the knock is pretty deep sounding and sounds as if it is coming from the driver side, in the very back of the engine. If you put the car in park and rev the motor there is no noise. In some cases, the timing belt pulley bearing may be causing the noise. . If your vehicle has rear-wheel drive, with its engine mounted lengthwise, your engine may have a fan clutch to regulate the operation of its engine-mounted cooling fan. It has 106k miles on it. But no My 04 suburban did the same thing and it was 2 of the rubber hangers on the muffler and tailpipe. Discussion Starter · #6 · Jan 6, 2016. As you drive your vehicle, the idler pulley spins with the drive belt. catalytic converter. No hesitation and does not run rough. Worn Out Pulley. I just did a tune up on a 02 Dodge Dakota 3. Car makes a rattling noise like something is loose when you start the car and at times while you drive Where is thermostat located on 2001 chevy tracker Car overheated do to i think low on oil i changed oil month or so ago i thought i put enough oil in vehicle it Hey guys. It sounded like the problem was directly behind the instrument cover. All components I keep in good working order. 350 small block knock at idle rpms. Condition/Concern: Some customers may comment on a rattle noise at idle with the transmission in gear. I had a noticeable injector rattle, engine knocking with mild acceleration. A bad torque converter could be the origin of rattling sound when accelerating at low speed. I have about 350 miles on my '02 Z06. Hello-congrats on your new Trax,the engine has a timing chain,I would check with the dealer,is the idle rough,possibly a heat shield under the car vibrating, is it all the time or just early in the day 1st thing in the morning. Joined Feb 1, 2015. 2013 Chevy Cruze. There does not seem to be a problem except Re: 350 v-8 has miss at idle 11-29-04 10:28 AM - Post# 530375 In response to ranman If your replacement engine is from the mid seventies, you could be losing a lobe on the cam, chevy had a problem those years with it's case hardening process. The Chevy dealer said that it was "normal. Question type: Maintenance & Repair. This is especially pronounced on cars with direct injection. . Same Thing. The best way to minimize both piston slap and valve lifter click is to keep the oil changed on schedule with 5W-30 synthetic, as well as keep it full. Discussion Starter · #1 · Mar 15, 2012. No noise. Dealer affirmed hearing it saying may be injector noise. Over time, this leads to wear and tear of the pulley from repeated use. You may have something as simple as your mixture off a bit for idle, you may also want to check/change your fuel filter as it could be clogged and not providing enough fuel at idle. 18 Posts. One common problem that will cause a rattle at idle is a failing hydraulic valve lifter. I am hoping it's just something loose, but my friend Mike, who has never is it common for these bolts to loosen up over time ?? . it sounds like something is loose or rattling and only at an idle Even though the bolt was tight, the cover was loose at the back and rattle sometimes at idle and certain lower rpms. i could feel it in the floor. #12 · Jul 5, 2020. Asked by Henrycardaropoli67 Sep 05, 2015 at 07:12 AM about the 1979 Chevrolet Camaro. I thought it was in the trans, but i had a new trans built for it and the noise is still there. Re: Vibration and. The AERA Technical Committee offers the following information regarding Lifter Noise And Low Oil Pressure On GM Engines on 1997-2013 GM 4. Valves in my Chevy 350 rattling under load, but not during idle. Could this be a sticky lifter or something more serious? I cranked in a lot of advance on the 350 sbc which resulted in great throttle response. It will do it in park at those rpm's and will only It has a rattle noise at idle, im pretty sure it just does it when its warmed up , no other way to explain it , it def coming from inside the trans, its not real loud buy loud enough to annoy the shit out of me is their a way to tell if the 5th gear nut is loose without removing the transmission. #2 · Jan 2, 2009. once you get above idling rpms, the knocking goes away completely and the engine runs very smooth. The fan clutch can fail and produce a rattling noise. BUT as soon as it's under load (acceleration of the vehicle) it will start rattling at I guess 2500 RPM. No clanking noise at idle really at all,Only if i rev the engine about 2000RPM,But the noise is faint in comparison to when it's in gear and moving. 9 V6. 3 2014 - Silverado makes a clattering noise while running/idling in park. It only happens when the engine is revving down, either during engine braking or off idle. 1,662 Posts. Katie7312 said: I just recently purchased a certified pre-owned 2014 Traverse. An expert who has achieved level 1. ·. replaced them. It's most noticeable at a stop or at low speeds (probably b/c no road noise). Advised to put some more miles on it and then bring it back in. A worn timing chain may make noise inside the casing, especially if it is sitting loosely enough on its gears to rattle. It starts quiet and gets a but louder but not super loud. Whenever i park somewhere and just idle, i hear a graudual rattle. The car is a 1978 Firebird, it has a rebuilt (I have no specs at all) Chevy 350 the previous owner dropped in. Hope this helps. Maintenance/Repairs. Try moving your exhaust, by hand, to see if it touches the plate. Upon removing the cap, I noticed the rotor was loose. Iowan said: I have a 2004 LLY Duramax and its recently started making a rattling noise. When revving the engine up even just a little bit, the noise is no longer heard 2009 2. Does not happen at fast idle during warm up. Within 4 days of purchase it started making an awful, "rattle" noise only after a cold start and had a very rough idle. I recently noticed that there’s a rattling sound when the car in in idle (800RPM) but it disappear when I rev it up to higher RPM or while driving. Slipping Belt. Participant. Not only can this degradation lead to an annoying tapping noise but it can also decrease engine efficiency, and therefore power. #15 · Nov 11, 2013. " "They all do it!" I told him that it was unacceptable and to tell the GM rep that this will be my last Chevy truck. i have a 2006 chevy silverado, 5. It will be a faint sound when the car is idling in ‘park’ mode, but the volume and frequency will increase in proportion to acceleration. However, the A/C system has been completely removed, including the belt that goes around the pulley. Our car has been ticking while idling, and the noise gets louder and faster when accelerating. Newly built Chevy 350 (96-99) "rattling" sound with slight throttle but the idle on the carb is really high right now, and the second start up it was already down Thewholeenchelada. Car makes a rattling noise like something is loose when you start the car and at times while you drive Where is thermostat located on 2001 chevy tracker Car overheated do to i think low on oil i changed oil month or so ago i thought i put enough oil in vehicle it It will occur at idle and increases as you rev the engine, continuing even when the engine is warm. Engine Spark Knock - That Annoying Knocking, Pinging Or Rattling Sound Engine spark knock, sounds like a metallic knocking, pinging or rattling noise, coming from your engine. Greetings people. because my torsion bars wee raised i check the shock bushings. 7L has had the same loud, oil pressure related rattle on startup, from when it was new. If a "cat" has come apart inside, it will create high Hc (hydro carbons) for one and a bad rattle at idle and when initially accelerating. Usually, the noise is most pronounced when the car is idle. are off to one side, probably the passenger side if the setup is like my RX350 that shares the same engine with the ES. I have a 2007 2. To hear this, you will need to open the hood with the engine running and listen closely since it may be inaudible above the general engine noise while you sit in the car. I think the noise is coming from underneath the car and not the engine. 19 Posts. As it ages, the pulley can develop wear marks and scuffs on the surface. I drive a 6-speed manual. The ECM may be loose in the mounting bracket. It is Joined Jul 5, 2020. Temp gets to about 150 or so. I start up the car and let it idle for 3 or 4 minutes. the knock is pretty deep sounding and sounds as if it is I have a pretty fresh 350 in one of our 68's that makes a clacking sound under load. There does not seem to be a problem except Registered. Once that was corrected, no more rattle. The fix: Immediately shut off the engine. Water pump was changed recently due to a This creates a rattling noise. Have a weird question I have a 91' Camaro RS. I've got a crate 350 in my 72 that has given me absolutely no problems during the 30K miles I've put on it. Question: Why does my 2009 Chevy Traverse make a rattling noise when stopped at a light? It seems to be coming from the middle console. This will make the engine just a touch leaner at idle but still retain high manifold vacuum. Engine Rattling Causes: Chevy Silverado. Besides a rattling noise, this will upset timing, preventing valves and pistons synchronization, and loss of engine power. Joined Sep 29, 2013. Out of the blue about a few days ago, my truck started rattling really bad at idle, almost like as if it was on the 12v tune, but it wasnt. Today's vehicles have very complicated valve systems, many with variable valve timing, yet they are often relatively trouble-free. Now with the new one it rattles at idle but stops when RPM is raised. Save Share. Although the idle noise is always quiet (I can actually order in the drive-throughs now), the driving noise is really getting on my nerves. Below is a Video of this sound My 5. If you don’t deal with it, that engine rattling sound will never go away. I put a summit 1104 cam lifters in it new. When It gets fairly low on gasoline there is a part that starts to vibrate horribly causing what sounds to be metal on metal clashing. Put the car up on jack stands and poked around underneath for a few minutes. Its 4x4 if that has anything to do with the issue. 1991 Chevy Camaro Odd rattling noise in engine. I have a 1973 Chevy 350 engine new pistons new rods. My 98 Tahoe makes valve lifter noise when I do a cold start like overnight. Newly built Chevy 350 (96-99) "rattling" sound with slight throttle but the idle on the carb is really high right now, and the second start up it was already down The sound occurs off idle, only in Drive when accelerating/cruising. When the oil level gets too low, there can be a situation where air gets pumped through the engine, along with the reduced amount of oil that remains. 85 Chevy Silverado C10 short, wide, yellow, 2wd. Sounds like bolts bouncing around or popcorn popping. I read in 1 forum (i think not on this website) that this issue might have been coming from the heat shield 1 Posts. Chevy 882 heads redone valves springs retainers locks ect. 88 chevy 1500 350 tbi new plugs and wires and fuel filter. Under the hood, rattling noises suggest the water pump is ready to fail. Only makes the noise at idle. The noise I am hearing sounds like a loud, rattling or grinding noise, but its a deep sound like thicker metal rattling together, not like thin heat shields rattling. If this were to happen, the supercharger may develop a noticeable rattle noise at idle. Seems to do it more once the engine is warm rather than The ES350 has a transverse mounted engine, meaning the accessory belt, alternator, A/C compressor etc. On the driver's side. 86000 miles. 7L & 6. When I give it the throttle quickly it jumps from 1 to 20. Almost like a metal on metal "ting ting" sound. 23 Posts. i've done a search for a rattling / knocking sound from the transmission and it looks like converter or flex plate bolts . 2L engine may exhibit a rattle or rapping type sound during cold operation at light loads and speeds from Idle- 3000 RPM. the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from. Answer: If the noise is coming from under the car, check the exhaust heat shields, sometimes they become rusted and loose, then start to rattle at idle. any ideas or info? Chevy 350 valve lifter noise. As soon as you come off idle, even in neutral, the noise stops. 7 Posts. Im having an issue with my engine on my 1995 Tahoe. GM's solution is to remove the plate. 9. New. What you’ll hear is a clattering, tinny metal noise when you idle. When the timing belt or serpentine belt is ready to go, you probably won’t hear a rattle. e. If I floor the car, you don't really hear it, until I release the gas and then you hear it winding down consistent with the RPM's. I have only heard this noise in Park at Idle and it does not do it all the time. Damaged Pulley. Tapped each cat, no noise. xx each). A classic case of a tappety, rattling engine. 0 liter vortec gasser and it was throwing the P0300 random cylinder misfire code which I think I may have fixed but lately it has been making a rattle noise at 1000-1500 RPM's and only there. #5 · Mar 24, 2010. Discussion Starter · #1 · Mar 23, 2010. I determined that with the PCV valve hooked up, my SBC 350 will not idle right, it just fluctautes up and down. when the engine is cool, there is no knocking, but once it gets warmed up it starts aknockin'. Discussion Starter · #1 · May 2, 2011. It seems to be coming from the middle console. The noise can’t be heard inside the cabin and can only heard outside. I localized the noise and found it's a small cylindrical housing, a 1/2" rubber hose runs into Joined Oct 4, 2007. 85000 miles on the engine, presumably never rebuilt. 40 Gov-lok 12 bolt. July 4, 2016, 7:55pm #1. With the line removed and capped off it sounds great, no RPM fluctuations. Ever since that oil change, the car has been making a very noticeable rattling noise only when my foot is on the gas slightly, and only while moving. M. The rattling noise isn't there when the car is in park. The idle was erratic and misfired. Valve lifter noise is detrimental and should be addressed quickly. The present unit you have is rated for a higher base vacuum signal range. 1. How to Check for Slack in Your Timing Chain Besides diagnosing a rattling noise coming from the front engine cover, you can do the following check. Being able to hear the noise when you hold the brake in gear and throttle it doesn't sound like pinging unless you have some major detonation that is coming on right off idle! When you hold the brake and rev it in gear the engine physically torques over in the mounts compared to free reving, try to eliminate any moving parts hitting stationary parts. i have a chevy 350 small block that knocks at idling rpms. 8L Diesel. Let it warm up. anyone had this problem with a borg warner t56 trans fitted few years ago using a wier hot rods bell housing to a 350 small block with a isky 280 mega cam box sounds real bad at idle box was new when fitted , removed and striped down trans and found nothing wrong rebuilt with new bearings fitted new mcloud clutch ,trans is great to drive and shifts perfect , problem is at idle but as soon as Joined Jan 4, 2010. Discussion Starter · #1 · Jul 11, 2012 (Edited) Prior to my return from vacation (Parker/Havasu) for the 4th. this is what happened to me. Models: 2006-2009 Chevrolet Corvette Equipped with 6L80 (RPO - MYC) Automatic Transmission The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI. to any of you guys that are goin crazy with a front end rattle and can't find it. Go to NAPA and get a #29506 PCV valve which is the cross to a the original AC-Delco #CV769C used on many engines. Cleaning out the oil return holes atop the cylinder heads did not solver the problem (although I'm sure the heads are happy to be relieved of 20+ years of carbon buildup. I can hold the brake in gear and throttle it and it will have the clacking noise. 3l, it has about 92000 miles, it has recently started to make and weird clicking noise and im not sure what it is, the rate of the tappin is consistent with the RPMs, sounds like it could be a piston slap or something hitting something else, any one have any advice on Some 2004-2010 F-150, 2005-2010 F-Super Duty 250/350, 2005-2013 Expedition, Navigator and 2006-2008 Mark LT vehicles equipped with 5. the engine also tends to overheat at high speeds regardless of a good cooling system. its not a consistant rattle but more random and comes and goes whenever it pleases. Likewise, positive crankcase ventilation (PCV) valves can tick or rattle at idle. It lasts for a few seconds, then disappears to reappear a few seconds later. February 6, 2014 at 1:40 pm #573318. couldn't believe that would shake a big truck like that but it did. Sounds almost like something is loose, or a pulley is loose or something, and sometimes when coming to a stop at a red light, it makes a random clunk and rattle noise intermittently. After Chevy had it for 5 days they said it was an issue with the timing chains. The lifters are small parts that open and close the engine valves, activated by oil (hydraulic) pressure. -A few things to note can only be heard from side of truck on inside (very annoying) no recent work/changes were done prior to the noise occuring 3 Posts. My setup is the PCV in the passenger valve cover and a K&N oil breather/filter in the driver's side valve cover. Mine is doing the same thing, only mine doesn't have the CVT. It's amazing how much of that noise transmitted through the firewall and into the cabin. 4l having a problem with balance chain pins that wear and that it Can cause an engine noise. my truck makes a rattling noise at idle, in any gear, at any rpm over 1000 it goes away. And, usually occurs after the engine, has reached or is near normal operating temperature. Some 2016-2017 Mustang GT350 equipped with the 5. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3. Its not a rhythmic knocking or tapping. The noise is also only present on a engine that has been brought to Valve train noises occur at half of crankshaft speed so even if your ear can't tell whether the noise is happening at 700 rpm (raps per minute) or only 350 rpm, your eyes can. Cold or Hot. Noise. The most common engine rattling at idle isn’t an engine problem at all. #2 · Jun 25, 2000. This noise is only noticeable at idle and a slight increase in RPM will diminish the noise. The old PCV valve had a bunch of sludge in it and would not rattle during idle or shaken. Theres is a metalic "tapping " sound while the engine idles. TH350 trans. Discussion Starter · #1 · Mar 28, 2008. Its been making the rattling noise on startup a couple times a week now, and when I changed the oil this last weekend I saw a lot of metal flakes on the inlet of the filter As far as the starter goes, I checked the bolts, Their all tightened down, The truck always fires up almost instantly,Whats strange is the noise really only happens when the truck is put into gear and driven. Bad fan clutch. 1 Posts. An expert that has 1 follower. The shift from neutral to drive occurs at about the 4 second mark of the audio. MP3 Audio Link. 4. I had our 2013 Malibu turbo in last year for a rattle noise. This last July 2013 I received a letter from GM with a notice of some 2010 2. #5 · Nov 14, 2015. today while driving around i started noticing a knocking/rattling sound only at idle in gear "drive" in my camaro and can't figure out what it is . Here are the most common causes of a rattling sound in your Silverado: Exhaust. You may need to sell a car with a blown engine at this point. But when I push on the pedal, it makes the noise. A rattling engine can be caused be the exhaust, timing chain, loose accessories, and much more. When I got done it sounded and idled great. Stops around 900 RPM. Sounds like it is towards the front. 2L V8 engine (LSA), may have a condition where the engine’s supercharger may not function as designed. SSM 46173 – Some 2016-2017 GT350 Mustangs Might Exhibit Piston Rattle From Idle To 3000 RPM. 3L, 5. Oil has been changed regularly. The bulletin is#PIT5505: Rattle Noise Diagnostics with LWN 2. Jeff. Some audio, not very good but shows there is some sort of noise/rattling that occurs when shifting from neutral to drive. Discussion Starter · #6 · Mar 27, 2019. Lifter Noise. Also try some carburator cleaner as you could have some crud in there. A worn down camshaft Discussion Starter · #6 · Mar 27, 2019. Wondering if anybody can help me out. Some 2004-2010 F-150, 2005-2010 F-Super Duty 250/350, 2005-2013 Expedition, Navigator and 2006-2008 Mark LT vehicles equipped with 5. They would compare it to another 2014 running/idling at that time. Second probability, if you have the feeling that the hot engine rattling is related to the combustion of your engine, there are three possible causes of this one. 0L engines. Engine Rattling At Idle Catalytic Converter Problems. Positive changes add vacuum, so shoot for the highest vacuum reading attainable with the engine in Park or Neutral. Logged. #11 · Jul 24, 2014 (Edited) My 2008 Colorado 3. It's a rattle as if something was loose. If this happens, you should take the vehicle to a Whats up guys, Hey I have a 2003 3500HD with the 6. New cap, rotor, plugs, wires, air filter and PCV valve. #9 · Apr 20, 2016. When sitting in the garage and idling, it will gladly take the accelerator right up to WOT, without any audible valve train noise or anything. Let me know what the readings are. I got my 350 running,and ran it the 20 minutes at 2000rpm for the cam breakin,halfway through the break in I started hearing a slight lifter tick so I let it run the whole 20 minutes and then let it idle down and pulled off the valve covers one side at a time and readjusted all of them at idle. It's really been making a lot of noise lately. I recently purchased a 2010 GLK with 25,000 miles. 3 Posts. Once you wore through the "too thin" hard layer, a lobe would wear down real fast. Hello All, I have an older 2001 Honda accord I4 about 160k miles on it. Seems to be coming from the rear of the engine possibly in the turbo area. bearings. This torque tube noise was a common problem with the c6 auto,with the c6 the mettalic rattle was caused by a nut called the hub nut which would come loose and make the hub move on the splines of the flex plate spindle, aluminum is a great amplifier of sound and the bellhousing where the Some 2009-2013 model year Cadillac CTS and 2012-2013 model year Chevrolet Camaro vehicles, equipped with a 6. K. 2L engine may exhibit a rattle or rapping type sound during cold operation at light loads and speeds from Idle-3000 RPM. It does it about once every 2-3 seconds. Its been doing this for the last few days and is consistent. If it's pinging it sounds strange to me, and I have tried changing timing with no luck so far. Rattle noise when car is idle. Also doesn't do it on short trips, after 15-20+ miles of driving it then it will do it. it only happens when my truck is accelerating at low RPMs, usually when driving in parking lots. Solution: Replace the starter motor. 76 Posts. Took out the passenger O2 so both rear O2's were out. Start going and push in my clutch to go to 2nd and when I do, I hear a metal type rattle under my car. Now after about 2 hours of running Im hearing lifter noise 2013 Chevy Cruze. Hook the timing light to any one cylinder and watch the flash illuminate the timing mark. Underhood Rattle Noise Heard On Acceleration (Check A/C System Performance and Compressor Operation) 2003-2004 Cadillac CTS 2002-2004 Cadillac Escalade, Escalade EXT 2003-2004 Cadillac Escalade ESV 2002-2004 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe 2002-2004 GMC Denali, Denali XL, Savana, Sierra, Yukon, Yukon XL Causes of Idler Pulley Noise. It rattles when I idle after driving for a little while, and I've noticed the RPM's drop slightly when it does this for a few seconds, and then after the few seconds it returns to normal, no more rattling and no RPM drop. #3 · Nov 19, 2011. About 2 weeks ago, it began running very poorly. Engine size is 350. I said screw it and went and bought two new rear O2's ($67. For anyone with a rattle concern GM has released a bulletin. As your car ages, the engine can consume, burn, or leak oil. It rattles in direct relation to the engine RPM's. Water pump was changed recently due to a This valve will make a ticking noise at times. If so, idle quality could be slightly worse with the wrong PCV valve as well, may have very slight off-idle hesitation issues too. However, when the engine heats up it is hard to start. I can't remember what the part was called. The fuel injectors on newer vehicles can also be loud and make a ticking noise. I just started noticing a strange rattling type noise which appears to be coming from either midway or the back of the car. The noise is similar to an old typewriter click sound. 13,055 Posts. Discussion Starter · #1 · May 10, 2010. The 2012 Chevrolet Sonic has 5 problems reported for sway bar link rattle. Just got the exhaust on the 350 sbc and now I am hearing a ticking noise from under the valve cover for the first time. I know my 2010 was much quiete 330 Posts. Between shifts you would hear the excessive rattle/knocking but The use of the wrong rating unit will produce increased oil consumption, decreased idle quality and other issues - like 'rattling'. The noise also only appears when it is warmed (engine running for about 3 - 5 minutes after cold start Joined Oct 4, 2007. HEI distributor. My wife said the other day she misses my Duramax, and in regard to the noise while driving, I would have to agree. If you have the NPP exhaust, and the optional "dress up" plate between the exhaust tips, the tips of the NPP will actually hit the plate while at idle or when you hit a bump. The rattle could be part of the failed emmisions test i. The exhaust system is one of the most common culprits that can make it sound like your Chevy Silverado’s engine is rattling. I have a bone stock 350 out of a 74 nova. Discussion Starter · #1 · May 1, 2007. Engine spark knock, is usually heard, during moderate to heavy engine acceleration. My Chevelle makes this rattling noise when I accelerate. 4L 3V engine may exhibit an intermittent rattle noise while driving from idle up to 1200 RPM when the engine is at operating temperature. Shook the O2 sensors, they didn't make much noise. Hello, Im new to the Forum and plan to be on here a good bit. So I back out of my driveway and put it in 1st. Engineering has identified 3 possible areas to inspect for a rattle noise. 8L, 5. Also sounds like i have an old noisy double disc clutch (Thats probably the best way to describe it), But its an automatic lol. Engine has been making a knocking/tapping noise at idle that sounds EXACTLY like in this video ( ) The noise is only heard at idle (750RPM) and goes away if the engine is revved up. Then turn each screw in (lean) about roughly 1/32-inch. It sounds like it is coming from around the crankshaft pulley area. Motor runs fine. Runs and idles fine when parked but has a racing cam when I push down on the gas it wont get up and go like it used to a couple days ago I have to let up on the gas to get it to go but sounds like marbles are in the engine? "A rattling noise while accelerating slowly between 2500-3000 RPM" They got back to me with Special Service Message 46173 that says: "Some 2016-2017 Mustang GT350 equipped with the 5. At 800 rpm, my vacuum fluctuates fairly steadily between 14 and 16. It's not loose and doesn't appear to be damaged. I replaced it but now its doing it again ugh!! The part is below the engine cover on the driver side it is fairly close to the top of the engine and bolts in with three bolts. Average repair cost is $230 at 45,350 miles. I could hear the rattling noise over on the passenger side ever so faint. found that i needed a Cold or Hot. Work carefully and slowly to achieve the best results. melott. Everything was done right and I have a rattle in it. So the TB started making this horrible rattling noise underneath the vehicle the other day. Noise was very noticeable until about 3-4 lbs of boost, then the noise was gone. It could indicate the last stage of the converter’s life. Installed them and the noise is gone. Now, while idling/warming up the engine occasionally a tapping/rattling noise comes from the engine. The engine of my Chevrolet Silverado is doing some rattling noise when hot because of combustion problem. This torque tube noise was a common problem with the c6 auto,with the c6 the mettalic rattle was caused by a nut called the hub nut which would come loose and make the hub move on the splines of the flex plate spindle, aluminum is a great amplifier of sound and the bellhousing where the 2,225 Posts. I have played around with the idle speed and 16 is the most I can get. had a noise in the front end when ever i would go over bumps. This can produce a rattling noise from within the engine. Most PCV valve's weights are marked for loading, might look into the engine port of the valves and see if you can see an ID, either number (s) or letter (s). Registered. It happens very quietly at idle, loudly when first accelerating right after decellerating (like when you first press the pedal after a turn). You can't post conmments that contain an email address. I think I read somewhere this is "normal" with these engines. In my 1992 Chevy Silverado, 5. It doesn't lose power, it just rattles, guite loudly though. I own a 1989 Kawasaki EN-454 LTD. 7L V8, the engine purrs like a kitten if you rev it up in park, but once you're in gear and rolling, the valves rattle like a symphony of little hammers anywhere over 1500 RPMs. Joined Mar 14, 2012.