kennyy

hey guys i recently had a problem with my Z making a chirping/cricket noise, so i went ahead and replaced both belts to OEM nissan. When i started up the car i had no noise so i figured it was fixed, but i drove it around and when i came back home the noise came back when it idled.

Usually the noise happens when I come to a stop, the noise will go away if i rev the engine.

the tension on the belts should be good, i followed the specs on the thread on here with 5mm deflection on the bigger belt and about 10mm deflection on the thinner belt.

Although usually these type of noises come from the belt i felt like when i popped the hood it was coming from the back of the engine (towards the firewall) but i could be wrong, the old belts were pretty trashed though.

Anyone have an idea of what it could be?

StreetStandard

Did you check all the pulleys to make sure they were not going out?

The_Assassin

I have been hearing a similar sound. It only happens when its cold or when I haven't turned on the car in a long time. It doesn't stay on though only on startup.

guitman32

iTrader: (15)

Belt pulley bearing or something with the AC clutch. I am having a similar sound on my G35 that I haven't had time to chase down.

I had a similar issue on my truck also, which resulted in a pulley exploding. Don't want to let it go for too long.

kennyy

Thanks for the reply guys.

If it's the pulleys would it be normal that changing the belts made the noise dissapear until I drove it for a few miles?

kennyy

How exactly can I check if the pulleys are bad? Is the only way to check it by using a stethoscope? Or can I hear any sounds by just removing the belts and using my fingers to spin the pulley?

Jennifer 2

Kenny, if you look at an online copy of the factory service manual you will see that Nissan provides two different tension specs. One is for tensioning an existing belt that has been in service for sometime, and another tighter one for installing new belts on pulleys that have some miles on them. What you are experiencing is quite common. The groves on the new belt wear into and seat a little deeper into the pulley groves. This is an expected ‘break in’ process for the new belts and they need to be retightened as they have lost some of the tension you set them at.

I can’t remember the exact method we used when setting the belts on my car, but it entailed pushing a set amount of force to the top of the belt run and then measuring the amount of deflection. I can look it up if you if are unable to find it.

First check out the longer of the two belts as that one is most likely to chirp /squeal as it is driving more accessories.

kennyy

Thanks for the reply Jennifer, i noticed that my belt only squeals when i turn the wheel so I'm assuming either the belt is a little loose or the pulley for the power steering is bad. Would you happen to know which bearing I need to buy? i might as well replace both but I'm not sure on what exactly i need to buy

Jennifer 2

Kenny, when you hear hoof beats, think horses, not zebras. Even the mechanics here (which I’m not one of) cannot fix your car over the net; they can only give you a list of the most probable things to check first. If you hear some squealing sound in addition to the sound of crickets (especially with the first cold start of the day) it would indicate the new belt has lost some tension and needs a second tightening. If there is no hint of belt slip/squeal then check the bearing in the idler pulley (on the top of the larger belt) for roughness and excessive side play. My bet is on simple belt slip though.

kennyy

hey guys sorry to bring up an old-ish thread but i ended up tightening my belts and the noise is still there, and once again only when i rev past 1000k rpm the noise goes away. Im guessing its my pulley bearings, can anyone link me a site of which part it is, or a part number for the pulleys

thanks!

guitman32

iTrader: (15)

You have to find out which one it is first. Either use a mechanics stethoscope to isolate the noise or you can just remove your belts and inspect each pulley individually. The culprit will will probably be obvious (roughness and excessive axial play) but as i said it may also be your ac clutch. If the noise changes or goes away with the ac compressor engaged then it may be worth investigating, but that sometimes happens when a pulley fails anyway so isolating 100% can be tricky.

kennyy

I plan on changing both regardless to avoid the problem happening again

350zmark

I just started hearing the cricket noise the other day on my 2003 350z. The noise is there on start up but goes away after about 3 to 5 mikes of driving. I put on new belts in the spring so I'm going follow Jennifer 2's advice and check the belt tension. I will post the results.

350zmark

After completing the oil change task I inspected the belts and pulleys. I found the 14mm nut that secures the main idler pulley assembly was loose. I adjusted then tightened both idler pulley assemblies chirping sound is gone.

350zmark

The chirping noise came back. I was able to trace it the ac idler pulley. With the car running I was able to adjust the tension until the noise went away. In my case the belt was too tight.

dkmura

iTrader: (64)

That's an excellent point! Overtightening a belt will also cause problems and is almost as bad as not tightening it enough. Using the FSM method of checking belt deflection is a good way to ensure you're getting it just right.

Joe clan

Water pump failing. Had it happen on my 2009 jeep wrangle when it was only 2 years old. It's a chirp sound that happens every few seconds or so. Kept taking it to the dealer and they kept trying other things, when I told them it was coming from the water pump. Finally they gave in and just replaced the water pump after I botched for about 3 months. Guess what I was right never made the noise again and the mechanic said they were sorry they didn't listen to me sooner. Even the GM of the dealership apologized. He asked my how I knew it was the water pump. Told him it took screw driver and stuck it up to my ear and touched the other end of the screw driver to parts of the motor till I could here the sound. I was F***ING pissed that it took them that long to do what I told them to do.