Whistling Sound?

[oiprocs]

When I accelerate in my Prelude I hear a whistling sound, and it feels like it's coming from the left side of the engine. I can't be sure because the sound isn't as noticeable if I'm just revving it; I have to be in gear to hear it, and even then it's like a low whistle, not a shrill.

I plan on taking it in tomorrow or Thursday but maybe someone can give me an idea of what to expect.

 

[JulesMaximus]

Probably a vacuum leak. Look for a hose that has popped off. Did you get a check engine light as well?

 

[Cdubneeddeal]

Could be the alternator or possibly a crack in your exhaust manifold.

 

[Sluggo]

Does it sound like of like........whoo whoo

http://www.youtube.com/watch?v...4uZPTo&feature=related

 

[atybimf]

I have a 1992 Prelude that does this too, except it sounds more like the noise is coming from under or behind me. The sound is only made at a certain point in my acceleration. If I keep my foot on the pedal at that point it continues to make the noise.

 

[oiprocs]

I took the car to a new but very well esteemed mechanic (or so I've heard) in San Diego. Along with an oil change, I had them check for the whistling sound.

Their diagnosis was that my alternator was the cause of the whistling. The owner (or manager) told me, for him personally, it isn't a problem and he would let it run until it goes bad for sure, but he said you can't really tell when it might go out.

The estimated cost was $190 for the alternator and $121 for labor. I declined to get it done since I figured I'd check it out first over here.

EDIT* I checked online and I found the alternator for my model at $186.

 

[Cdubneeddeal]

Originally posted by: Oiprocs
I took the car to a new but very well esteemed mechanic (or so I've heard) in San Diego. Along with an oil change, I had them check for the whistling sound.

Their diagnosis was that my alternator was the cause of the whistling. The owner (or manager) told me, for him personally, it isn't a problem and he would let it run until it goes bad for sure, but he said you can't really tell when it might go out.

The estimated cost was $190 for the alternator and $121 for labor. I declined to get it done since I figured I'd check it out first over here.

EDIT* I checked online and I found the alternator for my model at $186.

Glad I own an older VW.. Before you go out and buy a new alternator. Check to see if the regulator merely needs replaced. That'll save you tons of cash.

 

[oiprocs]

Would "check" imply something I can do on my own, or need I take it to a mechanic for that?

 

[alkemyst]

check would imply what a mechanic does really anyone could, but most would fail

Many autoparts stores, dealers, sears could check this for free/low cost. I didn't look up your vehicle, but not all have a regulator that's really user servicable. A dealer alternator is usually 2x+ more than the same replacement at an autoparts store.

rockauto.com I have had great success with on many parts, along with parts.com when I definitely wanted a factory part.

For an alternator on a honda, I'd check out the honda forums like clubsi.com and the like for recommended replacements.

 

[oiprocs]

Thanks for the info alkemyst. Brew me some chemical that gets 156465164156MPG, will ya?

 

[alkemyst]

It's more physical than chemical, but the most economical way would be: Link

 

[Zenmervolt]

Originally posted by: Cdubneeddeal

Originally posted by: Oiprocs
I took the car to a new but very well esteemed mechanic (or so I've heard) in San Diego. Along with an oil change, I had them check for the whistling sound.

Their diagnosis was that my alternator was the cause of the whistling. The owner (or manager) told me, for him personally, it isn't a problem and he would let it run until it goes bad for sure, but he said you can't really tell when it might go out.

The estimated cost was $190 for the alternator and $121 for labor. I declined to get it done since I figured I'd check it out first over here.

EDIT* I checked online and I found the alternator for my model at $186.

Glad I own an older VW.. Before you go out and buy a new alternator. Check to see if the regulator merely needs replaced. That'll save you tons of cash.

Regulator won't cause a whistling noise.

Most likely it's just harmonics at a particular engine speed/acceleration. Or it could be a slightly worn bearing on the alternator pulley. Either way not much to worry about at this point.

ZV

 

[alkemyst]

A regulator could cause the sound through the speakers. Many think they are 'hearing' the alternator under the hood when they are just hearing the sound in their speakers.

The charging system can be easily checked for problems electronically and physically while under the hood.

 

[oiprocs]

Ok, so I'm really dumb. Like really dumb.

When I bought the car, I noticed that the battery light would intermittenly flick on and off while I was driving; sometimes I could go a whole hour without seeing it, but it would never stay on, just flicker every now and then. The guy told me that the battery had just been replaced so it was just an electrical error.

Fast forward to my whistling sound, and I'm doing some research on the alternator. I found this on a site:

"The battery light indicates a battery charging problem. If the battery light comes on and stays on while you are driving, the most common cause is a broken alternator belt. Total failure of the alternator is another possibility.

The reason why your car can operate normally even though the battery light is on is because your car can run off the energy stored in the battery. Your car will run fine until the battery goes dead."

Soooo, sh!t. I guess the alternator really does need to be fixed? If so this sucks.

 

[oiprocs]

I bought a voltmeter from Radioshack to test out my alternator. I read on some site that if you check the voltage of the battery while the car is on, while revving to ~3000, anywhere from 13-14 volts means your alternator is fine.

I tested the car out earlier this morning, on DC, and the needle was in between 13-15. Too much fine print to see exactly where. I wondered if I needed measure AC, but when I did that it shot up right to 15, so that was useless.

Anyways, I guess my alternator isn't bad at all. I have 159xxx miles on the car, and I was flipping through the service records that the seller gave me and noticed that he had the alternator replaced at 148xxx miles. The whistling sound could just be normal to the engine, but either way I sure as hell am not going back to that "esteemed" mechanic.

I wish I grew up in a repair shop.

 

[atybimf]

I've been following this thread to see if you could figure it out because I have the exact same problem in my '92 lude. Nothing seems to be mechanically wrong with it (from what I can tell..I'm no mechanic though). The whistling noise during acceleration is going to drive me crazy though.

Let me know if you figure anything out.

 

[oiprocs]

Ok so I played hawk the other day and snooped around my engine for a good twenty minutes. Now I generally believe that the whistling noise is coming from the right side of the engine bay. Lo and behold, I can hear a hissing sound in that area, specifically if I point my ear at the alternator. I tried playing with the hoses in that area but I still hear the hissing.

So. Any thoughts?

Also, I need to get a new valve cover gasket to get rid of oil leak. Is this such a hard task that I would need to take it to a mechanic, or can I do it myself?

 

[exdeath]

Valve cover gasket is easy, but it may be time and labor intensive (esp if the intake is on the 'back' of a tilted engine) and result in keeping track of many parts you might not be familiar with (intake plenum and throttle assembly and assorted vacuum hoses, diaphragms, etc) in order to pull the valve cover clear. Just do it in a clean zero wind environment to avoid contamination of the head internals with dust/dirt/etc.

Does this whistling sound more prevalent first thing in the morning after the car has been sitting and cold? Squealing engine noises come from rotating parts like accessories (AC compressor, power steering pump, alternator) or idler pulleys.

Something you could check yourself is loosen the alternator bracket (if you don't have a serpentine belt tensioner) and remove the belt and turn all the accessories and idler pulleys by hand and feel for grit, resistance, shaft play, etc. You can also place the end of a large bar/dense piece of wood/pry bar/screw driver/etc to each pulley bolt or bracket while the engine is idling (with the belt installed of course) and hold your ear to the other end. If you find one, you'll know it, and when you rotate it by hand it will feel like it's full of dirt.

 

[oiprocs]

I always warm up the car for ~5-10 minutes before I take it out, but the whistling sound is not prevalent then, in fact I'd say it's more audible after the car gets going. It sounds just like a turbo, and is only there when I throttle. The noise is not really there at low RPM's, but at higher RPM's, I can hear it, and should I depress the clutch, the whistle disappears right away.

 

[atybimf]

Originally posted by: oiprocs
I always warm up the car for ~5-10 minutes before I take it out, but the whistling sound is not prevalent then, in fact I'd say it's more audible after the car gets going. It sounds just like a turbo, and is only there when I throttle. The noise is not really there at low RPM's, but at higher RPM's, I can hear it, and should I depress the clutch, the whistle disappears right away.

same EXACT thing with my 92 Lude...and it annoys the hell outta me

 

[oiprocs]

Originally posted by: atybimf

Originally posted by: oiprocs
I always warm up the car for ~5-10 minutes before I take it out, but the whistling sound is not prevalent then, in fact I'd say it's more audible after the car gets going. It sounds just like a turbo, and is only there when I throttle. The noise is not really there at low RPM's, but at higher RPM's, I can hear it, and should I depress the clutch, the whistle disappears right away.

same EXACT thing with my 92 Lude...and it annoys the hell outta me

Ironically, your post brought some joy to my face. A mechanic told me the alternator was causing the noise, yet it only has 12K on it. I assume your alternator is running fine, so that finally gives me some relief.

 

[atybimf]

Originally posted by: oiprocs

Originally posted by: atybimf

Originally posted by: oiprocs
I always warm up the car for ~5-10 minutes before I take it out, but the whistling sound is not prevalent then, in fact I'd say it's more audible after the car gets going. It sounds just like a turbo, and is only there when I throttle. The noise is not really there at low RPM's, but at higher RPM's, I can hear it, and should I depress the clutch, the whistle disappears right away.

same EXACT thing with my 92 Lude...and it annoys the hell outta me

Ironically, your post brought some joy to my face. A mechanic told me the alternator was causing the noise, yet it only has 12K on it. I assume your alternator is running fine, so that finally gives me some relief.

haha well It's running fine as far as I know..and I'm taking it into a mechanic in a couple weeks for something unrelated so I'm gonna ask him if he has any idea about the noise

 

[DOTC]

My mechanic buddy of mine told me that "noise" problems are the biggest PITA. he wouldn't even touch them.