SOLVED! Efan Replacement for Stock 2006 Envoy Denali Cooling

Jkb242

Original poster
Member
May 19, 2019
239
CLT
The primary reason is to get rid of the problematic clutch and the huge fan shroud complicating belt changes especially the AC belt. Replaced the clutch a few times and obviously “good” replacement clutches is hit or miss at best.

The input I am seeking is what efan solution is as good as the stock setup FOR AVERAGE driving only, no off road or performance mod. Simply want to free up the space used by the stock fan/shroud with the electromechanical clutch failure prone stock equipment.

Radiator is stock, no desire to mod up. I’ve read the Efan Debate section here which I did not find particularly helpful in attempting to realize the practicality of my primary objective. I do not want invest hundreds as that isn’t practical but I have noticed less expensive solutions but I do not want to trade size reduction for another issue either that could result in an increase in NORMAL operating temps above 230F. Currently, fully operating temps are right at 200F.

Thanks so much in advance to this great forum. I’ve come here often over the years for the outstanding support I always find. Thanks
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
I had the same desire and goal a few years ago when my EV clutch failed.

I was able to source a PCM of NC shroud from their I6 efan kit, bought a high output 16" Spal fan, variable speed fan controller, and assorted wiring. I had that setup on my truck for not even a full weekend. It was May, and in Florida. At best, the setup only maintained temp at idle, or slowed heating with just surface street/traffic light driving for a half an hour. It never brought temps down, even sitting at idle in my garage with the fan commanded at high speed (due to a temperature override switch I installed)

It would have cost me a lot more money to get a custom shroud to try a pair of 10" or 12" fans, but my mind was already made up. I ended up returning everything I could, bought an 08+ thermal fan clutch, and had the DTC code tuned out. Have been happy ever since. My normal operating temps are also right around 195-200, maybe get up around 205-210 following extensive highway driving and the AC running in the summers. :twocents:
 
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Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
Same here. They're not worth the trouble. You're better off getting a thermal fan clutch from an 08-09 and getting your PCM tuned to turn off the codes, and getting a few improvements at the same time. And A/C performance at idle also suffers no matter which fans you use.
 
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TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,047
Brighton, CO
I have to agree with @Blckshdw , E-Fans are not worth the hassle, and actually make things worse. AC function will suffer, tranny/engine temps will also suffer.

My EV on my Envoy has been apsolutely problem free for 100k miles, original lasted 112k miles.
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
Thanks to everyone for the replies and the valuable feedback on the E fan mods! I’m fortunate enough to live close to PCM of NC and have been there a few times for different reasons. Great folks indeed. Very curious about the 09 clutch next time I need one, would using that require the same year fan shroud? Are there any other items requiring attention other than programming out the DTC code? What changed in the clutch design to make that year better, longer lasting? Perhaps I have been unlucky with replacement fans (never Dorman) AC or others as recommended here on last service required.

Does anyone know a way to change the AC belt without removing the fan and shroud? I know the fan has to be disconnected from water pump pulley/belt connection to install the new belt but it looks like a real pain, if even possible? Any recommendations? Removing the shroud means loosing coolant top hose, but also thinking of a simple way to quickly capture it in case I have to remove the shroud.

Much thanks!!
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
When I swapped to the thermal clutch, nothing else was required, hardware wise. It was a direct swap, I put some electrical tape over the old EV clutch harness to keep it clean and dry. Then tucked it out of the way.
 
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TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,047
Brighton, CO
@Mooseman I thought had a way to trim the fan shroud so you dont have to remove it, and can just remove the fan, while leaving the clutch?? He could elaborate more.
 
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Jkb242

Original poster
Member
May 19, 2019
239
CLT
When I swapped to the thermal clutch, nothing else was required, hardware wise. It was a direct swap, I put some electrical tape over the old EV clutch harness to keep it clean and dry. Then tucked it out of the way.
Thanks, great to know! By the way, on the 5.3L engine isn’t the crank rotation clockwise facing the front of the engine? That would mean the fan nut has a left hand thread since loosening it would be clockwise as well? Thanks
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
Fan nuts are the same. Both use the same clutch. No mods or anything else. It's a direct bolt in. At most, you just need to have the fan codes turned off. However, you can also get other things tuned, like transmission shifts, to just improve it. Costs the same.

The mod I did was to cut off the top of the fan shroud.

PXL_20220815_211826795_resized2821135196413711162.jpg

Others have been able to remove the clutch without removing the shroud by removing the four bolts that hold the fan to the clutch and then unscrew it from the water pump shaft, and then carefully move the clutch towards the radiator and wiggle it out.

And on my Saab with the 5.3, I was able to remove the fan with the clutch out the bottom. I tried to do that with my 4.2 and it wouldn't go, even with that weird unknown use bracket removed.

I prefer the cut shroud method.
 
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Jkb242

Original poster
Member
May 19, 2019
239
CLT
Cool Mooseman, that looks like a possible fix to remove clutch and fan as well without removing the entire shroud.

I was having more difficulty than ever loosening the clutch nut from the water pump then discovered the .25 dia holes in the pulley to be used with the pulley holding tool (which iI don’t have) to securely hold the pulley from turning. After a hour of screwing around I felt like a “NUT” after discovering them. I guess I forgot that since I rented the removal tool from Autozone when I changed clutch a couple years ago and didn’t require it when re-installing. Perhaps a “senior moment” @76 I don’t have many but it’s never convenient. :smile:.
Thanks indeed!!
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
I use the air hammer on the hex towards the side to unscrew. Works like a charm every time. Another way is to use a big wrench and whack it with a BFH towards the direction to unscrew. That method doesn't always work, especially if it's never been removed.
 
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Jkb242

Original poster
Member
May 19, 2019
239
CLT
I ended up using the Autozone tool rental that was suppose to hold the pulley while I turned the fan nut. See pictures of the tool and noticed it had no pins to fit the pulley holes intended for holding it. I used 2 6mm 2” screws taped to the tool to keep the screws in place which worked perfectly after a fit of fiddling.

Now with the fan separated from the water by 1/4” serpentine belt removed I’m attempting my entire reason for all this: “Replace the ac belt that is cracked”, and yet it’s another nightmare. Even with the tensioner fully released, that belt is not wanting to come off, it’s seems too tight to reach over the AC pulley while the other end is still on the crank pulley. There must be a particular procedure. Naturally, it would be nice to rotate the crank pulley to walk it off but is that actually possible using a breaker bar or even advisable? Suggestions?
 

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TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,047
Brighton, CO
If you got a new belt, and are sure of yourself putting the new one on, just use a pair of wire cutters, and cut the old one off.
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
Thanks again for all the comments. I guess I over-complicated this attempt to replace the AC belt. The main serpentine belt is fine so removing the fan nut was never required. At any rate, since this is the first time I have attempted replacing the AC belt, I did not expect the effort to be much different from that required to replace the main belt. Anyone have any suggestions doing this while lying on the ground since it isn’t possible to use your body weight to rotate the crank.
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
You shouldn't have to remove the fan to replace the main serpentine belt. I do know you have to remove that belt to replace the A/C belt. Maybe removing the nearby bracket/shield can give you some extra room. It's just 2 13mm bolts.
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
You shouldn't have to remove the fan to replace the main serpentine belt. I do know you have to remove that belt to replace the A/C belt. Maybe removing the nearby bracket/shield can give you some extra room. It's just 2 13mm bolts.
Correct indeed, I wasted quite a bit of timing screwing around spending time doing things that weren’t necessary. It’s all done now including the AC belt.

I don’t believe the temp gauge is working. After about 10 minutes idling, temp gauge barely reads. Have a check gauges trouble light on dash, which I have never see before. Haven’t read any codes with the code reader but no MIL so likely no codes are set so far.
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,047
Brighton, CO
You may have mistakenly unplugged the temp sending unit. Its the sensor on the front of the head, drivers side, just above and in front of the #1 spark plug. This will cause both of the issues you have.
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
Thanks I’ll check that tomorrow AM! 👌
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
Connection to coolant sensor is good in terms of the connector seating. Can anyone tell me with ignition switch on, car not running, should 12v be present across the connection to the sensor or at least to the yellow wire to ground? Additionally, what is the nominal resistance of the sensor when coolant temp is at 100C? I would like to start with these reading in trouble shooting the “check gauges” light and the associated constant low temp gauge reading.

Thanks
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
I discovered the the coolant temp circuit is on the 5vdc reference from the schematics posted so graciously by Mooseman. Thanks again for that wonderful material. I have 5vdc on the yellow lead per the schematic so possibly the sensor is defective. It’s only been a couple years ago since II replaced it.
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
Please marked this thread solved, the “check gauges” light was the results of an intermittent connection in the connector to the sensor even though connector was fully seated and locked by the retaining notch on the sensor and the clip on the connector.

Thanks to all….
 
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Jkb242

Original poster
Member
May 19, 2019
239
CLT
Same here. They're not worth the trouble. You're better off getting a thermal fan clutch from an 08-09 and getting your PCM tuned to turn off the codes, and getting a few improvements at the same time. And A/C performance at idle also suffers no matter which fans you use.
Can you tell me which manufacture did you use for the thermal fan clutch to use as a replacement for the stock electronic clutch. Thinking of this mod since you mentioned it when I need to replace my stock clutch.

Thanks
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
For the thermal, Hayden used to be the go-to however, it has fallen out of favour. It has a tendency of being loud when first started. ACDelco operates as it should. If you don't mind the fan noise when first started, the Hayden will work fine.
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
Thanks very much. The initial fan noise is ok but with the stock one, the noise continues until 100c or slightly above then becomes quiet. I would like to shortened the noise before the 100c time with a thermal clutch. You think this is possible or more likely a hit or miss.

Thanks again!!
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
Yeah, usually after a minute or two of driving, it quiets down. Hate driving around sounding like a dump truck :uhno:
 

Jkb242

Original poster
Member
May 19, 2019
239
CLT
True, but other than being just a temporary annoyance, playing it safe, given the rather minimal gains over a properly operating stock fan/clutch, maybe best not to fix what isn’t broken. Thanks for your abundance of information and wealth of experience!
 
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