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Pontiac Sunfire, Engine, Sedan
#1 of 10 need advice on possible causes
Aug 23, 2002 (1:14 pm)
I got an email from my g/f saying she had a problem with her car listed below. She described a whining sound when she is at idle..this whining sound goes away when you speed up. I drove her car and could hear the whining sound in the cabin. I even popped up the hood and had her hit the gas a little when the car was parked. I heard the whining sound..it sounded like it was coming from the belts. could this be the problem? she hasn't had a timing belt replaced and the car has 80k miles. I don't see any broken belts though. here's her email about the problem she had. any advice on what to look for would be greatly appreciated. I read from others that this model car has head gasket problems, but I don't think the whining sound has anything to do with that I hope.
I'm having problems with my
car this morning though! I would really like it if you would come out here
when I get off at 2 (or before even, if you wanted)and drive it around the
block & look at it for me. (I don't have my cell phone with me, and I'm not
confident that I should be driving it.) It's making a strange noise at low
speeds, it seems to happen when the RPMs get around the 1 mark. It sounded
normal at high speeds, but in stop and go traffic, it makes sort of a
whirring sound like maybe it's idling too high or something like that. Car
trouble is just what we need when we're about to drive to Florida. I really
think I need to get my car totally checked out before we go, because it's
never had any major maintenance done on it and it's over 80k miles now. But
I'm terrified of getting suckered for thousands, so will you please, please
help me figure out where to take it and what needs to be done. I don't mind
if the maintenance is expensive, it will be cheaper than waiting until it
breaks down or worse yet dies altogether and I have to get a new car. I'm
pretty stressed out this morning lol. Hopefully it is something minor, but
I'm worried because I've never had anything done to it and I'm afraid it's
gonna cost a lot.
#2 of 10 maybe it's alternator whistle or fuel pump whistle
Aug 23, 2002 (7:24 pm)
if it's the fuel pump transmitting noise along the chassis, it can whine for many thousands of miles more before it counts. if it's the alternator, it's normal wear, an indication that somebody needs to look at it one of these days. it would be bearings in either case, and any competent mechanic can use a stethoscope or even a long-handled screwdriver to pinpoint the noise area and determine if it's a present danger.
around 1000 RPM is about the point where an alternator is really catching up and putting power into the system instead of just holding even with the engine's computer, injectors, etc. demand for power. so that might indicate front bearing issues starting, or possibly an open-failed diode making noise, the "noise-emitting diode" can be real and not just an old tech's tale at current.
it could also be irregularities (as in cracks and pits) on a belt, but a visual and finger-rub inspection when everything is turned off and all sets of keys are in your pocket will find that.
my bet is on the alternator. if it's loud enough to get your attention, it ought to be checked. cost is variable... big SUVs with big engines and big towing electric systems are expensive, more normal passenger cars' alternators are often around $50-75 exchange and from 1/2 to 1 hour of mechanic time to replace them. any external regulator and the pulley should also be inspected, along with the drive belt, at the same time.
Aug 23, 2002 (11:15 pm)
It sounds like the alternator bearings are going bad. Time to change it out before it locks up and melts down a belt. Easy way to check it is with a broom stick or something like that put the stick on the body of the alternator while the car is running and then put your ear on the end of the stick. You can clearly find the noise that way for sure.
Aug 24, 2002 (6:34 am)
Thanks for the advice. I think I'm going to take her car to a shop to get the timing belt replaced since it's been six years, 80k miles, and replace the alternator at the same time. or should I have the mechanic just replace the alternator bearings? I researched on the internet that you could just replace the alternator bearings for $6 but since the car needs a new belt. I might as well leave that up to a mechanic too. does anyone know if a shop or dealer shop gives a core value for the old alternator? I saw a couple of websites that the old alternator is worth $55. Since I'm going to get the timing belt replaced, I've read that the water pump should be replaced as well for preventive maintence. what do you guys think? anything else to replace while the timing belt is off?
#5 of 10 go for a rebuild
Aug 24, 2002 (11:48 am)
just bearings is bad economy. you will also have wear on the commutator contacts, the brushes, and the heat/cold cycles will have at least deteriorated the insulation on the diode banks, if not gotten the diodes close to failure. rebuild parts kits start at a few bucks more than just a bearing pack, and it's worth shotgunning all the wear elements.
a good mechanic will also check the coil insulation and take a cut on the commutator to even up the contact surfaces with a lathe.
these days, it's much more common, though, for the shop to put in a rebuilt unit and send yours in as a rebuildable core, for which they get a whopping couple of bucks. some rebuilders are good, some aren't, and mostly it's a regional industry. ask 'em to put in a GOOD one, not a CHEAP one.
#6 of 10 update..alternator replaced; another sound appeared, help
Sep 01, 2002 (5:28 pm)
the help here has been great. I decided to replace the alternator myself. It didn't look too difficult, it was just a swap out. Well, here's what happened. On friday, I took the bolts off of the alternator. The b positive connection ring terminal ended up breaking off. My g/f freaked out. After I fixed that with a new ring terminal and crimping it, the serpentine belt took awhile to put back on all the pulleys. however, the whirring sound from the old alternator is gone. Eventually I got the serpentine belt on but there is a new sound coming from the belts. I checked the alignment of the belts. They are in perfect alignment. The tensioner bolt is tight. The tension of the belt is tight. I pressed with my thumb. I don't know where this sound is coming from? it's either the belt or the pulley. The serpentine belt is only a year old and it's not glazed. my poor g/f is stressing out over this. Would belt dressing apply for a serpentine belt? It seems like once I fix something..something else happens. It sounds more like a screeching sound you can hear at all speeds. please advise on this.
Sep 01, 2002 (6:15 pm)
1: The noise is probably the reman alternator. Is is a quality unit or a Pep Boys cheapo? Use a piece of garden hose as a stethescope to locate the source of the noise. Obviously, be careful around moving parts.
2: If you didn't solder the new ring terminal (as you were advised in the other topic you made regarding this), it will fail.
#8 of 10 serpentine belt screech
Sep 01, 2002 (7:50 pm)
I tried emailing you but my internet service couldn't send the email. By the way, thanks for your post. I'm sorry, I didn't get to do the soldering. I never did it before. I actually looked all into it yesterday. There was alot of information about it. I actually went to napa to buy a soldering iron and solder. Advanced auto parts and autozone didn't carry a soldering iron or gun. I did find an auto electric builder association website advising to use 97% tin instead of 60% iron but all I could find was the 60% iron solder in the stores. However, when I asked the Napa guy about it. He said to crimp it, splice the wire, and tape it. He advised against soldering. My g/f was with me when he explained it and she didn't want to do the soldering. I think she was afraid I was going to melt the copper wires. I ended up using a wire cutter to cut out the old metal ring terminal and pushing the wires through the new ring terminal and crimping it.
However, here's how everything started, I actually started working on my g/f alternator last friday afternoon around 6pm because she complained of a whirring sound at low speeds for a week. I checked her alternator and indeed hear the whirring sound from the alternator. I consulted edmunds and the posters advised the alternator bearings were bad. I consulted the chilton's manual for her car and it wasn't that tough of a job I thought. I have taken out an alternator before on an old 87 toyota. So I thought it wasn't a bad job to do. Everything was a piece of cake removing the alternator except when the ring terminal broke. My g/f got stressed out then, she remembers when I broke my brake line from my car.
The alternator I bought is a remanufactured Duralast from autozone with a limited lifetime warranty for 119 dollars. It's one thing when the whirring sound need to be fixed with another alternator. Now the screeching sound. When I was putting in the alternator, I had problems getting the serpentine belt around the alternator. I thought the belt had slack somewhere on the lower pulleys so I ended up taking off the entire serpentine belt and putting the belt around each pulley tightly. I thought about putting a new serpentine belt but the belt was only a year old and no visible cracks. When I did this, I turned the tensioner and put the remaining belt around the new alternator. When I had my g/f start her car, the belt was coming off around the crankshaft and the the idler pulley. I had her shut off the engine immediately. I aligned the belt back on the crankshaft and the idler and turned the tensioner to tighten the belt. I had her start her car again, and the same problem. The belt was coming off in the same two places. What happened was I had too much tension in the belt when she started the car in the first place and the second time. Did I glaze the belt when the belts were coming off? is this the cause of the screeching sound? I did finally get the correct tension on the belt and drove around the neighborhood. I heard a klanking sound. I pulled in my driveway and examined the belt. The belts were perfectly aligned around the pulleys except for the idler pulley which was hanging on the edge of the pulley but not coming off the pulley, the tension was perfect, but the tensioner bolt was dangerously loose. It was the washer around the tensioner bolt that was shaking around. I tightened the tensioner bolt and the washer. I had her drive the car back to her place and I followed her in my car. She said the whirring sound is gone, the klanking sound is gone, and now she hears a screeching sound. Great I think! Once I get rid of one sound another comes. I rode around in her car and I heard the screeching sound. The only thing I touched on her car was the serpentine belt and alternator technically so I took a look at the belt. The tension on the belt was tight, the tension bolt was tight, the belt was aligned on all the pulleys. Remember when I said the belt was hanging on the edge of the idler pulley but not off of it earlier? After driving 20 miles, now the belt on the idler pulley moved and is perfectly aligned. I'm dumbfounded. I don't know what is causing the screeching sound. I have researched the net. Some said it was a worn out tensioner, pulley, or the belt is not perfectly aligned and the a/c compressor is causing the screeching. I don't know what to look or do and my g/f is aggravagated by this. What to do? Replace with new serpentine belt? I heard of a belt dressing, I thought maybe since I took off the belt completely I needed to spray the belt to put back on the pulleys. now, I have learned that it is only for timing belts. please advise. Thank you for your help. it's been a tough weekend
Sep 02, 2002 (6:28 pm)
I have chronic squeakers in the past two Fords I have had, a little drop of oil on the back side of the idler pulley where the pulley meets the attachment post takes care of it until some car wash in the future. maybe wipe the back of the belt with a little isopropyl alcohol and a clean rag, see if you are getting any glaze off the back of the belt, the side that rides on the idlers.
certainly, this is all done with the engine off, you understand....
Sep 02, 2002 (8:52 pm)
Check your alternator to see if it is a new one or a re-man one. It should have a sticker on it that will say 100% new if it is. I have used re-maned units before with varying degrees of success, and would really recommend getting the new unit if you don't have it already. Just take the one you bought back and tell them that it makes noise. I am sure they will swap it out and let you upgrade to the new unit. Also get a new belt, just to rule that out as a cause, if the belt slipped out of the grooves it is supposed to ride in it can cause some strange cuts and abrasions. I personally only use Gator Back belts from Goodyear.