Duramax fan noise. It gets louder / worse when punching the gas more, but goes away after Does it drive the water pump too? Or is the water pump operation completely separate from this belt? There are only 3 components related to the belt: the crank, the fan pulley, and the tensioner pulley. The noise may be more noticeable in the first 20% of engine oil life. Is it a bad mount? Or do I need to replace the motor due to a bad Some 2020 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD trucks equipped with the 6. I have noticed the last few days that during acceleration I here excessive air rushing noise New truck, 1,500 miles. 6L L5P because of the major reduction in combustion background noise. Next time it makes the noise, shift to neutral and increase the engine speed-- if it changes-- possible clutch fan is engaged, or idler pulleys have bad bearings. I have the annoying fan clutch kicking in a lot problem while towing but I wanted to lay out my experience today and see what is a good place to start and see if everyone else experiencing the same thing has Trying to figure out what’s causing the sound of my heater fan surging during acceleration even though fan is off ? The low coolant warning has also come on a couple times and it’s not low. 2K views 15 replies 6 participants last post by josb4040 Sep 26, 2024 S Mar 11, 2025 · This morning, my wife took our '24 Sport Diesel to Pilates and noticed the engine fan was running the entire time. Well I am assuming its the clutch fan, sounds and runs like it. I'm a new duramax owner and so far love it . The LLY fan is overdriven. to/c-41-bv Does your car or truck sound like a jet engine? If the cooling fan is on full blast all the time, it might not be the fan's fault! A forum community dedicated to Chevy and GMC Duramax diesel owners and enthusiasts. 6 trucks and still have a 16 Denali 2500HD with 209k miles that was put on a diet. It sounded like something was against the fan blades, a grinding. If its not cooling properly or the pressure sensor is malfunctioning it would make the fan run at higher speed. 6L Duramax diesel engine (RPO L5P) may have a thumping or knocking sound coming from the rear of the engine. That will last Jan 13, 2023 · All in all, the past 2 years I owned and daily drove my 2021 AT4 Duramax, the tones and sounds varied at times but nothing to ever be alarmed about. Dealers should not attempt to compare any customer vehicles exhibiting this noise with other similar vehicles as the noise is different from vehicle to vehicle and this may lead to the incorrect conclusion that the vehicle has a condition. It will be a little while until I need to go somewhere with the truck. When the engine is cold, the engine fan is very loud and turning hard. I am just sitting here scratching my head as to what else I need to check since it is only in reverse unless I received a bad mount and need to swap out the driver side again. Although the fan clutch is commanded off during a cold start, this is the most likely time a vehicle driver will notice that the fan noise is excessive in comparison to engine starts when the fan clutch is disengaged. Feb 6, 2023 · Troubleshooting Loud Fan Noise in New 2023 2500HD Duramax Jump to Latest 6. You can tell it‚Äôs sucking a lot of HP turning. When I accelerated, the noise would Apr 9, 2019 · Come join the discussion about duramax engines, performance, builds, modifications, classifieds, troubleshooting, maintenance, and more! Explore Our Forums 6. It has been somewhat colder today (about 40*) and the last couple days were in Definitely your fan, it robs a lot of power when running. Hey guys, just bought my 1st NEW Duramax (EVER) and have a question. There didn't seem to be a drop in RPM or power, but my fuel mileage is a bit low. 0 duramax, engine fan won’t turn off what could be the cause of it? I have a 2011 2500HD with the duramax lml. I think it is the fan clutch. 2008 GMC Sierra 2500 duramax If the truck is cold and I go to drive off it has what can only be described as a fan/roaring noise and gets louder as you accelerate. any sugestions?? 150 miles, 20's at night, not plugged in. I pulled over looked under the hood and didn't I believe the later Duramax engines has a electronic controlled clutch fan, using input from the coolant sensor and the ECM to turn it on and off. The flap is a bear to get out but its their to seal the fan from re circulating air. Just bought my 06 duramax on the 10th and now im starting to here a mid range pitched whining noise when i accelerate or turn. and Ratio Tech kit. It almost sounds like ( if anyone has heard a air operated engine fan on a semi, right before the fan kicks you can hear the air engaging the fan)! Recently had my 07 classic LBZ tuned (EFI LIVE) . Thanks! BlkSlvrdo129 4,928 posts · Joined 2009 #8 · May 31, 2011 Never noticed an unusually loud fan noise on mine, but we also don't have this "heat" thing you southerners seem to always talk about :crazy: For sale Build thread - Parts sale thread [SIGPIC] [/SIGPIC] Reply Like OKLAGMCRUISER So a few times lately I have noticed that when I start the truck up in the morning after sitting all night and let it warm up some and drive away the clutch fan is own and it takes a few blocks to go off. Looking around If your Chevy or GMC HD truck's engine is running hot or the fan is making noise, the fan clutch might be failing. It does My fan is pretty loud. Hi, construction guy here, definitely not a mechanic. the engine began extreme engine braking whenever my foot was off the gas and running at really high rpms when it normally shifts smoothly and I’ve tried listening with my head under the hood while someone revs it up and down, but the engine and fan noise are too loud. A rattling or flapping noise is often caused by loose or damaged fan blades. At 1200 rpms there is noticeable noise in the dash. Thanks for the response. Dealer says 125 trucks have been registered with GM with the same noise. 3 L V8 2WD with 700 miles on it. is this louder instant Background: I'm driving a 2007 Sierra Classic 2500 HD LBZ with 89,500 miles. However it goes away after a while, today it did it first time I Just recently when i would start my truck after it has sat over night or most of the day and the engine is cold it would sound like the fan is running loud when i start driving. Come join the discussion about modifications, towing, classifieds, troubleshooting, maintenance, and more! I appreciate the help, especially the video. Ok guys and gals. When I first turn my truck on, whether its first thing in the morning or after its been running for an hour and it sits for lets say 20-30 minutes; when I first take off my fan makes a loud noise, almost like a ticking sound. Trans temp was just over 200. 6 starts and stops but still running on high after starting. usually about a mile later it will stop. Diesel fuel grades sold at the pump will change with the seasons from summer blends to winter blends. Fuel Assault 18x9 +20 offset, LT35x12. That is what you have been hearing, an inefficient fan/pulley combination. my gmc 3500 duramax started behaving differently today while towing my empty 18’ flatbed trailer. I am getting a fan noise that is constantly kicking on and off. Are all diesels like this or is this particular to the new LBZ? Symptoms of a bad engine clutch fan and how to test if it has failed. The very first time i started when temps got below 40 degrees at night, i have what almost sounds like a bad bearing in fan or one of pulleys. It actually sounded I'm wondering if you are talking "diesel" noise or are you hearing fan noise. Also, how to replace a clutch fan. Come join the discussion about modifications, towing, classifieds, troubleshooting, maintenance, and more! Engine fan noise seems very loud last few days. Well, Alabama is now getting a constant 90 degree weather and with that I've started noticing a VERY loud noise around the radiator area (I know nothing about radiator/ac fans). Don't own an L5P but I know they have a VERY large radiator fan that required them to add another fan belt just to drive it. When I took the new LBZ for a test drive, both the salesman and I noticed the noise from the fan clutch, then after five minutes or so, the noise went away. Something vibrating or rubbing? Customer: I have a 2004 2500HD Duramax. I'll take it to the dealer Monday morning. With the exception of the S&B intake and MBRP exhaust, I believe the engine is stock. It changes with rpm and you can hear in cab and while driving threw first couple gears. So unless the fan pulley also runs the water pump, I'm certain it's the fan clutch making the noise. com https://1aau. The fan clutch appears to be functioning properly since the fan operates even after the engine stops. It may be more noticeable on the 6. Goes away after truck is completely Is it all the time or only when its hot out and the engine is warm? sounds like it's your radiator fan based on your description. That normal? It spins freely when the truck is off and it's not always loud like that but when it's spinning fast, sucker is crazy loud! Sent from my iPhone using Tapatalk check the rubber flap that seals around the shroud, mine was curled under at the top and was protruding through into the fan blade area. Today while driving around town as I always do, I kept hearing the fan, especially up hills or in 2nd gear. . Dealership says it is covered under the #16-NA-32 Bulletin on common engine noises Duramax 6. I had one clutch fan go bad, it wouldn't engage at all, and the new replacement acted like the old one about the same frequency on cold starts. Mine makes all the little whining and clicking noises. 2002 Chevy 2500HD Crew - Original owner - 470,000 miles so far. I've searched and haven't found this exact topic. It is defineatly not the fan. Is it the fuel pump and is this common???????? I Still have the stock fuel system. I will take it to a dealer today if I can find one. my question is with my 04 LLY ,the engine "rattle" seems to hit a point under hard exeleration where it seems to intensify or get louder. 3) and the noise seems to be happening more often when I use the remote start. I have a 16 Denali 2500 HD. I am camping in the mountains now and have developed a problem with the truck and need advice. Is this what I am hearing and if so why is the clutch kicking in when the engine is cold? A forum community dedicated to Chevy and GMC Duramax diesel owners and enthusiasts. No codes or CEL are shown. I believe it is the fan clutch, but am not 100 A grinding or screeching noise usually indicates a problem with the fan motor bearings. This weekend, 180 miles into towing 5000 lbs. When I turn the fan speed up on the heat or ac, when it gets to the top couple of speeds I feel a vibration in the firewall/floorboard and the motor makes a rattling noise. What is an engine Fan Clutch? 2017 Silverado, Duramax, LTZ, L5P engine. The fan did this for the entire 300-mile trip. The noise may be Shop for New Auto Parts at 1AAuto. When started the engine fan is running full blast. Here is a link to a video with the noise. Nov 9, 2024 · I then heard a very obvious groaning sound coming from the front of the engine bay, toward the fan and shroud as far as I can tell. My truck is an '09 1500 (5. The fan would turn on for a couple of minutes and then turn off for a couple of minutes. Since the tune its making a loud noise about 10 seconds after its shut off. 2L Diesel Engine Suspension & Steering - 2001 - 2010 Home Forums GM Diesel Engines Google "fan drive ratio" and duramax, together. I‚Äôve had my 07 3500 for a couple weeks now and swear I haven‚Äôt heard this before. I recently decided to buy a Duramax kinda on a whim and am a little puzzled by something. Is the fan easy to turn with the engine off-?? Just traded my 2018 2500 Duramax for a new 2020 2500 L5P and notice a throbbing sound at idle when the engine is warmed up ( currently 2200km). Or, fluid may bleed from the storage chamber into the fluid coupling of the cooling fan clutch while the engine is off. the power on the truck seems a little weak compared to what it does when it finally stops with the noise. Over the past week, I had been noticing a whine that seemed to vary with RPM; higher RPM, higher pitch noise. ive ben around other diesels and owned others . 2020 GMC AT4 HD, Crew Cab 4x4. They claim it is a heater hose under the dash and since over 5 have been Home Forums Chevy / GMC Duramax 2017+ L5P Forums 2017-19 GM T-K2 Platform Powertrain It happens everytime right before it starts the hissing noise out of the exhaust like when the vanes are opening or closing. It sounds like a loud humming sound or a vibration. Here is the problem. When the light is on, it is accompanied by loud engine fan noise, mainly under acceleration. 38"). About every 5 or 10 minutes, the engine fax will engage and cause MASSIVE fan noise. A check Aug 1, 2007 · I jus purchased a used 2005 2500HD Duramax yesterday. 6L V8 diesel engine. The truck is a 2023 GMC AT4 HD! Have owned many used high mile 6. My 2007 Duramax diesel is making a loud noise that resembles the fan continuing to run after the engine has reached its operating temperature. in triple diget temps the clutch fan kicked in hard and I heard a noise I've never heard in 80000 miles. If you're not Sure what's wrong with a Customer's fan clutch, this list of the Most common fan clutch Noises will help you make an accurate Diagnosis. Thanks Hey guys, New to the site, definitely the best board on the web for GM diesels. ambient temps, fuel grades, all can play a factor of the sounds a diesel makes. Kinda sounds like a lawn mower or leaf blower on the videos I took and is less obvious than it is in person. My personal truck is a 2007 GMC Sierra LBZ CCSB 4x4 with HSP piping, Danville 68stage2r turbo, PPE manifolds and up-pipes, Limitless 1078 TC, Stock trans with Trans Go Jr. 2024 Denali HD Duramax Tricoat white - De-badged tailgate, 35% Ceramic tint, Bora wheel spacers (1. What can i do to make the noise stop I cant hear it when the radio is up or the windows are down driving through town but the truck has 151,000 miles on it. So why would the clutch I have a 2015 Sierra 5. I've looked around a bit and can't find any answers it seems. I know that shutdown makes some noise, but the growling noise was real loud, only when hot, fan clutch makes sense. my scanner coolant temp states 178-183 but the dash says 212 Can someone explain the cooling process as it references the thermostats, fan relay, or sensor? How does it get hot enough to allow I've noticed on only a couple of occasions that when I get in my truck and start it and go when engine is cold that I get a loud noise that appears to be coming from the clutch fan. The temperature was around 32°F, so there was no reason for it to be on. This occurs at idle and may seem to be louder when standing just behind the driver’s front wheel. Very close to hitting the fan. The earlier (pre-04) truck had a lower fan drive ratio, and it is quieter, and more efficient. The fan sounds well like a fan and this sounds like louder than normal diesel racket. I can clear the code with an after market tool, but it is unable to read the code. The noise is a normal operating • Diesel Engine Tick: Diesel engine tick is present in all diesel engines produced in the last 20 years and does not have any impact on engine reliability and durability. 6L, but this is not the ticking or cycling that I have The AC can affect fan speed as well. Not installed properly from brand new. 5L Diesel Engine Duramax First Generation: 2001-2004 (LB7) Duramax Second Generation: 2004. The noise last for 8 to 10 seconds. 5R18 Nitto Ridge Grapplers. All stock with the exception of a lift pump. 2020 sileverado 3. Im new to owning a Duramax, and have only had cummins trucks in the past. but it sounds like a school bus its so loud. I noticed a loud roar from the fan while driving at night, but it wasn't close to overheating at all. Discover common Duramax diesel problems across generations, including LB7, LBZ, LML, and LMM Duramax problems, with tips for every model. Mine will go back to normal after a few minutes of driving worst case. almost like a gasoline rig detonating . Even after restarting the vehicle to drive home and again after refueling, the fan kept running. 5-2005 (LLY) 6. I can't figure out why the fan is constantly running. I just starting using the A/C unit, and when fan is running at high, sounds like a jet engine and I know there is a post already going about this but that one is not what im going for. I can just barely hear it and it seems to be coming from the top of the engine maybe towards the back. When I drive, the temp stays at about 100C ( Canada ) ( 212 F ) and does not really move much. I cannot make it make the noise in anything other than reverse, and only if the engine is off idle. No worries man. It’s a 2011 LML. Does the new models have a different sound to them? It is hard to describe Is the radiator fan constantly spinning a little bit? I replaced my thermostats and noticed it. anyone have this i have a 2005 gmc lly and the fan is way louder than i expected when i bought it, i just bought it last week and it is my first diesel. 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