# Guess that noise!



## iedgar10 (Sep 25, 2014)

About a week ago i noticed a buzzing/clicking noise under the hood. It has gotten progressively worse as before I would only notice it when I remote start and then unlocked the car. Now it sometimes does it when idling. I have noticed it mostly does it when I use something electric. Whether it be the remote to unlock or when turning the steering when when idling. Yesterday, it did it while just parked with the key and and engine on. 

Here is a link to a video. You can hear it throughout but it's louder starting at 8 seconds. 
any ideas? it doesn't seem to affect performance at all, it's just getting progressively louder and more constant.


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## brian v (Dec 25, 2011)

Hey Gùys we have a new Game to Play ! Great idea .. Guess that Noise !


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## NickD (Dec 10, 2011)

Sound travels seven time faster through metal than air, won't even begin to guess, but with problems like this, get out my stethoscope. 

By any chance, and just a wild guess, is your tensioner pulley jumping around when that noise is present?


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## iedgar10 (Sep 25, 2014)

Nickd, I tried checking it after work today but the darn thing wouldn't make the noise no matter what! And yesterday it did it almost constantly...


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## NickD (Dec 10, 2011)

Check engine light off? At idle, tach running smooth? Being there makes a huge difference. was riding in the back seat of my kids car, started making weird noises, said you have water in your gas. Run smooth for awhile, then misfire. An example of an erratic problem. Stop at a gas station and put a can of Seafoam in the tank, helped a little, but cleared up.

Can be some weird stuff, loose piece of sheet metal someplace, recall a loose bell housing bolt, also quite erratic, can vary also with temperature. Is the fan coming on?


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## iedgar10 (Sep 25, 2014)

NickD,

I think you hit the nail on the head. 
More details: 
-no CEL 
-noise comes on randomly either when remote started, AC running, or power steering is used 

Today the car was making the noise while parked and AC was running so I quickly whipped out my phone but wasn't able to get a video before it stopped. But I took a picture and i circled the area where the noise came from. I circled the pulley where the noise came from. 
I don't believe this is covered by powertrain, so how urgent do you think it is to get this replaced?


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## jblackburn (Apr 14, 2012)

Try not using the AC or leaving climate control on for a day and still see if it happens. 

The ac compressors are known to make a whining noise after shut off - supposedly there is a software update to alleviate the issue.


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## iedgar10 (Sep 25, 2014)

I'm not so sure if it could be the AC since the noise is produced even with the AC off. It does it sometimes with remote start and neither the power steering or AC are being used.


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## ChevyGuy (Dec 13, 2014)

iedgar10 said:


> I'm not so sure if it could be the AC since the noise is produced even with the AC off. It does it sometimes with remote start and neither the power steering or AC are being used.


Keep in mind that on many cars A/C will kick on on defrost or if the system wants to dehumidify.

What's the history of the water pump on this car? I wonder if it's early indication that it's gong. (Since it seems to be a common failure item on the Cruze.)


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## iedgar10 (Sep 25, 2014)

The AC was not used today and I heard it only once for a few moments at a red light. I'll drive it for a little longer than my regular commute tomorrow to see if extended driving makes it worse.


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## NickD (Dec 10, 2011)

New tension pulley runs around 33 bucks, can be tested with a torque wrench, should work smooth with around 100 ft lbs of torque.










But can be either the culprit or the victim, harmonic balance, AC compressor, alternator, and the water pump that is all that is driven. Can say goodbye to the power steering pump on the Cruze, all electric.

Radiators have been a problem since day one, going back more than a hundred years on this, they are bug collectors. Compounded by adding a condenser in front of it with a side effect of an overheating engine. Cussing out my Cruze in this respect, worse vehicle I have ever owned to access the condenser, have to clean it from underneath. 

With restricted airflow, compressor pressures skyrocket on the high side putting a lot more strain on the drive belt that can be reflected in the tensioner pulley. Can also be a poor bearing the compressor idler pulley or any other pulley in these crazy single belt drive systems. Most important is keeping the water pump running. A ton of engine heads have cracked ever since they came out with this BS. But hey, you only have one belt to change. Only AH's make this statement. 

Then making limited lubricated ball bearing in China, but feel over the years, doing a bit better. Nobody made better ball bearing than the US and going back over 75 years on this subject. One pulley goes bad and you are stranded, not a good idea, never was, and never will be. 

Insect buildup problems on the condenser were never solved. On other vehicles installed a fiberglass screen angled downward, easy to brush off where the larger bugs fall off. Also prevents a stone from knocking a hole in your condenser, $$$$ when this happens, in particular with R-134a. Entire system has to be flushed to do it right. And doing it right is rare nowadays.

Ha, you got me started.


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## iedgar10 (Sep 25, 2014)

NickD said:


> New tension pulley runs around 33 bucks, can be tested with a torque wrench, should work smooth with around 100 ft lbs of torque.
> 
> 
> 
> ...


NickD,

My friend, you are a genius! You took the dive and won this game of "guess that noise." 
Today I took my car for a 30 min highway drive and the darn noise would not come on. Came home, parked, and started turning my wheel. I could hear the darn noise but since I was turning the wheel I couldn't follow it. Some of the guys here mentioned the AC so i turned the AC on and sure enough, as soon as the compressor kicked in the noise started. Before I turned on the AC the tension pulley was nice stiff and silent. Then, with AC on, the tension pulley started jumping around and I could feel feel the noise going through the spring whenever I touched it. 

Here is a video for anyone else having this issue:




My local shop quoted me $110 +tax to get it replaced. I thought it was fairly reasonable so I made an appointment for this Saturday. Do you guys suggest getting anything else replaced while they're in there replacing the tension pulley?


Edit: the only odd thing that I can't understand is why it doesn't always do it. If the bearing is bad then wouldn't it always make the noise? I went back to the car for a second look and the pulley was bouncing more and no noise... Had to turn the AC on and off multiple times for it make the noise... But it was much more subtle


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## NickD (Dec 10, 2011)

Would also Look some R-134a gauges to the AC ports and take a look at those pressures.

What does your condenser look like, can you see light through it. Just in case you don't know what it is, is that thingy in front front of the radiator. Can view it through the front grille with a trouble light.


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## Chevy Customer Care (Oct 29, 2011)

We're interested to see how this plays out, iedgar. Definitely keep us updated and as always, we're here to offer additional assistance as necessary.

Talk to you soon!

Amber N.
Chevrolet Customer Care


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## iedgar10 (Sep 25, 2014)

NickD, 

That's something additional to lookout for, right? Not related to the tensioner? Why do you think the tension pulley only makes the noise sometimes? 

I also asked the shop to get me an oem AC Delco belt to go ahead and replace it since the labor change would not change. They said they'll do both in 30 minutes this Saturday morning. I'm excited to finally have my car 100%. I feel like I can't trust it with all the little things that have been going wrong with it. My girlfriend has been insisting I trade it in but since I still owe money on it I don't think it's such a good idea. Maybe I'm just at that 50k point where there is a lot of maintenance due.


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## iedgar10 (Sep 25, 2014)

Thanks, Chevy customer care. I'll definitely report back to confirm the fix worked for all future browsers that stumble upon my video and have the same issue.


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## NickD (Dec 10, 2011)

iedgar10 said:


> NickD,
> 
> That's something additional to lookout for, right? Not related to the tensioner? Why do you think the tension pulley only makes the noise sometimes?


Not thinking, but knowing, single drive belt systems have been around for about 30 years now. Like a rope in series with a spring tied between two tree. Hang an excessive load on that rope can exceed the force on that spring, it will stretch as will the tensioner spring. Compressor loads are not constant, more like pulse loads, but not put stress on the tensioner, but any other sheave in the system as well.

Excessive loads caused by either the compressor or the alternator can also damage the water pump bearings causing leaks. So with water pump problems, may not be the water pump, but its the victim of other devices in the system causing excessive loads on the series system. And replacing the water pump is not the solution, the new water pump will see the same stresses.

Very common knowledge in the engineering field dating back more than a couple of hundred years. This is why all vehicles were using multiple drive belts. Heck my 1973 Fleetwood had five belts, P-30 has three and so does my 88 Supra, to isolate these loads, but all common to the harmonic balancer drive source. 

So why did they develop the single drive belt system? Only one reason, its cheaper. But if that one belt breaks, kills the entire system. Did have a bearing seize up on my idler driving the compressor that only broke its own belt. Still had the alternator, fan, and water pump working just fine. Just lost AC, but still could keep on driving. 

But if that belt breaks in a single drive system, you are screwed to the wall, very stupid idea. You can be stranded in ice cold conditions and die because of this. And some have. 

The tensioner can be tested for smooth operation with a torque wrench in two seconds, yet another problem is it pulley with a limited lubricated ball bearing that can seize. This can be replaced separately for ten bucks. 

Do you want to learn more stupid changes? Going to hear them anyway, the switch from R-12 to R-134a that was never proven to deplete the ozone layer. Automotive use of R-12 was less than 2% of the entire CFC production, rest was used for worthless stuff. The difference? R-12 pressures increase at a linear rate with temperature whereas R-134a increases at an exponential pressure rate with temperature. A plugged condenser causes extremely high pressures that put severe loads on this single drive belt system. And really augmented by ambient temperatures as well. 

Can be a key reason why your tensioner is jumping. Another stupid change is on the harmonic balancer the drive pulley. Some instead of using a solid pulley elected to split that pulley separated by a piece of rubber. Their reason, to cut engine noise by one db or so. But that rubber hardens, breaks, so while the inner section is spinning, the outer remains stationary.

All the ball bearings in the driven components can be replaced, GM made this extra difficult by using an interference fit on the compressor idler pulley to save a 2 cent retainer ring. So far, four different special tools are needed over the years, can't even use the same tool. Then that pulley can shift causing gap changes of either the clutch is burning up by rubbing or has excessive gap so it won't even energize. Stupid, shims were used for years.

Water pump always has been a throwaway item, can't lubricate it, just a bronze bearing with an inner seal on it. Could have made this part separate so that is all that had to be replaced.

So if you are wondering why we are having problems, this is some of the reason, always a reason. And if the idiot cannot determine the cause of the problem, just throwing parts at it costing you a small fortune. 

Ha, you got me started again.


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## iedgar10 (Sep 25, 2014)

UPDATE:

I got my tensioner and serp belt replaced this morning. $140 with parts and labor included 4000 mile/90day warranty. The noise is completely gone. As per NickDs recommendation I asked the techs to take a look at the compressor and to check other components on the belt drive. They said all looked good so hopefully the tension pulley just died and nothing else is wrong. I'll revive the thread if the noise comes back!


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## money_man (Feb 25, 2014)

Good to hear. Pretty common issue really. Not with the cruze but just vehicles in general


Sent from the sexy electrician


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## NickD (Dec 10, 2011)

How is this for a belt routing diagram?









5 is the tensioner, 8 an idler, 2 the water pump on a 98 Ford ZX2, a FWD 4 cylinder jammed to the sidewall with only about an inch of clearance to work on.

This one used the clock spring type tension, no under engine cover where road salt could splash causing causing severe corrosion so the tensioner was partially seized. That snapping action took out the water pump bearing so that had to be replaced, two studs broke off holding the pump. Started this job at 8:00AM on a Saturday morning, was done at midnight.

A main attraction for me buying the Cruze, did have a under engine cover, then they wanted to butcher it. That linear spring on the Cruze is new to me so really don't have an experience with it. But does seem it needs some form of lubrication. at least to retard corrosion.

At our airport on an aircraft engine, doesn't have all this extra crap like the AC compressor, power steering pump, and water pump, air cooled. So the alternator was gear driven from the engine. A two buck bearing in the alternator seized that caused his crankcase to crack. Maybe not a good idea either to get rid of that belt, his repair bill was $40,000.00.


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