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7-bolt Timing Belt whine?

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allthrottle

10+ Year Contributor
115
0
Feb 21, 2009
Houston, Texas
I'm looking for some suggestions on the source of this whine coming from the timing belt area. I've just changed the timing belt along with the idler and tensioner pulleys and auto-adjuster(Gates belt, Dayco components). Previous owner cut the B-shaft belt and put a bolt where the tensioner pulley is, but didn't remove the shafts(I figure that shouldn't hurt me for now, it's not a daily driver). I'm using Miller tool# MD998767 to set the pulley tension and have tried both the 5/32" drill bit between the auto-adjuster / tensioner arm method and the grenade pin slide-in/out method - belt tension seems perfect. Cam/Crank timing is right on, oil pump marker even lines up(just because).

The whine is heard from idle all throughout the rev range. I started removing accessory belts and components until it was eventually down to just the crank pulley with no front cover...it's definitely coming from the timing belt/component or oil pump area. I've pulled the belt and all components off and checked to make sure they weren't damaged and move/spin freely, and re-set my timing and tension a dozen times. I didn't run the engine very long before I changed everything out(the old T-belt had a few gouges in it) so I can't say for sure the whine was there before.

Anyone have any thoughts or suggestions on this?
 
Whats the history of the car/engine? It could be the oil pump. The old style gears had straight cut gears that whine more instead of the revised helical gears. Does it sound like a tranny going in reverse?
 
The car sat for 4-5 years until I picked it up a few months ago. All fluids drained before starting. It's a '95(early '95 I believe), the guy said it has Wiseco pistons and Eagle rods(don't they all say that?), and I don't see any casting marks/numbers on the pistons(63dT, arrows, etc), so he may not be lying.

It doesn't sound quite as loud as a transmission in reverse, but similar.
 
If you have the time and/or resources available, pull the front case and check the oil pump gears. Otherwise I wouldn't worry too much about it. If the whine changes in tone or decibel level, then I would worry.
 
I just might do that, I'll probably pull all of the timing components one more time tomorrow and redo it. It's almost inaudible at idle and quiets a little when warmed up.

One thing I noticed on these Dayco pulleys, the tensioner pulley doesn't have a polished finish like the original or the idler. Is it possible the slightly rough looking finish is causing some fiction/noise?

Thanks for the help.
 
When you tensioned the tensioner pulley, did you twist the pulley up or down?
 
I tensioned it counter-clockwise, with the two holes beneath the bolt facing down.
 
I think that's wrong. The 2 holes should be above the nut.
 
I always tensioned clockwise. Recently I did it counter by accident, and had a strange noise, and found out later that the tensioner pulley was rubbing on the motor mount. That is probably your issue.
 
Tension clockwise even on a 2g 7-bolt? I'll try it out and see what my pulley clearances looks like, pulling it all apart now.
 
1g's are tensioned clockwise. Tensioner rotates upwards
2g's are tensioned counter clockwise. Tensioner Rotates Downwards.

If you are hearing a whine come from the timing belt then there is a 100% chance that the tension is too tight.
 
Well I'm back from a full day of trying to diagnose this thing. I pulled it all apart and started from scratch, lubricated the tensioner arm, verified all of my timing components were still in good shape and were the right parts for my engine(and showed no signs of rubbing against anything), re-assembled and timed it 4-5 times with slightly different belt tension each time with no luck of curing the noise. I tried swapping in the original timing belt idler, adjuster and auto-tensioner; same noise pitch and level.

The last time(and where it's at now) I put the new timing components back on and set belt tension just a hair on the loose side, which turned out to be perfect - grenade pin slid in and out with very little resistance after spinning the engine 6 times and letting it sit for 20 minutes, 5/32" drill bit fit between the auto-adjuster and tensioner arm. Same noise and pitch each time. My belt tension can't be too tight, and I'm not seeing any signs of rubbing or contact on the belt or components. I'll probably just leave it like it is and drive it around for awhile to see if it quiets down.

Anyone heard of a Gates belt having an inherent whine to it? I read a few threads of others saying other brand belts having a similar whine.
 
Did it make this sound when you first bought it, or just after you worked on it? Was the head off or did you just peak into the spark plug holes to see the piston tops?

Is this the original 7 bolt? I would think if it is a 7 bolt you can rule out the oil pump, it was the 1GA's that had straight cut gears, correct?

Well I'm back from a full day of trying to diagnose this thing. I pulled it all apart and started from scratch, lubricated the tensioner arm, verified all of my timing components were still in good shape and were the right parts for my engine(and showed no signs of rubbing against anything), re-assembled and timed it 4-5 times with slightly different belt tension each time with no luck of curing the noise. I tried swapping in the original timing belt idler, adjuster and auto-tensioner; same noise pitch and level.

The last time(and where it's at now) I put the new timing components back on and set belt tension just a hair on the loose side, which turned out to be perfect - grenade pin slid in and out with very little resistance after spinning the engine 6 times and letting it sit for 20 minutes, 5/32" drill bit fit between the auto-adjuster and tensioner arm. Same noise and pitch each time. My belt tension can't be too tight, and I'm not seeing any signs of rubbing or contact on the belt or components. I'll probably just leave it like it is and drive it around for awhile to see if it quiets down.

Anyone heard of a Gates belt having an inherent whine to it? I read a few threads of others saying other brand belts having a similar whine.
 
I'm running all gates components as well. At first I was going to say no, but now that I think about it mine whines too. It is extremely faint though. I've never seen another 4g63 in person besides mine but I'm pretty sure its normal. A little whine on any belt driven device I've been in contact with seems pretty normal.
If it sounds like a Pete Jackson gear drive though I would be concerned. A video of how it sounds might be helpful.
 
If the belt is too tight, the oil pump will make noise....although I've heard aftermarket (Topline) pumps with helical gears that were louder than OEM pumps with straight-cut gears even when the belt is properly-tensioned.

Seems to me the way you can tell if it's the pump making noise by itself and not from the belt being too tight is if the noise goes away after idling for a bit. If the noise remains, it's possible the belt is too tight.
 
Did it make this sound when you first bought it, or just after you worked on it? Was the head off or did you just peak into the spark plug holes to see the piston tops?

Is this the original 7 bolt? I would think if it is a 7 bolt you can rule out the oil pump, it was the 1GA's that had straight cut gears, correct?

I didn't run it long enough to notice, probably just wasn't paying a whole lot of attention. The thing had been sitting for 5 years, I was mainly concerned with knocks and leaks. I just peeked into the spark plug holes to check out the pistons. I had spare 7-bolt and 6-bolt longblocks at the time that I could peek into and easily see casting marks. These are all flat, not a mark or casting visible. As far as I can tell, original 7-bolt.

If the belt is too tight, the oil pump will make noise....although I've heard aftermarket (Topline) pumps with helical gears that were louder than OEM pumps with straight-cut gears even when the belt is properly-tensioned.

Seems to me the way you can tell if it's the pump making noise by itself and not from the belt being too tight is if the noise goes away after idling for a bit. If the noise remains, it's possible the belt is too tight.

I drove it around and let it idle for a while, the noise did quiet down a little but it's still there. I don't think the belt is too tight. If anything, I'm borderline not comfortable with how loose it is now but I don't think it'll cause a problem. It won't fall off and there's not enough play in it to let a sprocket slip. I'll try to get a video up soon, right now I'm having some tuning issues.

Thanks for the responses :thumb:
 
If this is the blue kevlar gates belt I would say its normal to make a small amount of whine. I wouldn't worry about it to much if you adjusted the grenade pin correctly .

So did you do it correctly? :D You should have adjusted the tensioner so that the pin had a small amount of drag to it and then rotated the motor by hand a few full cycles and rechecked the pin to make sure it still had a small amount of drag before taking out the pin.
 
Have you tried a stethoscope to pinpoint the sound?

No stethoscope, but I did try a long screwdriver. Didn't work so well for me, but I'll borrow a steth from a coworker this week if I can.

If this is the blue kevlar gates belt I would say its normal to make a small amount of whine. I wouldn't worry about it to much if you adjusted the grenade pin correctly .

So did you do it correctly? :D You should have adjusted the tensioner so that the pin had a small amount of drag to it and then rotated the motor by hand a few full cycles and rechecked the pin to make sure it still had a small amount of drag before taking out the pin.

It's a normal Gates, not a blue kevlar. I am positive my belt tension was correct. This last time, the drill bit and grenade pin both moved in and out freely. All 30 other times, the pin would move in and out after spinning and sitting but had resistance.

After driving it around and letting it run for awhile, I've noticed what looks like belt residue rubbing off on the idler and tensioner pulleys. Maybe I just have a defective belt? I may just drive it around for another week before I spring for a set of OEM pulleys and another belt if this keeps up.
 
Wipe clean the residue off of the idler and tensioner pulleys and see if anything changes. A few years ago, I was told that this actually can cause a whine, but I've never personally confirmed that. The residue should go away as the lettering on the outside of the belt wears off.

My Gate's Racing belt (blue) does seem to have a bit of an inherent whine to it. But I don't know if that would carry over to the standard Gate's belt. And the whine is definitely not as bad as what your describing.

I wonder if a bad crank pulley could cause a whine? I've never heard of it, but who knows.
 
Yea I would think a crank pully could do it.
We used new OEM pullys and tensioner parts on my bros car with a blue kevlar timing/balance belt and got a small amount of whine which has since almost disappeared after 20k miles.

Maybe your balance belt is to tight?
 
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