hey orgers, over the past few months, my cooling fan has randomly began to make the whole car vibrate when it activates, if you did not listen to the engine bay, or look at the tach, it feels as if the car is about to stall out, but the idle is fine, and a few weeks later, it went away.

so i thought, wow it fixed itself. wrong. ff a few weeks later, its back. not as bad (noise wise), but it still randomly made the car feel as if it were vibrating.

i checked to see if anything was in the way of the fan spinning, nothing.
i waited till it made the noise, and turned the car off, and spun the fan manually, i felt nothing wrong, it freely spins. there is a bit of slack i guess you can call it, the fan can slide front to back, i'd say it has about 7/32 to 1/4 of an inch of play. dont know if thats normal. *note*, the car has not overheated even when this happens.

so ff even more to the other day. im in traffic, and its hot out. my car begins to slightly overheat. the fan turns on and off, and its still vibrating, when it turned on, it now overheated...slightly. if i am moving, the temp goes back down on its own. until i was in traffic for a while.

the car began to overheat, the fan turned on. it began to vibrate.
i turn the a/c on so the higher speed on the fan activates, and the temp sloooowly goes back down.

then after a few mins, even with both fans on, the temp slowly climbs back up.

i replaced the thermostat last year, i dont believe its that.

the strange thing is, the only time the car overheats is when the fan vibrates upon activation. if it doesnt vibrate, the car doesnt overheat. if the temp goes up, i know 100% of the time the fan will vibrate when it turns on. which makes me believe i need to replace the fan motor. is this a correct assumption?

 

I guess first make sure that the fan assembly bolts are good and that there is no movement with the fan assembly.

The fan is workin so thats a good sign. And the car hasnt overheated...the temp needle jus goes up a lil bit if i am reading u correctly.

Is the ECTS original? Seems its working to me along with the cooling system in general.

Is it the original radiator? A new one is like 150 or less on ebay. U got the cash man jus get another one lol

If its jus the bolts, then replace those. But if it takes both fans activated jus to cool the engine, then the fan is starting to wear out.

 

goomzthegeneral, you are correct on your asumption. There should be absolutely no detectable wiggle in the fan blade. Replace that motor.

But you also mentioned something that did not sound right. Quote: "i turn the a/c on so the other fan activates". Both fans are supposed to run at the same time. NEVER one only.

The fan motors are 2 speed motors, high and low speed. When you turn on the a/c, both fan motors should spin at low speed when you press the a/c on button. When the engine coolant temperature reaches approx 200 degrees, the fans run at high speed.

When you don't have the a/c on, both fans will spin when the engine coolant temperature reaches approx 200 degrees. The fans kick into high speed when the coolant temperature reaches approx 220 degrees.

 

everything is tight assembly bolt wise. you are correct, the needle slightly rises. the ects is most likely original. the rad looks factory, but the fins are in good shape. no visual rust or corrosion on the inside when the rad cap is opened.

 

the fan motor assembly has somethign to do with the wiggle in the fan blade? just as i read what you typed about "the other fan activates" paragraph in your reply, i realized that they do both work at the same time. my mistake. will edit that out.

i understand what you are saying about the low/high fan speed settings. is it possible for one of the speeds to burn out, or stop working, and it only go into the other speed? can that cause my slight temp rise? and the fan play cause that crazy vibration?

 

There should be zero play/wiggle in the fan blade. When it wobbles, it makes noise.

It is possible for a motor to not work on one of the speeds. When the fan blade wobbles, it is usually because the bearing at the back of the motor (the non fan blade end) has gone bad. This is also the end where the brushes for the motor are. The extra movement rapidly wears out the brushes.

The motor, as I said, is 2 speed. To accomplish this, the motor has 2 sets of windings on the armature, and each winding has a pair of brushes. A regular motor has just one pair of brushes.

Besides the fans, it almost sounds like the radiator might also be low on coolant.

I posted some pictures of a bad motor that I took apart:

http://forums.maxima.org/5th-generat...ed-8-pics.html

 

i understand what you are saying, i wasnt sure if the play in the fan was normal or not, since it is not much. since it wobbles (randomly) that can cause my slight temp rise when the fan is activated? that makes sense, when the fan works properly, the temp is fine as well.

 

+1 with Dennis: Whichever one of your fans has the play in it needs to be replaced ASAP. It is just going to keep getting worse until it fails, flies apart, and busts up other things. The entire fan assembly comes off by unplugging two connectors and undoing two bolts that hold the fan frame to the radiator; then the whole assembly lifts right out. I would look for a replacement assembly in a JY first - probably least expensive way out.

 

bob and/or dennis

should i replace this
http://cgi.ebay.com/ebaymotors/RADIA...Q5fAccessories


or do i need this whole assy
http://cgi.ebay.com/ebaymotors/Dorma...Q5fAccessories

im decently mechanically inclined, i know i can replace the motor at home.

 

Dennis hit the nail on the head with everything!

Do you want to spend 70 or 115? Remember, both motors are aging. Might be worth the extra few $$ to have the whole assembly replaced, you get 2 new fans.

Sort of the same as with headlights, when one side blows, the other isn't far behind.

 

this is true, i believe i know what i have to do. sigh, another expense that is not a mod or upgrade. lol.

 

If you can get the fan blade off the old motor with no problem, fine to just replace the motor and save a few bucks. Personally, I would try a JY assembly first - there tend to be lots of 4th gens around to pick from.

 

i was thinking of this, but i dont want the same thing to happen to me on a used one

 

its the fan motor it become loose i change mine cuz that happen 2 me

 

It seems to be the correct one, but I think that you can get it for $60 at autozone, which is where i have bought several of them. The fan blades are a pressure/friction fit, you just pull it off.

If you want to replace the entire assembly, that's your choice. For the most part, I don't believe in replacing a working part. The only thing is that the picture is not exactly like my 97. The picture shows one fan blade with more fins than the other. Also one fan motor is covered with a heat shield, which may not be a bad idea. But then, you may not get what the picture shows.

 

i think i saw it for $60 as well from autozone.

and yeah, i agree with you on the ebay pic. my budget tells me the fan motor.

 

update:

i disconnected each fan when it began to vibrate, and it is the passenger side motor. will be replacing asap! thanks guys.