Jump to content

Loud air blowing noise under acceleration, duramax


preston

Recommended Posts

Posted

Loud air duct blowing noise under mild acceleration. It doesn't do it under all conditions in fact full throttle I usually don't hear it. But under load at lower speeds and throttle positions, kind of sounds like when a big panel truck goes by under load and you hear that huge air rushing noise above the sound of the engine.

Or for example  if you took the air box off a car. I'm not sure if I'm losing power as like I said under full throttle it feels strong, but it might be a little bit soft in these load situations when I hear the noise.

 

First though is obviously a leak somewhere in the charge air system, but what's odd about it is as stated above its not consistent under load. I don't have a boost gauge but I've had enough of them that I have a pretty good idea of what the boost response looks like under driving and there are lots of times I feel it would be making boost but its not making the sound.

And when it does make the sound it doesn't come on gradually its like some dump valve is opneing. Its hard to pinpoint where its coming from other than "engine bay".

 

Its probably a leak of some sort in the charge system. I poked around best I could without taking anything apart.

 I just wanted to make sure there wasn't some "dump valve" being triggered incorrectly or somethin or some other possible cause because the sound just doesn't seem to act like I think a leak would.

Posted

DMax turbo’s use VVT so no dump valve/ waste gate

Almost sounds like your cooling fan is cycling as per your noise description

 

 

 

 

 

 

Grizzly

 

 

 

Posted

Its a 2015 Sierra.

 

Interesting thought about the fan - it does kind of sound like that although its awfully loud not sure the fan at full blast would be that loud over the engine. It would explain the way it seems to come on so strongly ie without any ramping in and out and might explain the randomness of it (although it occurs frequently its not predictable except that I think it only happens under some type of load). Detriments to that theory are though that it seems to have some level of tracking with the engine speed. Not entirely sure though.  I've been noticing it over the last week or so but I need to go out and do some critical driving to see if/how/when I can trigger it, and roll down the windows, back the throttle off etc. 

 

>Dont know what year you have but it sounds like the waste gate is stuck on the turbo

 

Hm, I would agree if you said blow off valve or dump valve. Seems like a wastegate would just reduce boost, not leak air (and if it did leak it would be exhaust noise not blowing air).

 

 

Posted

If this was a turbo vain or a boost leak issue you would get a engine light imo, you might experience lack of power , frequent regen’s , etc

I had a lml and the fan would roar louder than the engine




Grizzlyltz

Posted

A check engine light is on actually, not sure when it popped up (recently). Truck is new to me so I haven't bought a scan tool yet.

I'd been doing a lot of work to the truck with the battery connected/disconnected so I wasn't putting two and two together as I thought it might be a false alarm - Guess I'll need to grab a scan tool and confirm.

Probably get a code "low charge pressure" - doesn't help me find it though !

  • 4 weeks later...
Posted

Preston, did you ever figure out what was going on with your truck? I have the same model Duramax and I have the same thing happening on mine. It's intermittent and I haven't noticed that certain conditions cause it but it is incredibly loud when it does happen. I guess I am inclined to believe it is the fan but I'm not sure. 

Archived

This topic is now archived and is closed to further replies.

  • Latest Articles

  • Posts

    • I think the answer is it's a stock 5.7 Hemi with a 3.0L blower bolted onto it 😉   Practically, because a blower introduces a lot of high pressure, severe thermal stress, and extreme mechanical loads on an engine. Things still need a little time to seat and get used to moving under load.   Sarcastically, because it's a Stellantis/ 5.7 Hemi and those things need all the help they can get!!
    • It's been a little over three weeks since my second knee replacement.  I can now walk around the house without a walker or cane but still have a lot of healing ahead.  This morning I was able to bring a cup of coffee to my wife in bed.  A few days ago, this coffee would have ended up on the kitchen floor!  Knee replacement surgery is very common and will typically enhance the recipient's future quality of life. However, the recovery process can present significant challenges, pain and discomfort. I encourage anyone facing a recommended total knee replacement to welcome the opportunity.  Just be aware that your body may take several months to fully welcome the new parts! 
    • The Germans basically didn't make the list. There aren't a lot of shade-tree mechanics who work on them in general. At some point the economic equation of keeping a car alive favors junking it. Anecdote/experience tells me this is the case versus actual bad engines/engineering. Not that there isn't any, but there are definitely notable excellent examples. The 2.0 diesels will go forever and ever if one keeps the car around it running. The 2.0 gas cars eventually wear out their turbos but the block below it is usually still solid as a rock. BMW inline 6's same thing. Mercedes diesels of yesteryear, not uncommon to see 250k out of those engines, easy.     Link to the synopsis of the study: https://www.iseecars.com/longest-lasting-cars-study
    • 0w20 is recommended in the Sequoia. 0w16 in the Highlander Hybrid.   I think you make a compelling case for both the quality and frequency of maintenance but I wouldn't go so far as to plot a linear relationship between longevity and oil weight 😉   The list is interesting and leaves me with some questions. The Silverado 1500 is 12.9% likely while the GMC Sierra 1500 is only 10.8% likely. Arguably, they're the same truck, so other factors must be influencing the outcome.   The Honda Odyssey ranks #12 at 13% likely. Great. Rest assured we'll never stop hearing about the dang thing LOL.   There's a bit of a spread between the 4Runner (32.9%) and Tacoma (25.3%). Both overlap on the same 4.0 for many years although the Tacoma used a 3.5 for the last 10-12ish. I wonder if that's related to use-case or if it's suggesting the 3.5 isn't quite as up to the task, or maybe something else fails mechanically.   Ram at 3.5% overall likely, but the Ram 3500 holds the top spot on the Heavy Duty Models at 39.7%. One might say the Cummins is a ringer and provides an unfair advantage. I don't think it's fair/accurate to pit the GM Fullsize 1500's in a list with HD's which are basically medium-duty wearing a 3500 badge.   The Tahoe and Suburban hold spots #15 and #8, respectively, on the longest lasting SUV's list. What's the difference? One's got a shorter butt, unless they're also counting the 2500/3500 Suburbans in those numbers.   The GMC Canyon gets a 1.4% increase over its twin brother Colorado. Why, because it's prettier?   SO many questions...
    • Have the aftermarket system removed an re-test.  Its pretty much the only way to know if there is still an issue that is the truck and not from that.  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...