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Discussion Starter · #1 ·
good morning All
Having an issue with over heating. It started when i tried to convert to electric fan. I'll post some pictures later today but in the meantime its overheating. Im in the process of flushing the system so there's no T stat. at the start of the conversion i installed new waterpump, new t stat, coolant champion 3 row aluminum radiator, Derale adjustable fan controller and all new sensors. Wiring and Gauge confirmed operational besides burping it what else could it be.















94 yj 4.0L pretty much stock
 

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1995 YJ Wrangler SE
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Derale and Hayden have crap and i mean potentially catastrophically crap controllers.

That's a start. Before the anti-electric fan crowd appears here with their pitchforks... do yourself a favour and get a Flex-a-lite adjustable fan controller. The rad probe version works fine, but ideally, get an in-line sensor version.

2nd. Thermostats for our YJs are not all the same. SOmetimes you can go through 1 or two new ones just to find one properly produced.

Which brand and specs is the T-Stat you chose? Did it have a provision drilled into it to assist in letting any trapped air pass through?

Since you overhauled your entire system for this conversion, i would totally bet it's either the thermostat, or air in your system (or a combination of both) that are causing your issue.

I know some here (quite legitimately might i add) are going to come in here with a, "see... e-fan issues". They aren't wrong but not entirely right either. In your case, it wasn't just an electric fan you added so i think there are a couple things causing this issue (specified earlier in this post).


EDIT: while we're on the topic of what you added, what make and model is the waterpump you added? What was the make of the fan? You sure you installed it correctly? Some fans are pusher fans, some are puller fans... some are both.
 

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Make sure you've got the right water pump.
Exactly - ^^^

Motorad thermostat is a bet, drill a 1/16" weep hole in it

After that, sell the electric fan on Craigslist and put an oem belt fan in.

Why did you think you needed an electric fan if everything was fine.
 

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I'm an anti electric fan person but I don't think that's the problem unless it runs cool at speed and only overheats when stopped. I think you need to specify in more detail when it overheats though. Overheats in the garage after idling 5 minutes, overheats on the highway, and overheats in slow moving traffic are all totally different scenarios.

I'd personally start with checking a few things for free as they can affect all conditions.
1. First is burp the system. Jack up the front as high as you can or park on a steep hill and burp the system again. It wasn't a 4.0 but I burped my system 5 times and couldn't figure out why I'd overheat in the garage. I had already added 2.5 gallons to the system. Jacked the front up a foot and got about 1.5 gallons more in and the system works amazing now.
2. Make sure the e-fan is pulling air through the front and not pushing it.
3. Verify the specs on your water pump and make sure you bought one with the correct spin direction.
4. Verify your serpentine belt routing. Just because it fits doesn't mean everything is spinning in the correct direciton.
 

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I was for the electric fans but recently when back to the belt driven since I had the temp sensor go bad I didnt use a thermostat I used a switch and I couldnt get a good replacement. It would come on at 210 but I went through 3 and all would not shut off till 100 which caused over heating at speed. With that said when I was going through it I learned a few things and had mine to where on 37s with 4.10s I6 I could run the pretty steep grade on the mountain here at 117mph and not over heat. I only did it once.

As others said get a spal or flex-a-lite fan. You need atleast 3500cfm if you are in a hot summer area. I used a pusher and a puller since under certain conditions the puller just wasnt enough.

If you ask me now the e-fans just arent worth the trouble. But if thats what you want good luck. Youll get to learn about the cooling system,

Also dont take the thermostat out youll be back here with all kinds of weirds questions in a few weeks.
 

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Discussion Starter · #7 ·
UPDATE First, i want to thank Bruinjeeper, Timatoe, Fishadventure and waternut, thank you all for sharing your wisdom and confirming where my conclusions were headed.
i have gone thru 4 fans(all fitment issues besides the last)
2 t stats
1 waterpump possibly 2 (sounds like bearing are going)
i added a few pictures of the engine compartment. don't judge, the wiring is not complete i've got some jumpers roughed in as i finalize some system installs. as of right now 08/30/2021 1113 hours there is no t stat installed, no e fan, it crapped out, reference photo 4
waterpump and t stat are both from auto-zone pump is their name brand and motorad is the tstat 195deg.
if stage 2 is a brand than that is what i was sold thru Jegs. it was a push/puller depending on wiring. as far as the fan goes. its my daily driver so i cant keep having these issues so im going mechanical again for now.

It overheats in traffic and stop lights. in this SFV heat it stays around mid way. in the morning or at night it stays around 195

ive heard horror stories about overheating if not burped properly. so im going to spend some extra time with that right now
 

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I think going back to a clutch fan is the right move but I suspect the real kicker was just inadequate airflow from the e-fan. Looks like you have an aluminum radiator which should help a lot. E-fans in general are considered push/pull for marketing reasons but they're optimized and designed for 1 direction. If you choose the opposite direction, it works but at a reduced capacity. The only downside to going back to the clutch fan is your lack of a fan shroud but technically you needed one for your e-fan as well. The clutch fan can pull air from the edges of the radiator without a fan shroud but obviously not as well. The e-fan creates it's own fan shroud which usually only accounts for it's own diameter. For example...my radiator core (the center fin section) is 18.1" x 19.6" which is 355 sq inches (your radiator may be different). The area of a 16" e-fan is 200 sq inches so at best, the fan only cools 56% of the radiator at idle and slow moving traffic. Just something to consider.
 

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i agree with going back to mechanical fan for now.

But am curious if there still is any lingering issue. We might never find out if you switch back to a mechanical fan while doing a really good burp job and finally getting any air out of that system.
 

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UPDATE

t overheats in traffic and stop lights. in this SFV heat it stays around mid way. in the morning or at night it stays around 195
I assume that overheats in traffic means at low speed like under 25MPH. Overheating when stopped is self explanitory.

If this is the condition. You have a few possibilities.

A fan that does not provide enough CFM to cool your stuff.

A radiator or condenser that is too plugged air flow wise to allow your fan to work at low speeds.

A lack of proper fan shrouding including radiator shrouding to pull air with velocity through the radiator itself rather than anywhere else randomly. This really matters and is so often overlooked.

You sound like you have an adequate cooling system but no air flow/fan help when idling or very low speed which is the same.
 

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Discussion Starter · #11 ·
Update to the update...So i attached another picture showing the fan assembly w/shroud.I wanted to clarify something, when the fan was installed it worked really well. Had a bit of trouble with the adjustments but when i got it dialed in it would turn on at 210 and even though the controller stated it would shut off 10 degrees below the on setting mines was roughly 20 degrees. These fans just kept blowing up on me and the electrical was sound.
So there was a fan shroud which you can see in the attached photo.
Boojo, you are correct. i would go as far as 35 mph and under would overheat
The Fan claimed it pulled 2150cfm. Per his post above, Siva claims a min of 3500. I don't know this to be true or false but my gut says he's correct. The engine compartment seemed hotter than normal with the electric fan installed.
The radiator is relatively new and got an extreme flushing. Why flush a new radiator? I had a brain fart and allowed a pimple faced kick at autozone to sell me on the orange radiator juice when i knew it should be green. Well rumor has it the two dont mix, hence the flush



It got a flex o lite 17" inch reverse rotation silver flex fan with 2" spacer no fan shroud. i use to be able to run this in the desert crawling 100+ degrees no fan no shroud and the aluminum radiator in the photos and the temp wouldn't Flinch



Waternut, it was the burping. it wasnt until i read your post could i even imagine that much air in the system. Im testing it out in Gorman this sunday if i can get away


Last question, i developed some popping on deceleration, with the overheating issue i thought head gasket. Is this possible? i assume i would loose rad fluid and that wasnt the case. i most likely have to re-torque the pacesetter headers i installed.



Thank you all and im Proud of yall staying on track and not turning this into a witch hunt
 

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I think the popping on deceleration is typically caused by some unburned fuel detonating in the exhaust pipe. This in turn is actually caused by leaks in the exhaust or intake causing extra fresh air into the exhaust. The fresh air has more oxygen which allows the unburnt fuel to detonate making the hot exhaust even hotter. A cat and baffled exhaust help minimize this popping sound even if it's present but a cat delete and straight through style muffler can really highlight the problem even though they aren't the cause of it.
 

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Discussion Starter · #13 ·
Update to blah blah blah....

Thank you all for your patience, ive been traveling with work for the past couple of months. I promised myself i would continue this thread through resolution as there is no definitive answers to this overheating issue. I'm positive now there is not one solution(/rollseyes...stating the obvious)

So now I'm looking for reassurance to my thought process. Cooling system is back to stock minus a three row aluminum radiator and no shroud.

  1. 195 Deg. thermostat new and test in a pot of hot water(temp confirmed with external kitchen thermometer). Also installed with spring to block.
  2. Water pump is new and functioning. Thermostat was removed and saw flow of water across the top of radiator. We have a reverse pump system so I'm thinking flow should be from driver to passenger while standing in front of the vehicle(Mines is from passenger to driver). Diagnosis-wrong water pump!?!? I have a new one on stand-by with an R stamped on the impeller(did not confirm this with currently installed water pump).
  3. on the chance this water pump is correct than its a matter of bleeding the system. OMFG ive done this 3 times and air is still burping out. I'm burping with the front of the vehicle raised about 1 1/2' above the rear, radiator cap off and coolant topped off. i see the coolant raise and spill out if ive overfilled it and bubbles follow. if i haven't overfilled, it will raise to just that point, bubbles happen and level drops. now based on previous post from those with much more knowledge than I, this can be an excruciatingly painful process. key is patience.

Please for the last time provide some guidance and i promise to bury this...
 

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There are two things that I look for when burping the air from an engine that are good indicators that it is REALLY DONE. Both heater hoses feel the same temp when felt with your hand and also both radiator hoses feel the same temp by hand also. The radiator hose one indicates that the thermostat is fully open. When you let an engine run the top hose will get hot for a little ways when the thermostat is not really open, the radiator and lower hose will still be cold. When the thermostat opens the first time the lower hose may get hot and you think yea baby.... Nope, not really. The thermostat will cycle open and closed for a while until the engine has run a long time. The lower hose and radiator will feel cooler when it cycles shut again. An engine may run for up to an hour before it is fully open if you are doing it at idle. I let any engine run for at least an hour after I service the cooling system in any way.


Are you using a coolant fill funnel such as a Lisle 24680 when burping it? That is a game changer and the only way to do it. I have done this a long time for a living and fight air pockets at least once a week even with all my experience.

You caught on to the correct thing though. Patience.
 

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Try running evaporust through the system. It'll eat any rust and not eat normal metal. I had high NOx and the cause was a rusty block. You can inspect the condition of the block through the thermostat to see how bad/good the block is. Rust acts as a very strong insulator preventing heat transfer from the block to the coolant.

Though if you only have high temperatures in your coolant, it may be only a heat dissipation issue. Still my engine coolant runs lower too after my evaporust treatment, probably had grime on my radiator
 

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Try running evaporust through the system. It'll eat any rust and not eat normal metal. I had high NOx and the cause was a rusty block. You can inspect the condition of the block through the thermostat to see how bad/good the block is. Rust acts as a very strong insulator preventing heat transfer from the block to the coolant.

Though if you only have high temperatures in your coolant, it may be only a heat dissipation issue. Still my engine coolant runs lower too after my evaporust treatment, probably had grime on my radiator
This is a false claim. I have used Evaporust a lot. I restore a lot of vintage hand tools such as wood working planes, egg beater drills, lots of stuff. It is a good product. Be careful with it. Nothing can remove rust without there being a risk to the real metal under it. I had evaporust make me cry when I dipped a vintage about 1860 ish hand plane in it for a couple of hours. Just saying. Real world experience. I use the stuff, it works well, it can cause harm to metal. I promise you that.
 

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Discussion Starter · #18 ·
Are you using a coolant fill funnel such as a Lisle 24680 when burping it? That is a game changer and the only way to do it. I have done this a long time for a living and fight air pockets at least once a week even with all my experience.

You caught on to the correct thing though. Patience.
Boojo35, You knocked sense into or jarred some brain cells loose with this gizmo you mentioned. Id get frustrated and call it quits. id come out the next morning and have to fill the system more then it lost or so it felt. Well i purchased this gizmo to see if air was leaking back into the system on cool down. Headed out in a few, ill let you know.

Thanks for the Brain food Bruin.
 

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I did not realize that thermocure is made by evaporust. I have never used the thermocure, only the regular evaporust, so my above statement saying I know it can have effects on metal may be false.

My experience with Evaporust is it can badly discolor metal which if it is something you really care about, you have done damage. What I use if I do not want to discolor something such as an old tool is plain old white vinegar. It is slower but it does a fantastic job. It also costs way less.

Here is my experience with flush products. My wife had a car when we dated and first got married that the cooling system was pretty nasty. A flush product was used. It later developed a head gasket leak from a cylinder to a coolant jacket. The aluminum head was etched and corroded too deeply to even be resurfaced. The etching was wider at the coolant passage side than at the cylinder. It really appeared that the only cause could be the residual flush chemical and it not being properly neutralized.

Another experience is we had an abundance of Hyundai and Kia vehicles with heater core failures (leaking). The common denominator was all of them had coolant flush services in their history.

I am not saying all flushes and products are bad but they IMO need to have a process to neutralize the flush chemical when finished. I know that my .02 may not be worth much and it goes against some of these companies claims but part of getting smarter as you get older is learning from your experiences. I have chosen to trust my own experience as it applies to my own world. I hate breaking down in a vehicle.
 
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