt
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Discussion Starter #9
Thank you for your replies!

Normally the the fan runs loud for a minute or so when I start the car cold but the experience from my first post was a far cry from normal behavior. It also only happened that one time.

Thank you for the links, guys. Very useful. Hopefully I'll have everything before the end of the week.
 

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2004 chevy trailblazer_lt
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Discussion Starter #10 (Edited)
Does anyone know the wrench size for the fan clutch bolt?
EDIT: likely 36mm (just shy of 1 1/2")
Everything has already been answered on trailvoy lol

And that tool will definitely help. Only $10 from RA. Whatever makes my life easier.
 

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Discussion Starter #13
What's the average life expectancy for water pumps? Judging by the tool marks I think the pump could have been replaced at some point but not the fan clutch.

It's not changing my choice of replacing both. I'm just wondering why the previous owner (a sketchy garage mechanic) went in there. Every time I work on this thing I'm fixing what the "mechanic" half-assed.
 

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The life expectancy really depends on the brand of pump and how well the assembler did their job. An AC-Delco pump could go for 15 years and 150,000 miles and one from Billy Bob's Bargain Barn might last a year, if you're lucky. That's why in one of my earlier posts I recommended AC-Delco parts, which you said you're going with. (y) (y)
I know what you mean about people doing a 50%-donkeyed (trying to be polite here) job on things. The house we bought is filled with things I just look at and wonder "What were they thinking when they did this?! :unsure:
 

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Discussion Starter #16 (Edited)
Thanks, guys.

Is that an aftermarket blade in that photo?
Did you do the power steering lines and give up on getting that bottom clip back on? It was a huge PITA when I did mine but a buddy with smaller hands managed to get to it. Along with stacking like 3 wrench extensions...

Just got my 36mm wrench/back-up home defense tool :LOL:
Fan clutch wrench (actually the pulley holder) and the two parts should be in tomorrow. I've mentally rehearsed the job so much I'm hoping to get it done in under 2 hour Thursday evening.

I'm an optimistic guy lol. I'll report back on how it goes.

Folks are asking me why I'm not replacing the thermostat. I suppose that's something I'll keep in mind along with the belt. Though I feel that's a job for a different situation.
 

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About a week ago I started my car (2004 TB LT 4.2 6L) and the fan was making a roaring noise - or I believe it was the fan. I turned off the AC and restarted the engine and it seemed to have gone away.

The following might be relevant to that experience but I'm unsure;

Yesterday I went out for lunch and when I turned the car on I had heard what seemed to be a belt squeal noise - which I haven't heard from this car yet. Now there's a coolant leak near the water pump. After looking up replacing the pump I've learnt that a bad fan clutch and bad pump could go hand in hand. So I'm wondering if I should replace both of them.

Every now and then a code for the fan speed and even a code for coolant temperature would pop up. Right now there's only one code - being for the crankshaft. That one comes and goes - has since I bought the car two years ago.

I'm hoping for some input from someone who has dealt with this before.
^ yes, unfortunately due to the extra weight of the electrohydraulic fan, the water pump is more stressed. There is a 'weep hole' at the bottom of water pump, before it fails completely it will seep coolant out of there. The repair involves taking out the fan to replace the water pump. The fan itself isn't necessarily bad. When the fan 'locks up' (blades always spinning) thats the indication the fan assembly is bad.
 

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2005 buick rainier
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About a week ago I started my car (2004 TB LT 4.2 6L) and the fan was making a roaring noise - or I believe it was the fan. I turned off the AC and restarted the engine and it seemed to have gone away.

The following might be relevant to that experience but I'm unsure;

Yesterday I went out for lunch and when I turned the car on I had heard what seemed to be a belt squeal noise - which I haven't heard from this car yet. Now there's a coolant leak near the water pump. After looking up replacing the pump I've learnt that a bad fan clutch and bad pump could go hand in hand. So I'm wondering if I should replace both of them.

Every now and then a code for the fan speed and even a code for coolant temperature would pop up. Right now there's only one code - being for the crankshaft. That one comes and goes - has since I bought the car two years ago.

I'm hoping for some input from someone who has dealt with this before.
Replace both of of them. I did the fan clutch and then had to do the pump later on.

About a week ago I started my car (2004 TB LT 4.2 6L) and the fan was making a roaring noise - or I believe it was the fan. I turned off the AC and restarted the engine and it seemed to have gone away.

The following might be relevant to that experience but I'm unsure;

Yesterday I went out for lunch and when I turned the car on I had heard what seemed to be a belt squeal noise - which I haven't heard from this car yet. Now there's a coolant leak near the water pump. After looking up replacing the pump I've learnt that a bad fan clutch and bad pump could go hand in hand. So I'm wondering if I should replace both of them.

Every now and then a code for the fan speed and even a code for coolant temperature would pop up. Right now there's only one code - being for the crankshaft. That one comes and goes - has since I bought the car two years ago.

I'm hoping for some input from someone who has dealt with this before.
 

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I recently installed the "genuine" AC Delco water pump I received from Rock Auto, so far so good. The box and a sticker said AC Delco, but on the back side of the pump a small white sticker said "Made in China"...
 
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