Strange high pitched whine at cold start up!
11-28-2010, 01:48 PM
#1
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Jan 2007
Location: Hays
Posts: 371
Likes: 0
Received 0 Likes
on
0 Posts
Strange high pitched whine at cold start up! Well guys I have been having a weird high pitched whine coming from my engine on COLD start ups only. It has been going on now for about a month or so now. The car has been parked for the winter and only gets driven when I go back home (away at college).
Well this past weekend my dad and I installed a 5 inch tach and a oil pressure gauge. Upon completing the install I had my dad stick his head under the hood and see if he could pinpoint the source of the loud and obnoxious whine. He instantly noticed that the plastic fin on the alternator was rubbing on the alternator itself. I turned the car off and looked at it closely and you could see about a 1/16 of an inch of material gone from the plastic fin. I applied a jolting pressure on the fin and you can hear the audible high pitched screech.
My questions are:
Why is it that it only whines at cold start up (30 sec. to 1 min), and then simply goes away?
What is causing it? Bearing failure?
And should I just replace the alternator or is there something else I should look into?
Thanks a bunch guys!!!
Devin
Well this past weekend my dad and I installed a 5 inch tach and a oil pressure gauge. Upon completing the install I had my dad stick his head under the hood and see if he could pinpoint the source of the loud and obnoxious whine. He instantly noticed that the plastic fin on the alternator was rubbing on the alternator itself. I turned the car off and looked at it closely and you could see about a 1/16 of an inch of material gone from the plastic fin. I applied a jolting pressure on the fin and you can hear the audible high pitched screech.
My questions are:
Why is it that it only whines at cold start up (30 sec. to 1 min), and then simply goes away?
What is causing it? Bearing failure?
And should I just replace the alternator or is there something else I should look into?
Thanks a bunch guys!!!
Devin
11-28-2010, 06:31 PM
#6
I had the cooling blade rubbing the housing on the alternator too. The main bearing on the front of the armature that is supposed to fit tight in the front aluminum housing, no longer fits tight and the entire armature and bearing assembly has walked back a bit. Now you have the cooling blade rubbing making that nails on a chalkboard screech.
Disassemble the alt and weld some "build" in the the front housing where the bearing fits in and machine it so the bearing fits rather snug. Reassemble and its golden. Or just replace the entire alternator. If you dont want to weld, you might be able to put some JB weld in there. Just whatever it takes to tighten that bearing in the front housing.
Disassemble the alt and weld some "build" in the the front housing where the bearing fits in and machine it so the bearing fits rather snug. Reassemble and its golden. Or just replace the entire alternator. If you dont want to weld, you might be able to put some JB weld in there. Just whatever it takes to tighten that bearing in the front housing.
11-28-2010, 07:58 PM
#7
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Jan 2007
Location: Hays
Posts: 371
Likes: 0
Received 0 Likes
on
0 Posts
^^^^ Nails on the chalkboard screech nails it! Its horrible!
I have never pulled an alternator apart. Is it pretty straight forward or is it best to just replace it rather then messing around with pulling it apart and tightening up the bearing?
I have never pulled an alternator apart. Is it pretty straight forward or is it best to just replace it rather then messing around with pulling it apart and tightening up the bearing?
Trending Topics
11-28-2010, 08:14 PM
#8
Going from memory here.
Take the big nut off the front and pull the cooling blade. There are 3 spacers all different thickness. Take notes of these for reassembly. Pull the blade.
Remove the 4 main screw from the back side. Pull the rear housing off and dont damage the brushes. I think there are several screws to remove to get the windings out. Remove the winding then you are at the front housing.
Chances are you can pull the armature with the attached main bearing right out of the front housing. Again this is where the problem is. It should be a tight fit.
The whole thing is simple nuts and bolts to get apart and intuitive.
Putting it back together is a bit more tricky due to the spring loaded brushes. You have to shove the brushes in their housings and hold them back with a pair os small allen wrenches or pins. The wholes where you insert the pins can be seen on the back. Reassemble then pull the pins and the brushes will make contact with the commutator.
Take the big nut off the front and pull the cooling blade. There are 3 spacers all different thickness. Take notes of these for reassembly. Pull the blade.
Remove the 4 main screw from the back side. Pull the rear housing off and dont damage the brushes. I think there are several screws to remove to get the windings out. Remove the winding then you are at the front housing.
Chances are you can pull the armature with the attached main bearing right out of the front housing. Again this is where the problem is. It should be a tight fit.
The whole thing is simple nuts and bolts to get apart and intuitive.
Putting it back together is a bit more tricky due to the spring loaded brushes. You have to shove the brushes in their housings and hold them back with a pair os small allen wrenches or pins. The wholes where you insert the pins can be seen on the back. Reassemble then pull the pins and the brushes will make contact with the commutator.
Last edited by wrd1972; 11-28-2010 at 08:35 PM.
11-29-2010, 10:29 AM
#10
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Jan 2007
Location: Hays
Posts: 371
Likes: 0
Received 0 Likes
on
0 Posts
wrd1972 Thanks for taking the time to spell all of that out for me! Next time im back home I will pull it apart and see what I find!
Jaycenk- Thanks for the input and i will do this, but I dont understand how it could be a tensioner bearing if the alternators cooling fin is rubbing on the alternator housing itself... It makes more sense to me that the bearing in the alternator is loose like wrd1972 was saying.
Thanks again guys!!!
Jaycenk- Thanks for the input and i will do this, but I dont understand how it could be a tensioner bearing if the alternators cooling fin is rubbing on the alternator housing itself... It makes more sense to me that the bearing in the alternator is loose like wrd1972 was saying.
Thanks again guys!!!
11-29-2010, 08:23 PM
#12
wrd1972 Thanks for taking the time to spell all of that out for me! Next time im back home I will pull it apart and see what I find!
Jaycenk- Thanks for the input and i will do this, but I dont understand how it could be a tensioner bearing if the alternators cooling fin is rubbing on the alternator housing itself... It makes more sense to me that the bearing in the alternator is loose like wrd1972 was saying.
Thanks again guys!!!
Jaycenk- Thanks for the input and i will do this, but I dont understand how it could be a tensioner bearing if the alternators cooling fin is rubbing on the alternator housing itself... It makes more sense to me that the bearing in the alternator is loose like wrd1972 was saying.
Thanks again guys!!!
11-29-2010, 09:05 PM
#13
TECH Apprentice
Thread Starter
iTrader: (5)
Join Date: Jan 2007
Location: Hays
Posts: 371
Likes: 0
Received 0 Likes
on
0 Posts
^^^^^^^ No problem man. Its easy to overlook things!!! Again thanks for your input bro!
And Wicked I am seriously considering it. If I am pressed for time (like i usually am when i go home) I will more than likely just buy a new one and be done, but I still would like to tear apart the alternator and find out what the problem was.
Thanks again guys!
And Wicked I am seriously considering it. If I am pressed for time (like i usually am when i go home) I will more than likely just buy a new one and be done, but I still would like to tear apart the alternator and find out what the problem was.
Thanks again guys!
