Cruise Control noise

[PKearny]

I noticed that several threads exist from last year reference this subject. My 04 2500 2WD QC exhibits the same behavior when C/C is engaged. Sounds as if source is behind the glove box. It could be in the engine compartment on the passenger side however. Any updates/discoveries here? Thx mucho.

 

[Brian-NX9O]

Is your truck automatic or manual transmission?

 

[PKearny]

My Bad. My truck is equipped with the 48RE





THX

Pat Kearny

 

[Brian-NX9O]

On my '03 w/47RE and probably on the '04 w/48RE there is a small vacuum pump mounted on the passenger side upper fender-well between the battery and the firewall. This is a small pump that is required for the automatics with cruise control. My pump was cycling almost all the time shortly after I took delivery of the truck. The dealer replaced the pump and some of the vacuum plumbing. It would cycle even when stopped at a light with cruise on but not engaged. I can send you photos of the pump on my '03 if you are interested.

 

[PKearny]

BRIAN: Thx for the quick reply. We are in midst of major T-Storm now but I will locate pump in morning. I have not tried seeing if noise exists stopped with cruise on. I'll try that in AM also. Did dealer balk at replacemant at all? " That's normal etc??"



THX Again,



Pat Kearny

 

[Brian-NX9O]

The dealer was great about it. I took it to them for a couple of things including the noise. I told them I was not sure about it as it was not that noisy, but it was cycling quite frequently and was different than the noises of truck when it was brand new. I think it happened at about 1000 miles. I have nearly 19K on it now and there has been no return of the problem.



On the other hand, I am not sure what kind of reception I will get when I finally take it to a local dealer. The truck was purchased in Oregon from a dealer with significant inventory and experience with diesels. Suburban Atlanta is a different world.

 

[PKearny]

I located the subject pump on the passenger side fender well. It does not cycle while idling with cruise on/not engaged. It is certainly audible under certain cruise control conditions. Should the normal operation of this pump not be heard from inside the cab? Should a demo ride with dealer personnel result in pump replacement?



Thx again,

Pat Kearny

 

[JARichard]

Pkearnry,

Try the jack under neath the passengers seat. i thought I had a problem in the dash took it all apart and it was the JACK after 2 hours of disassembly and reassembly noise was still there. See thread New Rattle.

 

[Brian-NX9O]

I'm not sure if a demo ride would cause them to replace it or not. Noises are often a subjective thing.



The only time I really noticed the vacuum pump running is when when it had a leak in the system and it ran most of the time. The first time I noticed the pump noise during the leaking problem was after exiting the interstate onto a short nearly straight offramp with a long traffic light wait. I could hear the pump cycling while stopped at that light in Drive with the cruise on but disengaged. The radio was off and the kids had fallen asleep, so it was really quiet at that moment. Since that repair, I don't recall hearing it.



This last winter, I moved the vacuum pump to make room for the Espar coolant heater. I noticed that the pump is mounted on its own plate with rubber spacers/standoffs attaching it to the plate that is attached to the fenderwell. I guess if one of those rubber standoffs is dislocated it could make the pump much louder. The place I moved it to is even less likely to have any kind of resonance or noise transission into the passenger area. It might be that your pump is just out of its correct position and the noise is being conducted more directly. If so, it is a simple fix.

 

[JGoodwin]

its the vacuum pump on the right hand fender. needs to be replaced

Originally posted by PKearny

I noticed that several threads exist from last year reference this subject. My 04 2500 2WD QC exhibits the same behavior when C/C is engaged. Sounds as if source is behind the glove box. It could be in the engine compartment on the passenger side however. Any updates/discoveries here? Thx mucho.