When exiting the freeway and braking down ob the off ramp I hear a low sort of groaning noise that abruptly stops. kinda sounds like a valve shutting or solenoid shutting off. Everything else is normal, doesn't seem to be any malfunction. Just wondering if anyone else hears this or knows what is is.

Is it only when braking or does it happen also when you are driving and abruptly let off the go pedal?

Do a search for "drone" problem. That might be it. I think it happens around 1800 rpm, around 55 - 60 mph, about exit speed. There is a fix for it.

Mine does the exact same thing, sumtimes mine does it while turning, sounds like a power steering pump on mine, but it doesn't make sense while braking

I don 't think it's the "drone" problem.

I'll pay more attention, but I think it makes the sound with or w/o the brakes. I don ;t believe it's a malfunction of any kind, I'm more curious about what is causing it.

Heard that, i paid way to much money for stuff to be *****in up

I noticed the exact same sound on my truck today. It seemed to only happen when I let off the throttle from a cruising speed and immediately got on the brakes. When I let off the throttle and coasted before applying the brakes, it only did it once or twice. It sounded like the engine fan kicking on (or a steering pump under full load) for about 1 or 2 seconds then it stops. Could it possibly be the tranny making noises until the convertor unlocks? 650 miles on my new truck and now this crap... Censored

Yeah, it kinda does sound like a power steering pump under load. (I'm pretty sure it's not the P/S pump but it does make that kind of sound). The sound abruptly ends as if a valve or solenoid is shutting and I only notice it after driving at cruising speeds (freeway) and then abruptly letting off the throttle and braking (off ramp).

Again, I don't think it's a malfunctiuon (hoping), but I would like to know what it is! :think:

Is your truck an LLY?


The sound you are describing to me sounds like the VVT shutting down when you lift off the pedal?? My LLY does it but not my LB7.

Mine does the same exact thing. It is the torque coverter unlocking, and, according to my diesel technician is normal. I have driven several 05's that do the same exact thing.

Mine does the exact same thing, sumtimes mine does it while turning, sounds like a power steering pump on mine, but it doesn't make sense while braking

Actually, I believe the brake system hydraulic booster is powered (for lack of better term) by the power steering pump. If that is the case, then it can make sense. Hopefully some of the more knowledgeable folks will jump in and provide the details.

Mine did it and I took it to the dealer and they said there was a valve that needed to be upgraded they did it and now I have no noise at all.Give it a try,Mark

My '05 does not have the drone but it does do this usually after a highway run. I THINK it is a hydraboost/steering noise. I'll be calling my service writer on Monday about a possible valve replacement.

Thanks racecar.hotshoe!

My '05 does not have the drone but it does do this usually after a highway run. I THINK it is a hydraboost/steering noise. I'll be calling my service writer on Monday about a possible valve replacement.

Thanks racecar.hotshoe!
Thats when mine did it and when pulling my boat,It got real loud when I put on the breaks,I would have them replace the valve in the P/S...Mark

Please let me know what the service writer says. Mine does it too.

Hey, thanks for the replies. This is what makes this site so great - everybody getting involved and helping out!:ro)

Anybody that goes to the stealer please post here and let us know what they say. It sounds as if this noise is a common occurance, at least with the LLY's. If there is actually a problem I know we would all like to know!

i have the same noise but only when im towing

Well this is gonna sound really weird, but the other day when my truck was making the noise, my wife and I had decided to take a day trip up to Yosemite. Now that I'm back down in the valley, I haven't been able to make my truck duplicate the noise. I'm stumped, so I'll be watching this thread closely if anyone figures the problem out. Oh yeah, here's 2 cool pics from the trip:

The drone is a hydraullic boost to the brake system when there is a low presure condition, such as when you have been on the highway for an hour and not touched the brakes.

i have the same noise but only when im towing

Same here. Just like skeetdiesel said, it seems like it's only after I've been on the highway for a couple hours, and hit the brakes on an exit ramp.

Is there a TSB on this? I've got 11,000 miles on my rig.

The drone is a hydraullic boost to the brake system when there is a low presure condition, such as when you have been on the highway for an hour and not touched the brakes.

Well, this would not explain my situation. My truck was doing it on winding mountain roads. No way I could go for an hour without using the brakes...

I would have guessed torque converter. Mine does it in towhaul, right as it's making the shift down to first at a stoplight. Without towhaul it does it much sooner in a higher gear.

mine has done this for over a year it seems like something is binding at about 1300rpm or rubbing they changed my steering pump and no help my powersteering sucks nuts also

Well talked on the phone to my service "consultant" at James Wood in Denton where I bought the truck almost a month ago. Explained to him it sounds like the hydraboost is vibrating/buzzing at low rpm's, most obvious when slowing down from a highway run. He talked like it was not a common occurence and to make sure I could duplicate the noice so a tech could hear it. It's such a pita to go to the dealership I think I'll wait till it gets worse before I take it in.

This issue and the start/stop clunk because of dry driveshaft/yoke splines are the only complaints I got. To tell you the truth I expected much worse.

I can freeze my passenger out until they beg for mercy even at 98 degree temps, jerk my boat around like its some kind of kids toy, and get 16-17mpg in bumper to bump traffic. What else could I ask for, I love this thing!

Hey guys, take a look at the THREAD (http://dieselplace.com/forum/showthread.php?t=38342) that I started today about what appears to be the same problem that you are talking about!!! I didn't find this thread until after I started my own. Sounds like we are talking about the same problem though. What valve in the power steering unit did they actually change so that I can mention it to my service guys? How many of you had this valve changed out and did it cure the problem? This noise sure is annoying and doesn't seem to be a "normal operating noise". Any input will be gretly appreciated!

Wasted Income- what is a "TSB"?

Same here, but my GM dealer says it's normal, even though they can't explain it. my truck seems to do it more when in Tow/haul mode.

Same here, but my GM dealer says it's normal, even though they can't explain it. my truck seems to do it more when in Tow/haul mode.

Well this is gonna sound really weird, but the other day when my truck was making the noise, my wife and I had decided to take a day trip up to Yosemite. Now that I'm back down in the valley, I haven't been able to make my truck duplicate the noise. I'm stumped, so I'll be watching this thread closely if anyone figures the problem out. Oh yeah, here's 2 cool pics from the trip:

I live about 10 miles up the road from Lilwes in the Central Valley of California. I have about 5,000 miles on my truck. I drove it up into the Sierra's to the 7,000 ft elevation level. I also heard the groaning sound from the power steering pump at the elevation. Never heard it before, and haven't heard it since. Could elevation be a key here?

I don't think elevation has much to do with it, becuase I live at 2400 feet in Las Vegas, and took my truck on a trip to Colorado going over 12000 foot passes with the same proglem. But I do buy into the thought that it is worse when on the freeway for a long time, thus increasing the power steering fluid temperature, then when you stop, the fluid is hot. Don't know why hot fluid makes th PS unit whine, but that's my thought.

To dispel the LLY only idea, my '03 LB7 makes this exact 'droaning' noise. Has happened twice to me. Both times the truck was loaded with my camper and only occurred after being on the freeway for an hour or so while coming to a stop on the off-ramp (last shift before first gear -- both time in tow-haul mode also). I'm curious also as to the fix, since I don't think I could duplicate this w/o taking a GM tech camping with my family for a weekend!

Wasted Income- what is a "TSB"?

Tech Service Bulletin.

I live about 10 miles up the road from Lilwes in the Central Valley of California.

Well hello neighbor! :welcome:

I stopped by the stealer and told him about this today. Truck is going in for the 1,000 mile service (which the service desk guy gave me crap about), and to see if they can figure this noise out. I'll be taking some of these complaints and ideas with me to show him. If he finds anything, I'll report back.

lilwes278, please let us know what they come up with, or the lack thereof. I want to know the fix for this. Keep us posted. Thanks!

Well, just as I suspected, could not get the truck to duplicate the noise. Although the mechanic told me that they have changed out several of the faulty valves in the hydraboost systems (he's kinda the D-max specialist at this dealer). I told him of this forum, and that several others had the same issue. He was VERY interested and asked that I print off this thread and bring it to him. Told me that if my truck ever starts making this sound again, stop by and he will drop whatever he is doing and go for a ride with me to check it out. He also wanted to know more about the overheating issue. Extremely nice guy, so I'm hoping I can work with him to get some more info/ideas for a solution.

I've had the same senerio. After 30 min. + of towing and using the brakes, I get the noise. Strange that I don't get it unless I have been towing. It might be the amount of demand that is put on the system... i.e. if it has leaked down. Seems worse in tow/haul as it downshifts too.

This may not be related but mine was making a noise during deceleration/braking. I took it to the dealer twice and on the second time took the mechanic for a ride to hear it the way I did. He felt something under the floor board and checked the dealer installed, described on the window sticker as 'Chrome Tubular Assist Steps'. Turnes out they were rubbing the frame someplace. I don't know what he did to them but it stopped the noise. Maybe this will help some of you guys...

This may not be related but mine was making a noise during deceleration/braking. I took it to the dealer twice and on the second time took the mechanic for a ride to hear it the way I did. He felt something under the floor board and checked the dealer installed, described on the window sticker as 'Chrome Tubular Assist Steps'. Turnes out they were rubbing the frame someplace. I don't know what he did to them but it stopped the noise. Maybe this will help some of you guys...

Not me, I don't have the tube steps. Plus the groaning/chattering noise that I hear, I can also feel in the brake pedal. Hasn't done it yet this week though. I do have several road trips planned for the next 2 months, so maybe I can get it to act up then.

Just Got My 05 3500 Cc Dually & Makes The Same Noise On Deceleration. Hope Someone Finds The Solution This Cant Be Considered Normal On A $50k Truck Even When You Get It For $38k.

Mark

That's what I'm thinking too THUNDER37!!!

Yep, they say it's normal - until we can prove otherwise.

Mine does it too.

Just purchased my '05. I noticed it a day or two after driving it off the dealer's lot.

We need to be careful in trying to identify the problem. Try not to categorize the noise as "it seems to only happen when at altitude; or it only happens when I'm towing; it only happens after a long drive; etc.

I am not at altitude, don't tow and have heard the noise when not taking a long drive. These types of "it only happens when......." can be misleading and confusing for techs reading the thread.

Broadly, I hear the noise when decelerating from hiway speed. It lasts for approximately two seconds. The noise seems to eminate from a point low and beyond the firewall and occurs when applying the brake. In fact, the groan intensifies the harder I depress the brake, then abruptly stops. It sound like pressure is being released.....possibly in the brake system.

It seems to be coming from the same area as the loud fan noise we all know and love.

I have heard the same noise. I was stopped, on the brake, and while turning the wheel my steering was extremely hard to turn, felt like it was binding up. As soon as the drone stopped the steering loosened up.

Is it the hydroboost that assists the steering or does the power steering pump assist the hydroboost.

They seem to work together, well, sometimes they "seem" to not work "together".

Jason

You know, I just sold my powerstroke and bought a new chevy which i so far like. The fords had a very similar issue that was fixed with a high pressure hose change. I don't know if it were the diameter of the hose or its composition, but it would resognate a droning sound through the booster and firewall during pressure fluctuations. Mine had these fluctuations so bad that sometimes you would lose brake pressure(dangerous). This could be similar just not as bad(I hope).

Any more news or fixes for this problem anybody?

I'm new to the dmax and have noticed this sound too, first time when I was decelerating from 80 mph on an Oklahoma freeway. From then on it's been pretty consistant after several freeway miles for the truck to make the noise. I'd classify it as a "pressure induced" thing since it almost "feels" like there's a drag on the driveline. Happens at about 40 mph on the way down.

05 CC 4x4 3/4 w/ 12,000 miles in 10 weeks thru 10 states!

Same here on my new '06, so I don't think it's a valve upgrade or TSB issue, else would have been corrected on the line in July when it was built.

Generally high speeds, but I've had it happen as low as 40. As described above, if I haven't been using the brakes for a few minutes, if I hit the pedal immediately upon releasing the gas, it does it. I thought it was the ABS kicking in to keep the rear discs from locking up, but I also notice it (to a lesser degree) on gentler braking where there's no way the rear would want to lock up.

Hard braking, very loud.
Softer braking, very quiet, but I can still feel it.

It stops if I release and reapply the brakes.
It continues until I release the brakes on hard decel from highway speed.

This truck does stop WAY better than my Tundra did.

Hello all, I dont know if this is exactly what you are hearing but the groaning noise I hear on almost every lly is when the turbo kicks in. @ Idle one can gently press on there accelerator and watch your boost psi, the very second your boost starts to come up you will get a terrible groan, I notice this while driving also, if you let off the pedal and get back into it, the turbo groans. Hope this may help.

I can duplicate it at will on my truck. While sitting in Park/Neutral, I push the brake hard and rev the engine up. I notice it most when I am braking in traffic. I use a heavy foot to stop because traffic speeds change fast sometimes in SoCal and if you keep a good distance from the guy in front only invites others to cut in front... Anyway, I was told that this should be semi normal since the brake system gets its boost from the power steering pump. The only times I have ever noticed this is under heavy breaking in traffic or when I want it to do it. I have only noticed it once while turning but that was while getting off the freeway after a fun commute. I attributed it to hotter than normal fluid temps after all my traffic fun.

Ive heard the same winding noise. Mine is from the engine braking. If you notice when de-accelerating whether on the brake or not and it stops at when you reach 15mph its the engine brake. Its supposed to do it and at 15mph the engine breaking shuts off. Thats what the winding noise was for me. Thanks.

Had my 2005 2500 in twice they changed the steering pump once. It stopped for 2 days and is now doing it again.