engine noise 2005 mack granite

[Rwb]

Does it do it with cruise control on? And power should be 25% more with cruise on.if it does its in the ecm not injectors.you say its quieter when load is lightened up but if it stays quiet pulling or not with cruise on id look at the throttle positioner control on the foot feed. A heavy spraying with contac cleaner and working pedal might help try that a few times.might be defective.but

 

[sonoma]

I remember back in about 2001 a couple drivers had a loud noise in their radios we had a hard time finding. they said it would change depending on the road type they were on. finally found out it was the belts in the tires. . when they were setting still the noise was fine. a couple of the trucks we put powdered graphite in with the oil in the hubs and that even helped. after one driver changed his front tires and the noise went away was how we found it to be the belts in the tires.
so good luck on this one.

 

[Tallman]

 

[Jammer463]

Does it do it with cruise control on? And power should be 25% more with cruise on.if it does its in the ecm not injectors.you say its quieter when load is lightened up but if it stays quiet pulling or not with cruise on id look at the throttle positioner control on the foot feed. A heavy spraying with contac cleaner and working pedal might help try that a few times.might be defective.but

Yes even with the cruise control on it still does it when you're under load

 

[Low_Boy]

Had a 2007 Mack last year no problem. 2012 Pete. (Junk) this year and wine when headlights are on. Infact was in the Mack this week and no problem at all

 

[543_Dallas]

I know this is a old post but has anyone had any luck?? I just started driving a 2005 Mack granite e7 350 and I'm dealing with the same problem, the receive on my radio gets incredibly loud it even changes tone when the engine is under load, it's fine when it idles, I even tried a inline low pass filter ,nothing!
Any help would be appreciated

A 2005 with an e7? I figured it would have a rebranded volvo engine in it.

It's odd that it does it under load only. So you're saying that at full throttle in neutral no noise but under load only? If that's the case I wouldn't think it would be injector noise. That would vary with engine rpm regardless of engine speed.

Does the noise get louder as the turbo spools up? If this is not actually an e7 and one of the MP engines they have variable geometry turbos with a speed sensor. I wonder if this could be the source of the noise. Turbo speed is proportional to engine load but not so much engine speed.

There's probably not a lot that can be done if nothing is actually wrong with the engine. I would recommend that you double check your antenna installation. If the mount is not making a good connection to the body you may have a common mode current issue. Most people think cmc when they are bleeding on their stereo speakers or something else but it works both ways. Id be curious to see if a coax choke or stack of ferrite around the coax at the antenna feedpoint makes a difference.

The main thing is to make sure the antenna mount makes a good connection to the mirror and the mirror is bonded to the door. It's been a while and I don't remember how much of those trucks are made of fiberglass. I do remember guys with the better radios used a perch mount on the volvos. You removed one of the mirror bolts and replaced it with a large stud that the antenna mount would clamp on.

 

[Rwb]

Yes even with the cruise control on it still does it when you're under load

sounds like in ecm.a circut tells more fuel n it opens . Unless engine to frame isnt grounded proper engine torques up n might not ground proper or a wire is moving somewherebin the harnesses n has a wore spot making a scratchy ground

 

[OldTech03]

When I was tracking down noise I used a walkie-talkie that I modified like a Frankenstein walkie talkie but it was really good at tracking down the source of the noise. I modified it with handheld loop much like the near-field loops I use with my frequency counter and spectrum analyzer. The trick is to make the loop very small as to make sure it is shielded right up to the very edge of where the loop begins using a good grade shielded cable that is then attached to a length of fiberglass rod from an old fiberglass antenna it was about 2 ft long, long enough to reach almost everywhere I needed it to. Since most walkie-talkies don't have an RF gain control I modified the talkie to have one and also used a small meter off a field strength meter and wired it as an ac voltmeter across the extension speaker output because I always used a headset with it so as not to have any outside noise when using it. Now, this may all sound crazy but it worked for all kinds of tracking down of noise and helped me locate a lot of issues both in Trucks, cars, and homes. It made pretty short work of locating the source. Now once the source was found it was not always a simple matter of eliminating the issue that's where experimenting comes in and there were plenty of times when I was ready to call it a day. I just acquired an old TRC-207 and plan to make a noise tracker out of it as well.
As for the noise you are having it is imperative that you first figure out what it is I know that sounds like an "Oh you think maybe" statement but it saves a lot of time and money usually. But on the bright side, everything you did so far has not made it worse. And I also realize what I did with the talkie may not be in your wheelhouse but it may be something someone you know can put together for you.

 

[nomadradio]

Worst noise from a passenger vehicle is often the electric fuel pump. Not so much from the brushes, but from the contact points in the centrifugal-control mechanical speed regulator. That particular noise will change with fuel demand, from idle to cruise speed. Some fuel pumps will start when the key is first turned on then stop once fuel pressure is present, and restart when the engine is running. Others will just run as soon as the key is turned, without shutting off at all.

Don't know about big trucks.

73

 

[Rwb]

Big trucks have mechanical pumps but new engines must have an ecm to direct the fuel and control the rate for power request.and every electrical componet has ties to the ecm making more fun to track down. As simple as a broke,bare scraped wire to partial connected plug to major componets.
12.7 detriot i drove never had full power .it made a nasty whine on cb.1 day she went dead.it went to a truck repair shop.turned out where the ecm connectors plug into ecm 1 pin was never soldered.they cleaned it n soldered it .ran fine no noise on cb and power was up.they bought the truck cheep low miles n figured that was why

 

[Low_Boy]

Possibly the difference is the truck I have had no problems with has a big, and do not remember the size Cummings in it.