No Turbo sound/spool up

[watercross]

Can you only here the turbo under a serious load? I have a 2500 Duramax with swiss cheesed airbox, Banks 4" exhaust, Amsoil air filter, no juice of any kind yet, and run 285's for tires. I only get 14 mpg no matter what. When I recently towed my 4 1/2 foot tall 20ft enclosed aluminum trailer empty weighing in at 1800lb I got only 10mpg running an avg of 70mph no matter what I tried down this staight easy stretch of roads to Oklahoma and I never here the turbo. Even with 4 heavy sleds in the winter time I never here it and loaded, which ain't much, mileage is even worse. Sorry for the long post. Have been a member for over a year and learned a lot from all of you. First diesel for me, happy with everything else so far.

[sdaver]

YOUR SPEEDOMETER IS OFF ABOUT 7% BECAUSE OF YOUR TIRES SO THE MILES RECORDED ON YOUR ODOMETER IS ABOUT 7 % LOW RECOMPUTE.......I DONT HEAR ANY WHINE EITHER BUT MY BOOST GUAGE AND THE SEAT OF MY PANTS SAY ITS WORKING ......DAVE :D I HAVE MY FILTER CONFIGURED THE SAME AS YOU ALONG WITH THE BANKS 4" EXHAUST.

[watercross]

Sorry, forgot to mention that I computed the tire size at 10% already. Seems to be off 1/10 every mile marker so for example if I went 200 miles I marked down 220, which makes my mileage even worse if it's more accuratly 7%.

[MaxRock]

watercross,

I have a bone stock '02, D/ZF. I do hear turbo whine when I'm climbing small hills or put a load on the engine. It is not loud, but I can hear it. Unfortunately, I do not have gauges, so I cannot tell you what boost I'm running.

On another note, I run 255x85-16, close to the same height tire as the 285x75-16. Based on my calculations and real world tracking, I have a 10% error.

MaxRock

[Maxter]

I can hear the turbo winning all the time even empty. I just have to press on the GO pedal and I hear it. Even idling in the driveway, I just press on it and there it goes. I have the K&N Filter and didn't do any modifications to my airbox.

I have the juice since yesterday but it didn't seem to make any noticable difference to the turbo sound, it is still there and VERY evident. I don't only hear the spool up and down but most of the time I just hear it going.

When the window is rolled down, you can hear it louder. I don't really remember how it was without the K&N because I put it in very early after the purchase like a week or so.

Hope you find your answers.

JF.

[Amianthus]

Was your mileage always this bad? If it just started recently, I'd guess that you are losing mileage because of the switch to winter fuel. Or at least, that will have some impact on it. How's your air filter? If it's dirty, that could have an impact also. And have an impact on noisy turbos too. An aftermarket filter may give you what you want and help with mileage.

As for the noisy turbo, your truck isn't designed to be noisy. Most market researchers find that people object to the turbo whistle and they engineer measures to subdue it. You might just have to put up with the quiet.
Tell you what, I'll burn a CD for you of my passenger compartment sounds and the turbo whistle of my truck. Then you can play it at your leasure and turn it off so that you can enjoy the quiet ride when you have passengers along. :D

[watercross]

I added the Amsoil filter about a month ago so I know it's clean. I drove from St.Paul to Oklahoma this past weekend and always filled up at truck stops so I'm not sure when the mixture of #1 & #2 starts and in what regions but that could definitely be an issue. The winters have been so mild recently I haven't really been able to realize a change in mixtures and mileage. I didn't have the Amsoil filter or oil in last winter but all else was the same. I pulled same trailer last winter several times with it loaded with four sleds(still only about 4000lbs total) and never realized this low 10mpg. Maybe I really didn't pay as close attention last winter and only during summer when I travled to all my races, and last weekend they already started mixing the fuels. Either way I'm really worried what my mielage will be when I tow some real weight like you guys. This trailer I pulled empty to Okl. a week ago is only 1,800 lbs and areodynamic, can't even tell it's there. Could my turbo not be ever working and it's just dumping fuel? So many guys said when I did searchs on turbo spool etc. that she whisles, can here it spool up and down etc. I have no special boost gauges etc. and just don't know that much about all thee above. Thanks all, Paul

[Amianthus]

If you have access to it, put in a temporary boost gauge and see what your readings are (or install permanent ones). You may have a faulty wastegate. But, if that were the case you'd be lacking power and you should have some smoke on acceleration. This is perplexing. What has the dealer said? If you've been there.

BTW-55107 is my old stomping grounds.

[Colorado Kid]

On the Duramax I think the Mass AirFlow (MAF)sensor and Manifold Absolute Pressure (MAP) sensor would prevent the smoke on acceleration that is a classic no boost symptom, but you should definately be WAY down on power if you're not making boost.

You're mileage is astonishingly poor though...I can pull a 25' 5th wheel that's a whole lot draggier than the trailer you describe at 68 MPH and get 14 mpg.

I would believe that you couldn't hear the turbo whistle. I only hear it breifly as I start up a hill, or crest over the top. Under light loads it doesn't make any noise, and when it's making power the pitch goes up to where only dors and bats can hear it. I've never driven a turbocharged vehicle where the sound was any less noticible. (Well, I couldn't hear the turbo at all on the rear engined school bus with the Cummins 555 V-8, but that's because the engine driven fan was quite loud, and the turbo was about 28' behind my ears...not to mention the kids!). It wouldn't surprise me if it didn't have to make any boost to pull your trailer on flat graound at 70 MPH...but I'd expect to get 17-19 mpg doing it. Very strange. If you're going to get milage like that you could have saved $4,000 and had an 8.1L.

[watercross]

I should have mentioned the vehicle runs fine, only a tad of fishbite when you really stomp on er. Don't notice any smoke either. I usually fill up locally at a cenex that has good turnover from farmers etc. Haven't had it to a dealer yet till I exhaust all avenues, you know what most of them are going to say when you bring up mileage, but runs fine. I agree on the gasser if this was going to be a constant, especially when for some time diesel ironically has been higher than gas, would miss low end torque eventually thou. In Oklahoma diesel was $1.25 gal. 55107, I know that's St. Paul, but not over familiar with the Cities too much. I'm originally from Northern Mn., a little town called Cotton. I appreciate the help and suggestions fellas. Please suggest as much as possible. I know this isn't much of a problem compared to some of the issues out there, but with the miles I put on chasing snow and racing in the summer this really adds up. I noticed some of the more tech. guys have more guages like we do for our egt's etc. I don't know much about the boost, where it would be mounted etc. Is this much, other than to watch my gating, needed especially when you "Juice" and tow real heavy loads? I'm a very preventive type person. I'm also quite maticulate with my toys and vehicles. I plan on having my Duramax for quite some time and do all the little things like fluids etc. myself. Don't like just anyone touching my stuff unless I really know and trust them. Sorry for the long post, keep the suggestions coming, there are a lot of good experienced people on this site. I've learned a lot. Read every post in 6600 and Drivetrain two months before I ordered mine. Even read the posts way back before I became a member.
Thanks all,
Paul

[BigLakeDMAX]

Paul,

I noticed that some stations in Minnesota started mixing fuel already by 10/15 this year. I've already noticed a drop in mileage from just over 18 to just over 17 mpg. I,too, don't notice alot of turbo noise - not like my '97 6.5 - more like the high pitched noise an old TV makes, and only when accelerating at higher speeds. I have not been able to detect any spool up or down. My truck is totally stock at this point with about 4700 miles on it and is about 6 weeks old.

Was through Cotton two weeks ago grouse hunting. Nice area, not much grouse, though.

[mackin]

watercross

The Banks will drown out a little of the turbo whistle....Mine was very pronounced before, but still present nevertheless......I prefer the sound of the Banks now.....Fuel economy is so over rated .....When I cruise primarily interstate I could break 18 in my truck..I get in city forget it 12-13's....All warm months.....Now with winter blend I can barely break 300 miles on a tank toped off to the Fuel cap screws.......Do the math 34 gallon tank.....SA SA sucky compared to summer even running AC.....I don't even check MPG in the winter.......

MAC

[watercross]

Makin,
I traveled from St. Paul to Okl. right down the freeways straight shot, almost all flat. Going down 40 degrees outside, coming back same way about 65 degrees. Always stopped at major truckstops so they probably had the blend going already being major Interstates. I too believe mileage is over rated. I tried everything from in and out of overdrive to cruise and no cruise, nothing seemed to matter. If this holds, the direction I'm headed pulling a real load in the winter through non-interstate hilly roads I'm going to be looking at 5 mpg... Last winter the truck was so new I spent more time trippin and learning all the bells and whistle's, or non whistles, I didn't pay as close attention as this long summer trip to Okl. I'll have to wait and see...

BigLakeMn.,
Good to here from a more familiar Minnesotan than usual. I agree on the birdies, they really seem to have disappeared. Back in mid 70s when I was 13-14yrs old they were bunched up in droves. I would take a few steps and they would scare me to death. I know they go in like 10 year cycles, and I haven't hunted since I went in the Service in 83, but friends still hunt there today and we still visit,headed there this weekend, but they say things have really changed.
I'll keep trying things, did the 50mph shift to low, we'll see how that goes. I'm afraid to hook up to one of the pro's 5er tri-axel rigs and check the mileage. Thanks for the replies all,
Paul

[FisHn2DMax]

Being in the Medical profession, I wanted to bring up a whole new possibility/theory as to why some of us hear the turbo and others don't?

In my DMax and other bone stock Dmax's I've driven, the Turbo Whine is very present under light load or higher engine RPM's. The Turbo whine is at a very high audible frequencies, up near the top end of normal human hearing range (14K-18K cycles/sec). As some of us age, we can no longer hear well at those high audio frequencies (result of normal aging or past life RocK & Roll concerts, or a nagging wife LoL). I happen to have very sensitive hearing, and the whine can get very annoying at times, so I turn on the radio. When I ask my wife and / or other "middle aged" adult passengers if they can hear the whine, they just look at me as if I'm nuts! (BTW, I am nuts, but that's not the point.) If I ask the kids or their friends, they can all hear it, even in the back seat. It all depends on the frequency range of your hearing and it's sensitivity/decibel range. The average 30-50 something, will probably just barely be able to hear the Turbo whine. If you can't hear it at all, be THANKFUL! Maybe you can't hear your Turbo whine, but look on the on the positive side! You now have a Medical diagnosis as to why sometimes you don't respond to the Mother in-law, Wife & Kids, ~ "You can't hear whining" LOL....!


:D

[Carli_max]

What about your fuel filter?????

[blue_lightning]

Hi folks, first post, love all the great info. Congratulations to all involed here. I keep a 3 ring binder with informative posts I have gleaned from this forum for future reference.
If you really want to hear turbo whine, try an AFE Stage II air filter. Looks BOSS and sounds great. The whistle is very pronounced when under power and goes away at idle and at cruising speed.

[Maxter]

FisHn2DMax :

Your explanation makes perfect sense. I asked my other peoples to tell me if they can hear the whine and most of them could not. They where in their 40s and 50s, I'm 33 and the sound is very very noticable.

On the other end, my portable sawmill has a Kubota 42 hp Turbo-Diesel engine and I never hear the turbo. The power difference between the Turbo and non-turbo model is about 5 hp so I assume the boost is not that high wich makes sens in a stationary work motor.

I asked the Kubota representative about that and he told me that a turbo engine with a non-working turbo would produce very poor performance because of the exaust restrictions caused by the turbo not turning.

[Oongawah]

Hi All,

Seems as though the trucks are unique too. As far as mine. No whine heard at all in any ranges with the stock intake. I'm very sensitive to sounds in my vehicles(wife is even more so). Added the AFE Stage II just before a trip with the family as well as gauges. The first thing my wife asks,"what's that whining sound?". I just looked over with a grin(hehe). She doesn't even ask if I did anything with the engine anymore(LOL). She's a good gal. Anyway, on mine the whine is not any more prevelant wether it's under a load or not. Just like all of them, the turbo spools as exhaust gas pressure increases. It kind of correlates with RPM(kind of, because of the lil bit of lag involved as pressure builds). Now think about the pressure part. If you have equal pressure on both sides of the turbo, no spin. If you increase the pressure on the inlet side it starts to spin. Now for the good part. If you decrease pressure on the exhaust side, the inlet pressure is even more effective. The aftermarket exhaust systems that some of us are using are allowing the inlet pressures to be more effective. Therefore, as in mine, I have stock exhaust and can hear the frequencies from the turbo at certain RPM's/exhaust pressures. Now when I get the Kennedy exhaust next week, I'll report if there is a difference in spool up verses RPM's.
Second to last note. The spool up of the turbo does not correlate with the boost pressure. I can hear the turbo spool up with the lightest touch of the accelerator at cruising speeds(doesn't matter what speed-just cruising). Then if I request power via a harder push on the GO BUTTON, the boost gauge rises as the wastegate closes. Watercross, I installed my boost gauge connection inline with the wastegate actuator hose(right under the 6.6 Diesel cover of which no longer exists on mine). Super easy to do.
Last note. I had to drive without the juice for a couple days while it was being updated. There did not seem to be any difference in boost pressures on the gauge without it(only power difference, and almost no turbo lag). I got about a 10 lb. increase by starving the wastegate actuator, but then the turbo lag came back. Even though the top end was faster, I like the awesome torque, and quick response at low end. Hope this helps, and not confuses. Chuck.

P.S. I get 15MPG driving real hard(can't drive any other way) city and highway mixed. 12MPG pulling the fiver(hard driving too-but not as much).

[Tdawg]

I just put my first tank of fuel in my truck and I got 15 and that's mostly city driving,,and showing off to friends,,also the motor only has 400 miles on it......

[letsgo]

My last hearing test indicated that I had lost my high frequency hearing, doesnt affect the lower frequencies.

As a result I am also unable to hear the high pitch whine of the turbo spooooling up.

But thats my loss.

good luck

[conradv]

I can barely hear it, and my wife looks at me like I'm nuts when I mention it...