Novak Conversions Jeep Wrangler TJ engine mounts

Fan Noise

JDS123

JDS123

TJ Expert
Original poster
Supporting Member
Joined
Feb 24, 2016
Messages
3,281
Location
Illinois
Hi all,
The fan on my jeep works perfectly fine and my engine always stays cool. While I wish I was happy with that, I'm not. The stock fan on my 4.0 is driving me crazy when driving around with no doors. It is so loud that every time I rev the engine over 2000 rpm I want to stop and rip the fan out. My driving style and shift points completely change when the fan is on versus when it is off. Driving when the fan is off is a lot more enjoyable to me.

Is there anyway to make the fan quieter? I was looking at electric fan conversions but I've seen that they are ecen louder. I'm not worried about HP gains, just noise.


Thanks!
 
When you talk about the fan being loud, is it a bad loud? What I mean by that, is does it sound like a whine or a howl as if a bearing is going bad? Or are you just talking about the fan getting louder as you accelerate? The latter is normal, and the 4.0 is known for having a pretty loud fan (especially under acceleration). However, I can't say I've ever heard of anyone as bothered by it as you seem. That's why I'm trying to figure out if you're hearing what we all hear, or if maybe you have a fan bearing that's going bad or something.

As far as an electric fan goes, some of them may be louder, but some may also be quieter as well. If you went with an expensive fan with good ball bearings, I think it would be reasonably quiet (i.e. a SPAL fan).
 
Chris said:
When you talk about the fan being loud, is it a bad loud? What I mean by that, is does it sound like a whine or a howl as if a bearing is going bad? Or are you just talking about the fan getting louder as you accelerate? The latter is normal, and the 4.0 is known for having a pretty loud fan (especially under acceleration). However, I can't say I've ever heard of anyone as bothered by it as you seem. That's why I'm trying to figure out if you're hearing what we all hear, or if maybe you have a fan bearing that's going bad or something.

As far as an electric fan goes, some of them may be louder, but some may also be quieter as well. If you went with an expensive fan with good ball bearings, I think it would be reasonably quiet (i.e. a SPAL fan).
Click to expand...

I'll take a video tomorrow. The noise just sounds like a fan noise to me. Sort of like rushing air. It isn't a bearing as a far as I can tell. It isn't a squeal or anything like that. I also just had a brand new fan clutch installed.

I get really annoyed when I compare it to the way the engine runs when the fan is off. It just seems so much more responsive and smoother when the fan isn't running. The engine definitely revs quicker and there is essentially so noise coming from the engine.

Jerry Bransford said:
Is the fan shroud intact and installed? Going to an electric fan would be a downgrade.
Click to expand...

I'd imagine it would be. Never had a reason for it to be taken off but to be honest, I've never really looked. The engine runs cool all the time and I wouldn't imagine it would if the shroud wasn't there.
 
Chris said:
When you talk about the fan being loud, is it a bad loud? What I mean by that, is does it sound like a whine or a howl as if a bearing is going bad? Or are you just talking about the fan getting louder as you accelerate? The latter is normal, and the 4.0 is known for having a pretty loud fan (especially under acceleration). However, I can't say I've ever heard of anyone as bothered by it as you seem. That's why I'm trying to figure out if you're hearing what we all hear, or if maybe you have a fan bearing that's going bad or something.

As far as an electric fan goes, some of them may be louder, but some may also be quieter as well. If you went with an expensive fan with good ball bearings, I think it would be reasonably quiet (i.e. a SPAL fan).
Click to expand...


Jerry Bransford said:
Is the fan shroud intact and installed? Going to an electric fan would be a downgrade.
Click to expand...

Ok here is a video I took:
This was all around 2100-2300 rpm

I can hear the fan over my exhaust throughout the entire rpm range. It's really really loud.
Is there any upgrade for fans? I don't necessarily need more airflow, just less noise.
 
xxdabroxx said:
What kind of fan clutch did you have installed? It probably isn't unlocking properly.
Click to expand...

The fan turns off completely or is quieter sometimes so I think the fan clutch is working correctly. About 75% of the time, the fan is as loud as it is in the video. I'll ask what brand fan clutch is in there next time I'm at the shop. But if I remember correctly, the fan was just as loud before I had the new fan clutch installed.
 
Next time the engine is cold before starting it, like first thing in the morning, try spinning the fan by hand to see if it is stiff or loose. It should be loose and tend to spin a little after you give it a spin and take your hand off. The fan clutch should only make the fan stiff and hard to turn when it is hot.
 
Jerry Bransford said:
Next time the engine is cold before starting it, like first thing in the morning, try spinning the fan by hand to see if it is stiff or loose. It should be loose and tend to spin a little after you give it a spin and take your hand off. The fan clutch should only make the fan stiff and hard to turn when it is hot.
Click to expand...

Judging by the video, would you say my fan is louder than most? I can't tell if I'm just being picky because I don't have another tj to compare with. And I'll check the fan clutch once the engine is cool. Just got back from driving it so it is pretty warm right now.
 
jodomcfrodo said:
Judging by the video, would you say my fan is louder than most? I can't tell if I'm just being picky because I don't have another tj to compare with. And I'll check the fan clutch once the engine is cool. Just got back from driving it so it is pretty warm right now.
Click to expand...
Way louder for sure, Compared to yours, mine is silent. I run topless/doorless year round. I thought you were posting a trick question at first, until I saw the vid.
 
Hmmm, is one of your idler pulleys or other serpentine belt pulleys either seized up or starting to get bad bearings? I say that because this could be related to the serpentine belt, not the fan.

Mine doesn't sound that loud at all, not by any means.
 
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