Jump to content
  • Welcome To Mopar1973Man.Com

    We can see that your guest and been lurking about. When you register on the Mopar1973Man.Com site you'll be able to interact with all the other members. This is the most friendliest Cummins forum you'll ever join. Take the time right now and  REGISTER  on the Mopar1973Man.Com this will open up many more options and functions on the website. Everyone is very friendly and helpful just ask questions and everyone will help you out the best they can. 

Sign in to follow this  
Brubro67

High Pitched "Cricket" Buzz

Recommended Posts

Hello,

 

I have an odd buzz or hum coming from what appears to be under the driver's area hood which projects through the driver's side dash.  It sounds like a relatively loud high pitched cricket buzz.   It started under load, but sometimes continues (more often now) during constant throttle.  If I back off on the throttle, it most often stops.  It seems to be increasing in frequency but sometimes does it very little.  Since it happens only when driving, I can't pinpoint the issue.  It is definitely not loose metal, heat shields, exhaust, etc.  It seems electronic, tied to throttle response.  I've searched on line with no luck.

 

Any ideas?

Share this post


Link to post
Share on other sites

There are no error codes.  Injector pressure is fine per Ultragauge info.  Injector line hold downs are fine.  No fuel leaks, or other obvious problems.

 

I haven't tested lift pump pressure, but there is no delay in start (extended cranking) etc.

 

BTW, truck has about 160K, only mods are aftermarket exhaust that I know of.  There is nothing obviously modded other than that.  Link on testing fuel pressure?  I will do a search when I get home if you can't.  Thanks!

Share this post


Link to post
Share on other sites

Not that I can tell.  Runs great overall.  Had boost leak issue with '98.5 that I owned prior to this one.  That was obvious and I still have my homemade intercooler pressure tester.  Haven't bothered to test that since it runs so well.  No drop-off of performance at all.

 

It really sounds surprisingly like a loud cricket.  It happens when accelerating, and I can make it stop usually by backing off the throttle.  If I accelerate slowly, it usually doesn't happen.  Sometimes it is normal under moderate or heavy load too.  Truck is used  primarily for hauling 10K loads on average, but it also does this when unloaded.

Share this post


Link to post
Share on other sites

Power steering fluid is at level.  Dampener is in place.

 

Understand that all of this is reference to my view point, IE, the driver.  So, I understand that although it appears to me that it is coming from the driver's side, that may be a matter of perspective.  Wife thinks it is coming from drivers side too though, when in passenger seat.  It is one of those noises that is very hard to pinpoint.

 

Here are two wav files.  On "1" I was able to generate and capture the buzz.  That happened to be my first attempt.  I tried several times after to get a better audio recording, and the truck won't replicate.  This is my nightmare.  You can hear that it is tied to throttle response.  I didn't mention that it never happens in 3rd of overdrive.  It is always 1st and 2nd.  Once you are up to speed, if it happens (I can't recall), it is very rare.  It does not matter if it is warmed up or not.  There is no difference that I can tell with engine temp.

 

I completely rebuilt the tranny a little while ago with upgraded components such as billet torque converter, etc.  It was a mild upgrade, simply for reliability for hauling, not performance.  I don't need a race truck.  This made no difference or change with the noise, although the frequency of it occurring did seem to have increased slowly over time.  ...Or, I am more cognizant of it.

Cricket 1.wav

Cricket na.wav

 

I just listended to the files here.  You can hear it but not as obvious as on my phone.  Maybe use headphones?

Edited by Brubro67

Share this post


Link to post
Share on other sites

Turbo damage or has bearing play? bad Idler pulley?

Share this post


Link to post
Share on other sites

 I cannot get the file to play on either my phone or computer. 

 

If it only happens in first and second gear I would suspect one of two things. First it’s in the transmission, and second road noise masks it at greater speed’s.

 

Have you driven around locked in second gear and created a way to re-create it on demand?

Share this post


Link to post
Share on other sites
51 minutes ago, JAG1 said:

Turbo damage or has bearing play? bad Idler pulley?

Turbo is fine.  No play, rock solid.  I'll check idler pulley, but I don't see slop when engine is running.  Will check though.

28 minutes ago, AH64ID said:

 I cannot get the file to play on either my phone or computer. 

 

If it only happens in first and second gear I would suspect one of two things. First it’s in the transmission, and second road noise masks it at greater speed’s.

 

Have you driven around locked in second gear and created a way to re-create it on demand?

Strange; it is a wav file, works on both my computers.  Anyone else having this problem?  Can I email it to you or something?

 

I can't imagine that it is the transmission, not coming from that area at all.  It definitely sounds electronic.  Plus, it started before complete tranny rebuild by a very competent shop and didn't change at all afterwards.  It just slowly got more frequent in occurrence.

 

Road noise could be issue, but I am pretty aware of it and it just seems to be an issue under roughly 45 mph.

 

I can usually create it by putting engine under medium load, but it is sort of hit or miss.  It did it on the first attempt to record, and a few times after but recorder didn't capture properly; too much wind noise.  Then the truck just refused to do it on several more runs.  it is baffling.  If it was tranny, turbo, pulley, I can't imagine it would be that random, but what do I know.  All I can say is that this is the MO.  Drove it around an entire weekend and it hardly did it at all.  Monday morning, sort of non-stop until it got to speed.  No power issues, everything runs perfectly, all ultragauges, codes and alerts show everything is normal.  Sounds sort of like bad relay or other electrical component starting to fail, but I know there aren't relays on this vehicle.

Share this post


Link to post
Share on other sites

Take and squirt a shot of W-D40 at the idler pulley bearing. See if it goes away.

Share this post


Link to post
Share on other sites
47 minutes ago, JAG1 said:

Take and squirt a shot of W-D40 at the idler pulley bearing. See if it goes away.

Will do.  Worth a shot.  Thanks!

 

Doesn't sound like a pulley, but worth a try.  Bad pulley is usually more of a squeaky, sometimes clanky noise.

Edited by Brubro67

Share this post


Link to post
Share on other sites
28 minutes ago, AH64ID said:

Hopefully that does something, but the accessory drive has no clue about load, road speed, or what gear you’re in. 

That's my thinking too, but need to check them for play anyways. :thumb1:

Share this post


Link to post
Share on other sites

Been busy but here is either a development or coincidence:

 

When I checked the power steering fluid, mentioned by Mopar1973Man, it was about half way between full and add.  So, I topped it off.  Since then, it seems to be doing the cricket buzz less frequently.  I will do a full fluid exchange this weekend and see if it makes a difference.  The fluid does not look fresh, so it needs to be done anyways.

 

Has anyone heard of the hydro-boost making noises before other than what I consider the standard "hiss" which stops when the brake is applied?

Share this post


Link to post
Share on other sites

Feels good to back posting.  It's been way too long and I have been way too busy to be away from this great forum.

 

Anyway I helped my buddy @Brubro67 flush his power steering fluid today.  He came back and the noise was still there so I went for a ride with him.  The noise did come back but for a short time.  To me it sounded like a high pitched squeal like a belt slipping or a bearing.  When we got back the fluid was low probably from getting the rest of the air out of the system. Hopefully topping it off will take care of it. I wonder if there's anything in the hydroboost that could make a sound like that but I doubt it.

 

We agreed that he should take the belt off and check the power steering pump to see if the is any play in it or feel if a bearing is heading south.  He will also check all others pulleys to make sure they are good.  I'm glad it doesn't do it constantly because it was very annoying.  Hopefully he can narrow it down this week.

 

Glad to be back and hope stay.

L8tr

d

P.S.

@Mopar1973Man I hope you are feeling better

Share this post


Link to post
Share on other sites
31 minutes ago, Mopar1973Man said:

Fan belts can do weird things too if the belt is too worn between the ribs it can make random noises at different RPM's.

I'm pretty sure it's new.

 

L8tr

D

Share this post


Link to post
Share on other sites

The truck you have listed is a 4x4 right. It might sound far fetched but I have seen it before. The pinion bearing can make sounds like that and project up and sound like a belt or idler going bad. They usually act up when loaded and then quit when unloaded. Being that these trucks(at least from the ones I've delt with drive the front drive shaft all the time, when you accelerate it loads the pinion then when you let off it unloads and quits making noise. Check your diff fluid and play in the pinion could be a bad u-joint as well, but I have seen pinion bearing do crazy stuff on the big 4x4's I use to build. 

  • Like 1

Share this post


Link to post
Share on other sites

I had the squeal sound once. It was vague enough you couldn't tell where it was coming from and since that truck has to be ready for long distance travel I replaced the idler pulley wheel, the belt and the water pump . It was quiet again.

 

Later when I had more time I spun the used water pump with my hand and you could tell it had a rough spot to the bearing. It only had about 40,000 on it is all.

Share this post


Link to post
Share on other sites

Thanks all for the input.  After topping off the power steering fluid after full exchange, the noise continued that day here and there.  Then entire drive to work this AM (~30 min) it was absolutely quiet.  But, it returned on way back home.

 

I will check all the pulleys some time soon when I have a chance.  Really busy and very little time to work on truck this week.  Scout camping with the boy this weekend, so I doubt I will have a chance before Sunday PM, but I will try to check it out then.

 

Belt is new, replaced about 10K miles ago, just before transmission rebuild, when I had to replace the transmission heat exchange, which caused the failure.  Also replaced the fan clutch.  At that time, all bearings & pulleys were fine.  Doesn't mean that something didn't go since, so all of that is on the list.

 

Replaced the u-joints about two years ago with ones with zerks, all seem fine.

 

Noise is definitely load related IMO.  It will start, stop, then come back a few seconds later with throttle manipulation when it is in the mood.  The randomness leads me to think bearing, although I have never heard a bearing sound like that.  It definitely has a "reedy" quality to it, and it does not change pitch with RPM.  It also only occurs between 1200 - 2100 RPM, primarily in 2nd gear, but sometimes for a second after shifting in 3rd.  It never occurs in 1st or overdrive, no matter what load or RPM.  I am quite tuned into it now, and can say this with a high certainty.

 

I will post up the pulley & pinion results once completed.  Thank you all!

Share this post


Link to post
Share on other sites
55 minutes ago, Brubro67 said:

Noise is definitely load related IMO

 

56 minutes ago, Brubro67 said:

It definitely has a "reedy" quality to it, and it does not change pitch with RPM.

 

Don't rule out a boost leak.  I have heard boost leaks that have a reed sound (like in a musical instrument).  In two cases the cause was a broken hose clamp and the reed-like sound was coming from the vibrating hose end under certain boost conditions. 

 

Some of the symptoms you have described could match that of a boost leak.

 

- John

  • Like 1

Share this post


Link to post
Share on other sites

On Friday, I finally had a chance to look into the pulleys.  The power steering pulley has a little play.  I suspect thats the culprit.

 

So, do I replace the entire unit since it has 166k miles or just the pulley?  I'm leaning towards replacing the entire unit unless there is general consensus that there is lots of life left in the unit; ie, 166k miles is just broken in for them.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  



×
×
  • Create New...