josephbow6

Hey guys, I've got an odd noise that I can't figure out that is coming from the engine area. Seems more like driver's side. Here is some background and additional info:

I replaced the water pump, timing belt, headgasket, tensionor, and other gaskets a few months ago. Before this time, I didn't notice this sound. The job went fairly well and gaskets seem to have held. I never overheat and other than a slow oil leak from somewhere, she runs pretty good and has very few other issues.

The noise kind of sounds like a knocking noise and is not completely steady rhythmic with the rest of the normal tics of the engine. If I had to demonstrate the noise with my mouth, it would sound more like 'tac-a-tac-a-t-t-tac-tac-a-tac-a-tac-a' or something like that if that makes any sense at all. Definitely not a ticking, clanging, banging, or otherwise.

The noise either goes away above idle or I just can't hear it any more. I only can hear it at idle.

It's also not very loud but PLENTY noticeable. For you audiophiles out there, the frequency of this noise seems to be around 500-600 Hz.

Now, my though was, 'Oh, I got a chinese piece of junk water pump and the bearing is just loose or something'. So, today, I replaced it with a Honda water pump. Got it all back together this afternoon and..... same noise!

It's not exhaust noise (I've had that problem and fixed it before) and it's not a heat shield vibration (familiar with that basic noise too).

I've been considering selling this thing lately but just can't put money in to a new car yet. I've got to get this thing together!

Thanks for any help you can provide.

I've also included a short audio clip taken from around the front left (hood closed). Let me know if it works.

ezone

I'd use a long screwdriver as a stethoscope, figure out where the noise is loudest.

Are all of the alternator mounting bolts and brackets tight?

josephbow6

Hey, ezone! I was hoping to have you chime in. I did snug those alternator bolts down pretty good but will check and properly torque them tomorrow (if I can find torque specs). I'll also grab a screw driver and check around while I'm out there. I may go ahead and take the alt/air and power steering belts off just to help us narrow it down.

Did that audio come through okay? The sound is more and more present towards the end of the recording.

ezone

Yeah but I'm on a crappy laptop, no 5.1 surround or anything like that.


I thought the rattle sounded like something sorta heavy and alternator just seemed about the right size. IDK, all I can do is guess from here.

Use the stethoscope.

Don't get the $2 stethoscope from Harbor Freight. I tried one, it's garbage.
The screwdriver or a wooden dowel works better than that thing.

josephbow6

Thanks for the heads up on the cheap stethoscopes. I'll use a dowel or screwdriver for sure. And, yeah, it does sound a bit 'heavy' which I'm glad of.

So, to help me sleep better tonight (hopefully), would it be your initial guess that this is not an internal issue and/or something that will do damage if I drive it? I've got a second vehicle so I don't need to drive it. Just curious.

I'll be checking tomorrow for sure though and get back to you.

ezone

I'd think an internal issue such as rod bearings would be somewhat consistent with engine RPM (crankshaft speed). Yours didn't strike me as being consistent with crankshaft speed.

HTH

josephbow6

Well, I got out this afternoon and listened around with this old plastic handled pry bar I've got. This was my first experience with this diagnostic method and it was pretty cool! I began listening on the passengers side of the engine just to get some base line listening in. I then went to the right side (looking at the engine) and then to the power steering pump. There was a real faint high pitched whirring noise coming from it and to my limited knowledge, it sounded pretty healthy. I then went to the alternator with my bar and it was giving me the most noise and seemed to coinincide with the audible noise I'm here about. I then listened to the AC compressor and the similar noise was there but I think it was less intense. After that, I listened around to brackets for these components and a bunch of random stuff just to get some practice in.

I then took off the power steering pump belt and turned her back on and did some more listening. same noises from the same places.

I then took off the ac/alt belt and turned the car back on. No audible noise after that. I poked around with my bar and heard some basic stuff but it wouldn't do that noise any more.

The pulleys for alt and AC both feel fine. No slop and they turn easily. Any guesses so far?

Also, how long can I have the engine running without the belts on? Just until the battery dies?

Thanks so much for any input!

ezone

Woohoo, you are on to something here!

With the belt off:
Spin the compressor pulley with your hand, spin it hard once and listen. It should be quiet as it spins. (I bet it isn't quiet. I bet it makes a rumble sound. Might not seem real loud, but it's there.)

Spin the alternator pulley hard and listen. It should also spin quietly --other than the sound of the brushes inside making contact.


If it does turn out to be the compressor pulley, Honda sells the pulley and clutch set separate from the compressor. I always prefer to repair the original compressor when possible because aftermarket reman compressors are garbage.

You can also use a shorter belt to run just the alternator and bypass the compressor.


Since that belt only runs the compressor and alternator, that'd be correct.


HTH

josephbow6

Thanks for your time, ezone.

I will check out the ac and alternator pulleys tomorrow and pay special attention to the ac compressor. It is original and I replaced the alt. in the last year and a half or so.

It's also good to know that I can get just a couple parts for the compressor if needed. I guess I'd get access to that by taking off the lower shroud?

If I can't hear any noises tomorrow, I'll go grab a shorter belt and try it for a while. If the noise is still not present, I'll feel real good about working on the ac compressor.

Thanks for pointing me in some logical directions. I'm still relatively new at most of this.

ezone

You can buy the clutch and pulley set #4, and you can buy the field coil #10 if needed.

http://www.hondaautomotiveparts.com/...2FC+COMPRESSOR



If you want to bypass the compressor using a short belt for a car without AC, I came up with this Honda part number 31110-PLA-E02

You can see a good portion of it by detaching the wheelwell splash panel, but I can't say if you would be able to get the thing apart and together without removing the freon and removing the compressor from the engine compartment.
There are snap rings, a puller, and setup with measuring involved.


HTH

josephbow6

Thanks for the homework, ezone. I wouldn't have minded looking those numbers up but I appreciate it all the same. So, IF the issue is the ac compressor, you think a pulley and clutch would cover it? Seems like it would need a new bearing or something too. Course, keep in mind that I've never taken one apart and don't really know what I'm talking about most of the time. And, what's a field coil do?

I looked at advance online and it looks like they carry the belt for no ac so ill pick it up in the morning after listening for noise.

It's inconvenient that the compressor may need to be pulled but not undoable. I've got manifold guages and can rent a vacuum pump down the road at Art Pancake's if/when needed.

So, ezone, what's it like being a Honda mechanic? I've considered that as a career before but don't know anyone to ask about it. Are you at a dealer or small business?

ezone

The bearing in question is built into the pulley.

If it were an internal compressor problem, I'd expect you to have bad noises only while the compressor were engaged (AC or defroster running), and probably an AC performance issue to go along with it.




From ehow website

Compressor Clutch
The air conditioning compressor has an electromagnetic clutch that can engage or disengage the compressor pulley. The compressor pulley always turns when the engine is running, but the compressor only runs when the pulley is engaged to the compressor driving shaft.

When this system is activated, current runs through the electromagnetic coil. The current attracts it to the armature plate. The strong magnetic pull draws the armature plate against the side of the turning pulley. This locks the pulley and the armature plate together; the armature plate drives the compressor.

When the system is deactivated, and current stops running through the electromagnetic coil, flat springs pull the armature plate away from the pulley.

The magnetic coil does not turn since its magnetism is transmitted through the pulley to the armature. The armature plate and hub assembly are fastened to the compressor drive shaft. When it's not driving the compressor, the clutch pulley turns on a double row of ball bearings.






Some people decide to ignore the AC problem and just run the short belt forever, fixing the compressor is not the cheapest/easiest repair in the world....and some of us grew up without AC in our cars.

Posted earlier today:

I work for a rather small Honda dealership shop.

josephbow6

Well, I put a new Gates belt on the alternator (without AC) in order to isolate the noise further. I've still got the noise. So, I guess the AC compressor was okay after all (thankfully!). The alt. that I put in was a reman. and that was about a year and a half ago maybe.

After putting the new short belt on, I also listened with my bar again and only hear noise while on the alternator.

What do you recommend?

ezone

When you loosened the adjuster and hardware on the bottom of the alternator, did the alternator move fairly easy without having to loosen the 14mm bolt on top? If so, that top bolt is not tight enough.




I had a 04 Civic this morning that had a bunch of warning lights on...SRS, CEL, and the red battery light (charging system warning light), maint light flashing. This thing was busy LOL.

It had a brand new looking parts store alternator, and it even stunk like a bad one....but it was charging, good volts and amps output.

It had a rumble as you gently blip the throttle, slightly above idle RPM it just did not sound right.

The upper bolt was not fully seated, it needed about one more full turn before it tightened against the housing and stopped the rattle. The bolt WAS tight, as in it took a lot of effort to get it to turn, so a torque wrench might have said it was correct when it clearly was not. (there's no way a torque wrench would fit in there anyway with everything fully assembled)

It creaked loudly when it moved. Like an olden scary movie castle door creaking.

It may have had galled threads, it may have damaged threads or something that caused it to require a whole lot of turning effort. IDK, IDC.

It didn't rattle after getting that bolt tight.

But....

The charging system warning light was still on........ because something (alternator problem?) has now apparently ruined the PCM. I can't tell if this happened before or after it got the new alternator though, and I don't know why it was replaced. I just know it's gonna be expensive if they want it fixed now.

I also figured out that the factory trouble tree for "diagnosing" why the warning light stays on does not lead to the PCM as a culprit in this particular case.
3 of us in the shop all verified the trouble tree is wrong.
No wonder it's called a 'trouble tree', it can really get you in trouble.

josephbow6

Great imagery! :-)

It's funny that you mention loosening the bottom hardware and then loosening the adjuster screw. I almost ALWAYS loosen both top and bottom and then turn the adjuster screw (which makes it real easy) until I can get the belt off. Like I've mentioned though, I'm pretty green at this stuff.

I'll double check the top bolt tomorrow. I'm just worried that I'll strip the threads in the bracket. I guess the worst that could happen is that I do and just have to replace it the bracket.

I'll let you know how it goes.

Oh yeah, my airbag light is on AGAIN. I'm glad that stuff is lifetime warranty. Last time is was the drivers side seatbelt buckle switch or something. This time there is a short in it (according to the code I pulled with the paperclip.

ezone

Yeah, if the alternator moves without having to loosen the top bolt, it's not tight enough. When that top bolt is tight, it's usually got enough clamping force to keep the whole mess from moving unless you beat it to death with a hammer and 2x4 to get it to move LOL



You could grab another lifetime warranty replacement alternator and see what happens too.

josephbow6

Yeah, whenever I put it all back together, I always tighten it all back up like normal. I guess I might just need a couple extra grunts on it.

josephbow6

I have been trying to remember where I got that one. I'll probably drive down the road tomorrow and just stop at our three parts places. From now on I'm getting Honda replacements. I've had way too many poor components like that.

josephbow6

Well, I went out this morning and tightened down both the bottom AND top bolts real snug. It's a wonder I didn't strip the threads out of either. I thought that fixed it for about a half minute and then the sound started up.

I called advance, AZ, and oreilly's to see if any of them had record of me buying the dumb alternator there and they didn't. They had my name and list of purchases, just no alternator. And IF I bought it at NAPA, I've got to have a receipt, which I don't believe I do.

Any tips? Should I bite the bullet and get a Honda one? I see their re-manufactured one goes for $242.62 and the new one goes for an astonishing $637.01!

Oreilly's has some piece of junk 'Altima' for $119.99, Advance has a few different options (all reman.), NAPA has some confusing listings of remaned Boschs going for more than a new Bosch.

What do you recommend, ezone? Sure, I could always go with the junkie AZ one and have a lifetime replacement but, I just don't feel like replacing it every few months. Or do you think I even need to replace it at all?

CraigW

iTrader: (1)

I ask my Honda tech once.......his recommendation was Honda reman.

ezone

Of course not. The Zoo here is known for losing all records of your purchases.

Is there a label/tag on your alternator? Any info there?

If the problem inside the alternator then sure.

But is it something else? Is the mounting bracket securely attached to the engine block? (5 bolts)



I work for a dealer. I need the cars I touch to STAY fixed. You should already know my answer LOL


AutoZone: Turning your Honda into a Kia one part at a time.



Some people have no issues with parts store stuff at all.
I think they can be hit-or-miss, but the track record isn't good enough for me to have confidence using their stuff in my work.
Plus, at the shop we can get labor cost covered if there is a warranty issue with parts from Honda. Parts stores usually won't cover a dime of labor if their parts crap on you.


I might even take a good used original unit over a parts store alt.

A reputable quality rebuilder should be able to overhaul an original unit with ease.....But don't bother with a cheap rebuilder.

We used to have a great starter/alternator rebuilder in my town, they wouldn't even think about trying to rebuild parts store units because they are usually crap. Retired and closed a few years ago.....Much to my dismay.
Now there's a place that uses the cheapest internal parts and turns your original unit into the equivalent of a parts store crap reman. I won't send any of my friends there, I recommend a place in the next town almost an hour away if they want it done right.


HTH

josephbow6

I'll pull that alternator Sunday when we get back from east TN and check for numbers and stuff. Hopefully it'll have an AZ number just so i can take it back. I'll also check that bracket and snugg them all up. I did have to take that off to do the head repair so it's always possible.

josephbow6

Finally pulled the alternator yesterday afternoon. I checked for labels and model numbers and all and there was nothing on it! Anyway, I also spun the pulley and listened with a socket extension and heard the rumbling that I am sure is the culprit. It is supposed to be pretty much silent right?

I'll likely pick up a replacement today or tomorrow and report back.

ezone

Yes, inasmuch as it should not spin with a rumble.

josephbow6

It was the alternator after all. I guess I've just never heard an alternator make that kind of inconsistent noise.

Thanks for your help, ezone. Next time I've got odd noises, I'm going to go straight to my pry bar and start listening around. Then start taking off belts. ( :

All is god now (for the most part).

ezone

YW.

Call it a bionic ear LOL