Jump to content

Longtubes/catless y pipe sewing machine

scottie350

By scottie350
in Engines & Drivetrain

Recommended Posts

scottie350 Enthusiast

scottie350

Posted
Posted

Hey guys, so this is on a 16 Sierra 5.3. After going to LTs and catless y pipe i seem to have whats best described as a loud sewing machine sound.  I know stock manifolds are thicker which equals more valvetrain noise but is everyone just dealing with this obnoxious noise? 

 

I cheaped out a bit and went with pace-setters but i did have cause. Ive seen several dynos of huge gains on pacesetters on these trucks and reviews from guys saying theyve lasted them several years and still going, which by then id be into a new truck anyway. 

 

Ive checked for a leak leak, loose plugs, caps, nothing i can find.

 

Thinking pacesetter headers and y pipe gauge size likely thinner ive been searching. Oddly enough PS are the same or thicker gauge than most recommended brands. Which is where im now stumped with this sound. 

 

It doesnt come from the headers, it primarily seems to reverb through the y pipe area. Can hear it at cold start, or at higher gear low rpm cruising from beneath the front seats, like a loud ass sewing machine. Ive seen posts on the vette forums that this tends to be a tad normal over there with catless LTs, not much on these trucks tho.  

 

So what, is this common and u guys deal or? PS uses 16 gauge on the lts and 16 gauge on the y pipe, kooks are 18 gauge LT and 16 gauge y pipe.   Honestly super annoyed with the sound, ready to put the stocks back on thats how annoying it is to me.

300 Blackout Enthusiast

300 Blackout

Posted
Posted

I have speed engineering long tubes, no cats, dual 3” exhaust with an x pipe. The metal is 304 stainless and 16 gauge. I do not have any such noise.

The engine itself, I can hear the valve-train doing its thing. Honestly, not really bothersome to me. The exhaust produces no such sound. Just a deep rumble.

I tuned out V4 mode so my truck is always in V8.

scottie350 Enthusiast

scottie350

Posted
  • Author
Posted
13 hours ago, 300 Blackout said:

I have speed engineering long tubes, no cats, dual 3” exhaust with an x pipe. The metal is 304 stainless and 16 gauge. I do not have any such noise.

The engine itself, I can hear the valve-train doing its thing. Honestly, not really bothersome to me. The exhaust produces no such sound. Just a deep rumble.

I tuned out V4 mode so my truck is always in V8.

Thanks for the reply. Mines custom tuned with v4 shut off. Sound doesnt come from engine, dominantly radiates from the y pipe.

Something ive been considering is where it ys into single pipe causing the increased noise. Because it seems to be radiating from the y pipe this seems logical.

 

  Ive been wondering myself if going to duals with an x pipe would drop this off. By your setup i could be on the right track.

 

Im going to take the truck to the custom exhaust shop and have him take a look and then see what he thinks.

 

 

 

Barman84 Enthusiast

Barman84

Posted
Posted
On 1/19/2019 at 10:18 PM, 300 Blackout said:

I have speed engineering long tubes, no cats, dual 3” exhaust with an x pipe. The metal is 304 stainless and 16 gauge. I do not have any such noise.

The engine itself, I can hear the valve-train doing its thing. Honestly, not really bothersome to me. The exhaust produces no such sound. Just a deep rumble.

I tuned out V4 mode so my truck is always in V8.

What did you do about your rear 02s???

300 Blackout Enthusiast

300 Blackout

Posted
Posted
What did you do about your rear 02s???

I disconnected them and am running with a check engine light for now. I put money down on a supercharger and the tune that comes with it can be modified to shut off the rear O2s. Unfortunately, the truck was just rear-ended last week and I’m in a rental until I find out if they are gonna replace my frame.
scottie350 Enthusiast

scottie350

Posted
  • Author
Posted
On 2019-01-27 at 11:15 AM, Barman84 said:

What did you do about your rear 02s???

Clipped mine to keep the plug in so it doesnt ruin the plugs in the harness, then tuned them out. If ever need to i can splice the o2s back on. 

scottie350 Enthusiast

scottie350

Posted
  • Author
Posted
On 2019-01-27 at 1:04 PM, DirtyMarcus said:

Most LS and LS based engines make the "sewing machine" sounds.  Its usually the rocker arms making the noise.  Not an issue just noise.  However, if you want to fix it due the trunion upgrade.  https://www.texas-speed.com/p-5982-che-lslt-trunion-kit-for-stock-rockers-bushings.aspx

Yeah this has been my consensus recently. Most info i find on the vette forums but guys have mentioned this noise from ls engines. One guy posted a vid and its exactly what mine sounds like. Normal at idle and even in park revving, notice it at higher gear/low rpm under load.  Havent found a confirmation if a true dual with x pipe will lessen it, 300blackout says doesnt have this noise w his setup. Ill check out the kit you posted. Thanks for the confirmation Marcus, at the very least, perhaps i just need a louder exhaust baha

crushNchowda Senior Enthusiast

crushNchowda

Posted
Posted

google "sewing machine noise" on an GM LSx/LTx forum & you'll find more threads citing similar whether it be injectors, rockers, valves or intake noise or a combo of it all -but its not uncommon.....you did get the cheapest headers money can buy, your $$$ your choice - correct they'll def boost HP, but they're constructed of aluminized mild steel, not sure on the gauge but probably is thicker than most competitors made outta stainless b/c there's going to be oxidization/pitting occuring w/ the PS's & they need to hold up, I would've had them ceramic coated if it were me....

 

At any rate I also notice these trucks have more sound emitting from the lower driver's footwell area, I believe someone @ some point tracked it down to lack of heat shield/sound deadening material in a certain area near the steering column? Anyhow - ever since I added my Gibson exhaust I've had more sound coming in cabin engine & exhaust, I thought was exhaust leak initially but crawling underneath don't see any evidence of such & after coming across the thread I mention above chalked it up to that. The dealer couldn't locate any leaks either (not that that means much)

 

I don't have headers, but I can imagine the sound from the engine bay would be MUCH louder since I can hear it now @ some throttle/rpm levels, headers magnify drivetrain/engine sounds for sure.  

DirtyMarcus Enthusiast

DirtyMarcus

Posted
Posted
5 hours ago, scottie350 said:

Yeah this has been my consensus recently. Most info i find on the vette forums but guys have mentioned this noise from ls engines. One guy posted a vid and its exactly what mine sounds like. Normal at idle and even in park revving, notice it at higher gear/low rpm under load.  Havent found a confirmation if a true dual with x pipe will lessen it, 300blackout says doesnt have this noise w his setup. Ill check out the kit you posted. Thanks for the confirmation Marcus, at the very least, perhaps i just need a louder exhaust baha

I will say this, on my ls1 swapped mustang i have cutouts so basically straight from the headers exhaust.  I can hear the rocker noise over the exhaust outside the car and with the hood popped its extremely noticeable.  Inside the car I cant hear it though.  I plan to do the trunion upgrade eventually but its not something that bothers me too much.

scottie350 Enthusiast

scottie350

Posted
  • Author
Posted
2 minutes ago, DirtyMarcus said:

I will say this, on my ls1 swapped mustang i have cutouts so basically straight from the headers exhaust.  I can hear the rocker noise over the exhaust outside the car and with the hood popped its extremely noticeable.  Inside the car I cant hear it though.  I plan to do the trunion upgrade eventually but its not something that bothers me too much.

Welll crap, it drives me nuts, i may have to do the upgrade. Im super ocd about some things.

scottie350 Enthusiast

scottie350

Posted
  • Author
Posted
12 hours ago, crushNchowda said:

google "sewing machine noise" on an GM LSx/LTx forum & you'll find more threads citing similar whether it be injectors, rockers, valves or intake noise or a combo of it all -but its not uncommon.....you did get the cheapest headers money can buy, your $$$ your choice - correct they'll def boost HP, but they're constructed of aluminized mild steel, not sure on the gauge but probably is thicker than most competitors made outta stainless b/c there's going to be oxidization/pitting occuring w/ the PS's & they need to hold up, I would've had them ceramic coated if it were me....

 

At any rate I also notice these trucks have more sound emitting from the lower driver's footwell area, I believe someone @ some point tracked it down to lack of heat shield/sound deadening material in a certain area near the steering column? Anyhow - ever since I added my Gibson exhaust I've had more sound coming in cabin engine & exhaust, I thought was exhaust leak initially but crawling underneath don't see any evidence of such & after coming across the thread I mention above chalked it up to that. The dealer couldn't locate any leaks either (not that that means much)

 

I don't have headers, but I can imagine the sound from the engine bay would be MUCH louder since I can hear it now @ some throttle/rpm levels, headers magnify drivetrain/engine sounds for sure.  

I normally dont keep my vehicles long. My intention was to get some more fun out of it while i had it and then swap it back to stock before i traded it. So looking at dynos done settled to save cash as i knew id get that. Im not worried about longevity, theyll last just fine aslong as im gonna have the truck. I had the headers stripped and coated myself, the extra 300 for the ceramic they send it in isnt worth it from the countless hours searching i did, it tends to chip off as ANY bump can damage the coating in transit, got em coated locally for half the price.

 

Given the gauge of metal used i was curious if others hear this or if i was missings something. Oddly i could only find searches leading me to the vette forums but they said the same thing over there about the ls motors and headers/catless... valvetrain noise. The video a forumer there and his explanation of the conditions confirmed thats what im hearing.

 

Ive modified most of my vehicles, some quite heavily, never heard this before without finding a problem, first time on an ls engine so its been bugging the hell out of me. Not finding a culprit i needed to know if it was a normal noise or if i was overlooking something. Seems its normal though, and either ill have to learn to live with it or try the rocker bushing upgrade that Marcus posted

scottie350 Enthusiast

scottie350

Posted
  • Author
Posted
On 2019-01-19 at 10:18 PM, 300 Blackout said:

I have speed engineering long tubes, no cats, dual 3” exhaust with an x pipe. The metal is 304 stainless and 16 gauge. I do not have any such noise.

The engine itself, I can hear the valve-train doing its thing. Honestly, not really bothersome to me. The exhaust produces no such sound. Just a deep rumble.

I tuned out V4 mode so my truck is always in V8.

Btw just realized ur using SE LTs, is ur exhaust thier true dual kit also?

300 Blackout Enthusiast

300 Blackout

Posted
Posted
Btw just realized ur using SE LTs, is ur exhaust thier true dual kit also?

 

Yes, it’s their true dual exhaust and their headers. Exhaust sounded awesome but the drone was killer so I added two Borla Pro XS mufflers before the SE mufflers. Drone got worse. Now, I’m gonna delete the SE mufflers and add high flow cats just after the x-pipe. After the cats I’ll keep the Borla mufflers then a dual exit in front of the passenger side rear tire. Hopefully that will fix the drone and keep it quiet enough for the neighbors.

 

I do hear my valve train at idle or when pulling through a drive thru but it isn’t a sound that I hear in the exhaust.

 

Right now, the loaner I’m driving is a 2018 F-150 with 3,000 miles on it. It’s no different than our trucks. It has its fair share of engine noises and ticks that I could drive myself nuts with trying to find.

 

scottie350 Enthusiast

scottie350

Posted
  • Author
Posted
10 minutes ago, 300 Blackout said:

 

Yes, it’s their true dual exhaust and their headers. Exhaust sounded awesome but the drone was killer so I added two Borla Pro XS mufflers before the SE mufflers. Drone got worse. Now, I’m gonna delete the SE mufflers and add high flow cats just after the x-pipe. After the cats I’ll keep the Borla mufflers then a dual exit in front of the passenger side rear tire. Hopefully that will fix the drone and keep it quiet enough for the neighbors.

 

I do hear my valve train at idle or when pulling through a drive thru but it isn’t a sound that I hear in the exhaust.

 

Right now, the loaner I’m driving is a 2018 F-150 with 3,000 miles on it. It’s no different than our trucks. It has its fair share of engine noises and ticks that I could drive myself nuts with trying to find.

 

Ive been looking at that kit, how loud was it w the SE mufflers? Mostly at cold start? 530am starts wondering how POd neighbors gonna be lol. 

 

As for the valvetrain i likely hear it so much bc im focusing so much on it when driving, but yeah def at drive throughs  ill deal w that later haha

Archived

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

Go to topic listing

  • Latest Articles

  • Posts

    • Grumpy Bear
      Gas Prices

      By Grumpy Bear · Posted

      $3.90 to $4.50 depending on the brand and location of the station. 87 regular. 
    • Grumpy Bear
      Valvoline R&P Fuel System Cleaner

      By Grumpy Bear · Posted

      Guys that read Dizzy's thread know that eons ago after multiple manifold pulls to clear the CCV orifice I converted it to a PCV system with an orifice below it via the valve cover. The blow-by (sticky rings) was so bad it was impossible to keep clean and accumulated water in the oil in the winter when the moisture would freeze in the fresh air side. The PCV functioning mainly as a check valve. I carefully sized the orifice to reproduce the factory values for crankcase pressure at idle.    Well...took a slug of oil to get my attention but the ring seal improvement meant the system was over drafting sucking oil up and out the breather. (V8 guys with orifice systems are nodding their heads). So today I choked it down...allot....to replicate the "just enough to hold a piece of paper on the fresh air side at idle". May still be to much but I'm working with shims at the moment. When I get it sorted I'll make a proper plate and plug. Perhaps using carburetor jets to tune it.    So I guess this means it isn't my imagination.    Dizzy is a pig guys so don't go expecting huge moves in equipment (your equipment) that is in much better shape. A needle valve....lord that just came to me....
    • Jus Cruisin
      2027 3.0l - ordered

      By Jus Cruisin · Posted

      I had a new engine installed with under 5,000 miles. It shut off coming around a residential street corner and wouldn't restart. Dealer indicated it seized. New one has been fine since with 10,000 miles on the replaced engine. Annoying but I was given a loaner for the 5 weeks it was down. I won't go with the 6.2l gasser so it's 3.0l again. I love the economy and it tows my enclosed car trailer just fine. 
    • calgator73
      Lesson relearned on basic diagnostics...

      By calgator73 · Posted

      Coming back from towing a car to my daughter in Nashville truck started making a screaming noise from underneath.  Pulled over placed in park and sure enough whining noise from underneath.  Dropped at the dealer fearing new tranny or another front pump/cover replacement.  Service writer said it sounded like the tranny too...  Well $300, new idler and a belt all is good.  Pop the hood and give a listen. lol  Now I'm telling dealers I'm no longer interested in a new truck.
    • newdude
      OIL CONSUMPTION

      By newdude · Posted

      HD uses the 6.6 gas.   Oil consumption while heavy working is considered normal.  1 quart per 100 gallons of fuel is the normal rate above 8600lbs GVWR.  If more than that, it is considered excessive.   They will have to perform an oil consumption test using the guidelines in TSB 03-06-01-023J.     Information on Engine Oil Consumption Guidelines All engines require oil to lubricate and protect the load bearing and internal moving parts from wear including cylinder walls, pistons, and piston rings. When a piston moves down its cylinder, a thin film of oil is left on the cylinder wall. During the combustion process, part of this oil layer is consumed. As a result, varying rates of oil consumption are accepted as normal in all engines. Oil Consumption Oil usage has a direct relationship with the amount of fuel used. The harder an engine works, the more fuel and oil it will use. Therefore, oil usage as a factor of fuel usage is a more accurate indicator of acceptable oil consumption levels than vehicle mileage for vehicles at or above 8600 GVW. The accepted rate of oil consumption for gasoline engines in vehicles at or above 8600 GVW is 1 liter (1 qt) within 400 liters (100 gallons) of fuel used. This rate only applies to vehicles under warranty, maintained in accordance with the appropriate maintenance schedule, driven at legal speeds and within design intent of the vehicle. Many factors can affect an owner's concern with oil consumption. Driving habits and vehicle maintenance vary from owner to owner. Thoroughly evaluate each case before deciding whether the vehicle in question has abnormal engine oil consumption. Gasket and External Leaks Inspect the oil pans, engine covers, and the engine oil cooler for leakage. Inspect for oil leakage into the engine coolant. Improper Reading of the Oil Level Indicator (Dipstick) The vehicle must be parked on a level surface to obtain accurate oil level readings. Verify that the dipstick tube is fully seated in the block. When checking the oil level, make sure the dipstick is wiped clean before taking an oil level reading and fully depress the dipstick until the shoulder bottoms out on the dipstick tube. The dipstick should be the proper part number for the engine/vehicle that is being checked. Not Waiting Long Enough After Running Engine to Check Oil Level The vehicle should be allowed to sit for at least 15 minutes, after the engine has been shut off, before taking an oil level reading to assure the oil has had enough time to drain back into the crankcase. In order to ensure accurate results, the temperature of the oil should be close to the same temperature as the last time the oil level was checked. Improper Oil Fill After an Oil Change Following an oil change, verify that the proper amount and type of oil was put in the engine and that the oil level on the dipstick is not above the full mark or below the add marks. Refer to the Owner's Manual or Service Manual for information on recommended oil quantity, viscosity, and quality. High Speed or High RPM Driving Continuous driving at high speeds/high RPMs may increase oil consumption. Because this may not always be an everyday occurrence, it is hard to determine exactly how much the oil economy will be affected. Towing or Heavy Usage Towing a trailer or hauling additional weight will increase oil consumption. Large frontal area trailers will further increase the work required from the engine, especially at highway speeds, and thus increases the rate of oil consumption. PTO Operation Operation of a PTO will increase fuel and oil usage, as the PTO driven accessory uses engine power to operate. Crankcase Ventilation System Verify that the positive crankcase ventilation (PCV) system is operating properly. Blockages, restrictions, or damage to the PCV system can result in increased oil use. Oil Dilution from Condensation On vehicles that are usually driven short distances, less than 8 km (5 mi), especially in colder weather, condensation generated from cold engine operation may not get hot enough to evaporate out of the oil. When this occurs, the dipstick may indicate that the oil level is over-full. Subsequent driving on a trip of sufficient length to enable normal engine operating temperature for 30 minutes or more, in order to vaporize excess moisture, may give the customer the impression of excessive oil consumption. Engine Temperature If an engine is run at overheated temperatures (see Owner's Manual or Service Manual) for more than brief periods, oil will oxidize at a faster than normal rate. In addition, gaskets may distort, piston rings may stick, and excessive wear may result. Verify that all cooling system components are in proper working order. Engine Wear Piston scuffing, excessive piston-to-wall clearance, tapered or out of round cylinders, worn, damaged or improperly installed valve guides, seals and piston rings will all cause an increase in oil consumption. Measurement of Oil Consumption Engines require a period of time to BREAK IN so that moving parts are properly seated. Therefore, oil economy should not be tested until the vehicle has accumulated at least 6400 km (4000 mi). An exception would be allowed only if an engine is reported to be using more than 0.946 liter (1 qt) in 1600 km (1000 mi).   Verify that the engine has no external leaks. Repair as necessary. Verify that the engine is at normal operating temperature (see Owner's Manual or Service Manual). Park the vehicle on a level surface. Wait at least 15 minutes, after the engine is shut off, before checking the oil level to make sure that most of the oil has had time to drain back into the crankcase. Check the oil level and record the vehicle mileage, date, and exact oil level on the form included in this bulletin. Next ensure the oil level is at, but not above, the full mark on the dipstick. add oil if necessary. Also ensure the proper viscosity and quality oil are being used as recommended in the Owner Manual Ask the customer once they have consumed 100 gallons of fuel schedule an appointment and return to the dealer for inspection. If the final evaluation shows that the engine uses more than 0.946 liter (1 qt) in 379 liters (100 gallons) of fuel used, follow the published symptom diagnostics as described in the appropriate Service Manual. If the oil consumption test shows that the engine uses less than 0.946 liter (1 qt) in 379 liters (100 gallons) of fuel used, explain to the customer that their engine meets the guidelines for oil consumption.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...