now, what is this sound :banghead:

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diymirage

diymirage

HP@idle > hondaHP@redline
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this thing is getting under my sin

75 360, build into a 408 by MRL, a few thousand miles on the build
a while ago it created a slight oil drip, but ive been keeping a close eye on it, and she has not ran dry, not even low

last Monday I went on a trip, maybe 60 miles round, mostly highway

on the way over there, I ran 45-50 PSI oil pressure
on the way back, I noticed it was 35-40 under the same circumstances

today, I fired her up to jumpstart the lawnmower and I heard this



so far all ive done is check the converter to flexplate bolts, they are all good and tight
(the flexplate is new, less then 1000 miles on it)
 
I did put a new set of belts on there last week
ill pull them off, see if there is a change or not and report back

what are you thinking, waterpump?
 
diymirage said:
I did put a new set of belts on there last week
ill pull them off, see if there is a change or not and report back

what are you thinking, waterpump?
Click to expand...

No idea, but if it stops, at least you have narrowed it down as to where to look.. New belts, maybe too tight, might take the bearings out in the alternator.

You could try a shot of WD-40 in the alternator around the bearings before you pull them to see if it quiets down.
 
thanks for the quick reply guys, I pulled all three belts and the noise went away

I put the belt for the waterpump and powersteering pump back on and the noise stayed away, so it has to be the alternator or the A/C

I don't know if I can pull the A/C pump and just run some smaller belts for now (if it is the A/C pump)
if it is the alternator, ill just replace it


the good news is, can pull that rag out the filler tube and put the matches back down again
 
Put the other belts back on, give the alternator bearings a couple shots of WD-40. If that's the noise, it will alter it, or it will go away briefly.
 
I found a few belts that might work without the ac, I'll check on monday (just about to head out of town of the weekend)

Thanks again guys, I'll keep you posted
 
Well, there is one more test I think worth doing.
Put the alt belt back on, and verify the noise is still there. Then dribble some water onto the inside of the belt, as it passes over each pulley. Sometimes belts stick to the pulleys and make this unusual sound. The water will prevent that, and the noise goes away;just long enough to do the test. Then as the belts dry up, the sound comes back.
There is no cure for this that I know of (tried 'em all) except a new belt; and sometimes a new pulley.
 
Sounds like the belts, been seeing alot of that in the shop lately, even some of the new belts have been problematic
 
AJ/FormS said:
Well, there is one more test I think worth doing.
Put the alt belt back on, and verify the noise is still there. Then dribble some water onto the inside of the belt, as it passes over each pulley. Sometimes belts stick to the pulleys and make this unusual sound. The water will prevent that, and the noise goes away;just long enough to do the test. Then as the belts dry up, the sound comes back.
There is no cure for this that I know of (tried 'em all) except a new belt; and sometimes a new pulley.
Click to expand...

I can give this a try on Monday aswell
I have a can of something called "belt dressing" and it sounds like this might be one of the things it is intended to fix


replicaracer43 said:
Sounds like the belts, been seeing alot of that in the shop lately, even some of the new belts have been problematic
Click to expand...

all three of the belts were drive-rite belts, made by dayco
(not saying that is good or bad, but that is what they are)
 
In my experience Belt Dressings work too good. They stop belt slip, but they usually introduce aggravating sounds of their own.
If your belt sits way down in a pulley, it can start to rub on the bottom of the Vee. Then it slips, and glazes up the shoulders, and then you get other aggravating sounds.
Twin belts must be purchased in matched sets.The manufacturer selects matching length belts for you, and packages them up in sets.
To replace just one of a pair,invites noise as single belts are not sold to a specific exact length,which on single pulleys is no biggie. But on twin pulleys the longer one will slip as the shorter one is over tensioned to do all the work.
 
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Int
AJ/FormS said:
In my experience Belt Dressings work too good. They stop belt slip, but they usually introduce aggravating sounds of their own.
If your belt sits way down in a pulley, it can start to rub on the bottom of the Vee. Then it slips, and glazes up the shoulders, and then you get other aggravating sounds.
Twin belts must be purchased in matched sets.The manufacturer selects matching length belts for you, and packages them up in sets.
To replace just one of a pair,invites noise as single belts are not sold to a specific exact length,which on single pulleys is no biggie. But on twin pulleys the longer one will slip as the shorter one is over tensioned to do all the work.
Click to expand...
eating point on the twin belts
I did not know that (though I did notice they spin at different rates, since I always line up the marking, and they never stay lined up)

I guess I'll put one belt on and see how she sounds
 
Sounds like belt slip to me.
 
I think just for kicks I would pull the oil pump drive shaft and see what it looks like.
Sounds kinda like a belt noise, but the 10lb drop in oil pressure AND that sound?
Dropping the oil and seeing if it looks like pearl paint wouldn't be a bad idea either.
 
TrailBeast said:
I think just for kicks I would pull the oil pump drive shaft and see what it looks like.
Sounds kinda like a belt noise, but the 10lb drop in oil pressure AND that sound?
Dropping the oil and seeing if it looks like pearl paint wouldn't be a bad idea either.
Click to expand...

maybe a dumb question, but what would I be looking for on that shaft?
 
Commenting on the oil pressure here, did you use a bunch o goo when you were fiddling with the filter plate?

I wonder if something got in the system.
 
Bad Sport said:
Commenting on the oil pressure here, did you use a bunch o goo when you were fiddling with the filter plate?

I wonder if something got in the system.
Click to expand...


hardly

I used the right stuff, once, about a month ago

other then that, I used gasket sealer (the red brush on kind) when I put the right angle adapter on


I don't know if this engine is still considered new enough that it is "settling", getting properly broken in?
 
Well, a rod-knock behaves very much the same.
So if you can't prove it's belts, It would be worth draining some oil out of it and checking it, like TB says ,looking for the telltale swirly pearl-paint. If you see it, the pan has to come off.
But I think you have proven the noise to be in the belts.
So it appears you might have two separate issues. Namely the noise, and the pressure loss.
So the first place to look for a pressure loss, is in the pump, or it's drive system.Since you say "same circumstances" this implies same oil temp, and same engine rpm. But if the oilpump drive is slipping, the oilpump rpm may not be the same as engine rpm, which it is supposed to be.So the first thing to check is the oilpump driveshaft.
You would be looking for severely rounded corners; and an uncompromised drive gear.
But I would read the oil first, it's much easier and quicker.If it's pure, then, move to the drive.
A 10 psi sudden drop in oil pressure would certainly get my attention, and I would not drive another mile until I got it figured it out.
FWIW, I've never seen a slipping hex-drive. Rounded corners; yes. Split oilpump D/S receiver;yes. Stripped gears;yes . Broken shank;yes. Slipping hex-drive;no!
 
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perfect, thanks

I do believe the noise has been proven to be related to the belt, but the oil pressure drop is certainly something that should not be ignored
ill pull the oil pump drive, either tomorrow or Tuesday
id have to see if I can scrounge up a timing light so I can make sure I put the timing right back here it was
 
I thought you popped the A/C belts off, and the noise went away? If not do that first.If those belts also run the waterpump, do not run the engine for longer than it takes to verify the disappearance of the noise.The moving index marks tells me the belts,or the pulleys,are not matched. Since rubber wears at a far faster rate than steel, I'd go with new a belt set; IF the noise can be proved to be belt noise.
But if the noise remains after the belts are off; go straight to reading the oil! Before pulling the drive. Swirly pearly paint is a for-sure sign of babbit material, and the sound says to me,rod. Just one.
 
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Yes, I did pull the twin A/C-alternator belts and it DID stop the sound
(The waterpump runs of a different belt)
I actually put about 20 miles on it, with those twin belts off and did not hear a peep

So I am sure it is a belt, alternator bearing or A/C bearing issue

But the lower oil pressure still bothers me, so I guess I will pull the intermediate shaft to check
 
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