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How-to C6 efan installation

74K views 69 replies 29 participants last post by  BadDog98 
#1 ·
Here is how I installed a C6 Corvette efan on my I6 Trailblazer. I hope these come out large enough to read.

Mark
 

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#5 ·
What happens if...

Hi again,
I searched the market and found a regular fan clutch (not electrical) that fits on the Envoy water pump. Its fan inner diameter is a little smaller than the Envoy's. I can fix that in a workshop making an adapter to use the original Envoy fan on the regular clutch. My questions are as follow:

1- What codes will I have after completely disconnecting the electrical clutch?
2- How can I disable them?
3- If I don't disable them and decided to live with the CE light, will the PCM decide to put the engine on Reduced Engine Power?
If you're interested, the clutch is any Ford model 1995 or 1996. It has the same big nut and distance to the Rad.
I appreciate your quick response.
 
#6 ·
Hi again,
I searched the market and found a regular fan clutch (not electrical) that fits on the Envoy water pump. Its fan inner diameter is a little smaller than the Envoy's. I can fix that in a workshop making an adapter to use the original Envoy fan on the regular clutch. My questions are as follow:

1- What codes will I have after completely disconnecting the electrical clutch?
2- How can I disable them?
3- If I don't disable them and decided to live with the CE light, will the PCM decide to put the engine on Reduced Engine Power?
If you're interested, the clutch is any Ford model 1995 or 1996. It has the same big nut and distance to the Rad.
I appreciate your quick response.
You might, have many codes from the computer as though you took something off that isn't supposed to be there, and if you don't put anything on there you will overheat in a second and just destroy the whole engine. The computer may decide to go into reduced power mode, especially if the fan is not doing its job right, and you set off more codes. You cannot "disable" the codes, as that is part of the computer's job to let you know when something is not working right, so you can turn them off using an OBDII code reader, but they will come back on. Good luck, let us know!
 
#10 ·
Tech 2 will only clear the code(s), not prevent the cel from turning back on. For example, if you unplug a sensor and the ecm sees it, it will turn on the cel and store a fault code. The Tech 2 is able to turn off the light, but when the parameters are met to turn the light back on because the sensor is unpluugged, the cel will come back on. My understanding is, using a program like HPtuners and turning off the code, the ecm ignores the fact the sensor is unplugged, therefore not turning on the cel.

You can go to www.hptuners.com for more information and see if their program will work on your year truck. My suggestion is after confirming hptuners will work on your truck, find someone that already has hptuners AND tuning experience, buy the credits for your vin ($100 or so) and have them turn off the codes. However, if you have the time and desire, buy the hptuners program and learn about how to tune cars. That would a steep learnin curve if you're not experienced in tuning. I guess to get the most bang-for-your-buck from doing your own tuning, you would need access to a dyno. I found it easier to spend the $100 and have my tuner do it for me.

Maybe pcm4less can sell you a tune with the codes already turned off.
 
#11 ·
Great How-To. Thanks. Do you, or anyone know the CFM the C6 fan pushes? I read on a corvette forum it's under or around 2000 cfm. If that's true then why not use a taurus fan or even a lincoln mark viii fan. I've read that tons of people, especially offroaders use the lincoln mark viii efan. They are supposed to push 4500 CFM. I've found some on ebay for about $60, I'm going to try the local junk yard and see if they have any. I'm replacing my radiator so I thought now would be a good time to do a efan conversion as well. Once I get it done I'll post some info. Thanks again for the great how to.
 
#14 ·
RimoniManu.....
Just wanted to know if you found out why no one uses the taurus or lincoln mark fans on the trailblazer .or if you finally put one on your self? My neighbor has a ford junk yard an has some .if you got one to work . would love some info.....thanks
 
#15 ·
Hey lint...
Yes I finally put my lincon mark viii fan in and it's AMAZING. I used the stock fan cowling and trimmed it so I could mount the mark viii on it, that way it will fit the edges of the radiator perfectly and pull air through the entire face of the radiator. I used a fan controller from DC Control the model is 2sp. It's just for the 2 speed ford/lincoln fans and it works great. The controller comes with all necessary parts. You can wire it to the AC compressor to turn on when your AC is on. It can also be wired to stay on for a little while after the engine is shut off. My theory for using a corvette fan is people think that if the efan can keep a high performance engine cool then it will be the best for any engine. Infact some members here have said that's why they go with the corvette fan. But after researching offroad site's, corvette forums, and other high performance sites; they all mention the lincoln mark viii fan as being the best. I can't compare it to a corvette fan because I don't have one, so I can't say if it's better or not, however; This fan pushes huge amounts of air. When I say huge, I mean HUGE. It's hard to describe, but I'm amazed with it and am glad I used a lincoln mark viii fan.
 
#16 ·
One thing you are overlooking by using a fan shroud that covers the complete radiator- all the air must now attempt to go throught the radiator limited by both the fan and the shroud. By using something like the C6 fan, there is a lot of open space to allow the air to pass through the radiator. The purpose of the fan is to keep both the coolant temperature and a/c temps acceptable during idling, stop and go driving, and low speed, high load conditions. After the vehicle is above 40 mph, the fan is not doing much, if anything, to control coolant temps.
FWIW, I proved this on one of our C6 racecars that the 2006 and newer fan cools better than the 2005 fan. The 2005 has a closed shroud whereas the 2006 and up ais opened to allow air to pass through the radiator more easily. The car manufactures must build their vehicles to work in all conditions, whereas we can choose to use whatever components meet our specfifc needs.
 
#17 ·
This is what my fan looks like


So you're saying that because the shroud covers the entire face of the radiator it does not allow air to move "freely".... If that's true then why does the stock shroud cover the entire face of the radiator? I understand at high speeds the fan will restrict the air flow through the radiator if all the air has to go through the fan, however; my tb can't go anywhere near as fast as a C6 racecar. My tb is also more for around town stuff and eventually offroading. That is something I can try though, to see how an "open" shroud compares with my "closed" shroud. As soon I rebuild my tranny I'll work on it. Thanks
 
#18 ·
This is what my fan looks like
So you're saying that because the shroud covers the entire face of the radiator it does not allow air to move "freely".... If that's true then why does the stock shroud cover the entire face of the radiator?
For stop and go traffic and to keep the a/c blowing cool air during those s & g conditions.

If you find that your set up works to your satisfaction, great! I enjoy reading how some one, like you, did it differently. Your train of thought and execution of doing it, along with my way, may have someone else build upon our installs, come up with even a better way. That makes another proven alternative to what I did. I used the C6 fan because of my relationship I have with some GM engineers for techincal help.

I've experienced neither high coolant temps during s & g driving (above 190*f by my Stweart Warner temp gauge) or any rise in a/c duct outlet temps ( the DCControl fan controller turns on the fan any time the a/c compresser is engaged). If I should encounter any adverse s & g coolant temps, the fan controller gives me the option of having the fan on any time my Tb is running.

Keep us updated on what you experience when you get it up and running.
 
#19 ·
Guys,
I'm often on another site, but I thought I would share what I did, as it's sort of in line with yours.

First off, I have a DC Controls unit in the box, and have had it for over three years. It's supposed to go on my Taurus fan and into my '65 GTO, if I ever get around to it.

Not wanting to steal from that car, I really wanted an efan on my TBSS, and I like the variable speed option.

So, after a long while, I got a C6 setup, but I wasn't that impressed with the fan itself.

I am currently running a large, powerful, single 18" fan that is being controlled by the C6 fan module wired into my ECM, and programmed through HPTuners.

I've had in for about five weeks, and it's working great, but I must admit that it just hasn't been very hot here...to say the least. It's the coolest year I can remember, and I have a fantastic memory, and I've been here about as long as my Goat.

Anyways, my plan is to upgrade the wiring in the terminals as I want to go with 12 gauge wiring, and take it from there.
 
#20 ·
My corvette e-fan is on its way to my house. Cost me $205 shipped from eBay. New, OEM too. The Delta Current Control controller is on its way too, $155 shipped. This should be fun!

07TB, how many miles have you put on your truck since you have had it installed? Is it working as well now as the day you put it in? Great thread! :thumbsup:

Any other thoughts?
 
#24 ·
I put mine in around early spring, and probably had a record cool summer, but last week we got hit by 113F temp (all-time record for Los Angeles, for any day, and the thermometer broke at 1PM).

Anyways, I was driving around, some slow traffic as well, and hit as high as 215F on my coolant, and 203F on my trans fluid.

I am running the stock Mk VIII shroud, but I added a C6 PWM module to control it, and a conservative fan speed setup.

If you keep the fan maybe around 90% max, it will still pull a ton of air, but not tax the electrical system too badly.

The thing you don't want to do with these Mk VIII fans is have them turn on full speed from a stop, as I have tested it, and it will spike at 87A for a moment, before settling in at around 38A (these amperages were tested at about 12.4VDC, they may in fact be less at 14+ VDC, but I haven't tested it at those voltages at this time).
 
#45 ·
If you keep the fan maybe around 90% max, it will still pull a ton of air, but not tax the electrical system too badly.

The thing you don't want to do with these Mk VIII fans is have them turn on full speed from a stop, as I have tested it, and it will spike at 87A for a moment, before settling in at around 38A (these amperages were tested at about 12.4VDC, they may in fact be less at 14+ VDC, but I haven't tested it at those voltages at this time).
In a DC system the current goes up as the voltage increases. The Mark VIII fan will draw over 100amps on startup with higher running voltages, 13-14v.

In an AC system the voltage will drop at voltage increases.
 
#26 ·
Thanks for the info.That sounds pretty good.Have you noticed any increase in mpgs? Where did you get the c6 pwm module?I really appreciate the info.What year Lincoln is te fan from?
I honestly feel the mileage has increased between 1 and 1.5 mpg, keep in mind that I drive the TBSS w/ 4.10 gears.

I will say there is more throttle response, though I haven't raced or timed it before or after.

I bought a couple of C6 fan setups, sold one fan only already, and should sell the other fan w/ module, but haven't gotten around to it yet.

I also have another Mk VIII fan and box that I may fab up and sell as a kit.

Not sure what year the fan is, perhaps around 94-96 or so. The one I used is a 2 speed, and I wired it on the high speed side, but even the low speed side puts out a lot of air. But, with the PWM, why wire the low speed, at least that was my thought process.
 
#29 ·
Awesome how-to article. I'm def planning on efans here in the next month or so. Though, I did notice on your temp probe instructions. You said to place it near the outlet hose, which is correct, but you said it was the lower hose. The outlet hose from the motor is the upper hose which is the outlet for the thermostat. :thumbsup:
 
#35 ·
Lint, I think he was talking to me going from this post:



Even if he wasn't talking to me, his information is wrong. Maybe he'll believe the GM shop manual, or when he removes the upper hose from the engine and doesn't find a thermostat. Next he'll tell me LS engines have the thermostat in the upper hose also.
 
#31 ·
Well, first off I was trying to kindly show you that you were mistaken. If you want to make a post and have it be wrong, that's fine. Except now, ppl are takin this info and doing it themselves. SO now not only are you jacked up, your screw'n your buddies as well. :nono:

Second, there are other how-to articles that describe replacing the I6 thermostat, they all remove the upper hose from the side of the motor to replace it. Plus any motor I've ever worked on has the thermostat on the top of the engine or on the upper side. Why, heat rises, hence the outlet for the cooling system is always towards the top of the motor. Even though it may enter the top or side of the radiator it's always towards the top. The pump always pulls coolant thru the lower portion of the rad. Why would you pull hot coolant off the top of the rad? this makes no sense.

I'm no good with electrical stuff so I always ask questions especially if I'm not sure. This is a forum, we are all here to help each other with our vehicles and to sort out problems. If you would'a posted info proving your point fine. But to just say it's right cause you wanna be right and stay ignorant is no good. This is basic cooling system knowledge, if it was science theory and a debate then fine, everyone has an opinion. THis is mechanical, the system is what it is, It doesn't change from one 360 platform to another. :coffee
 
#33 · (Edited)
Well, first off I was trying to kindly show you that you were mistaken. If you want to make a post and have it be wrong, that's fine. Except now, ppl are takin this info and doing it themselves. SO now not only are you jacked up, your screw'n your buddies as well. :nono:
Wow, aren't you brutal for someone who does not know what he is talking about. Maybe you should read the GM shop manual procedure. In case you don't have it readily available, I post it here.

Engine Coolant Thermostat Replacement (4.2L Engine)
Tools Required
J 38185 Hose Clamp Pliers

Removal Procedure
Remove the necessary coolant from the radiator. Refer to Cooling System Draining and Filling .
Remove the generator. Refer to Generator Replacement .
Loosen the outlet hose clamp at the thermostat housing (#1). Remove the outlet hose from the thermostat housing.
Remove the thermostat housing bolts.
Remove the thermostat housing from the engine block.
Clean all of the surfaces of the thermostat housing.
Clean the sealing surface of the engine block.


Installation Procedure
Install the thermostat housing to the engine block.
Notice: Refer to Fastener Notice in the Preface section.
Install the thermostat housing bolts.
Tighten
Tighten the bolts to 10 N·m (89 lb in).
Lubricate the inner diameter of the radiator hose with engine coolant.
Install the outlet hose to the thermostat housing (1). Secure the hose with the clamp.
Install the generator. Refer to Generator Replacement .
Fill the cooling system with specified coolant and concentration. Refer to Cooling System Draining and Filling .
Inspect all sealing surfaces for leaks after starting the engine.
 

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#36 · (Edited)
One week after getting my i6 the stat went. got the Haynes Manual out, and it starts saying to remove the top hose, it even has it wrong ,but if you read on down in another part it says something about the stat is in the bottom . Thats how I found this site. :tiphat who would have thunk it...
 
#38 · (Edited)
Coolant flow in these engines is from bottom to top. The thermostat is located in the coolant inlet to the engine not the outlet like, for example, a small block chevy. LS thermostats are in the housing bolted to the water pump, but the coolant circulates through the heads first then the block and back into the water pump, out through the upper rad hose and then into the top of the radiator. The reason why the people on ls1tech are having air pockets, is they are not filling the coolaning systems properly.

As far as to where to locate the probe, the instructions from DCControls- the manufacturer of the fan controller I used- said to mount it near the bottom of a down flow radiator. Flex-a-lite's probe and controller may be set to mount the probe in, or near, the upper hose. My suggestion is to follow the instructions as to location of the probed based on whose controller you end up using.

no harm. no foul. We are all here to learn something. And I do learn something new about these trucks everyday!
 
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