I know it dosent have a chain so i took it to a local diesel shop and it turned out to be a bad flex plate probably caused by loose bolts. A rod knock will definitely change on float, you can run this at idle, unloaded, to help diagnosis only. However if it had done that you wouldnt have been able to restart the car because the starter would have nothing to spin the engine with. Think it goes in a little deeper to a bad trans front pump bushing and or a cracked torque converter hub. Pull lower pan,check rod movement,or remove bearing cap. You may also hear the same knock as you would in a flywheel. The trans temp shouldnt have any affect on a cracked or broken flex plate. A cracked flex plate is almost always a sign of other problems. The engineer put a triangular file on it and had no trouble marking the plate, he said it is just plain old mild steel, and welding would be no troubles.
I would assume it would envolve unbolting trans and moving it back. Now obviously subaru boxer engines dont have top and bottom in the classical sense but the meaning is the same, the crank is screwed. If the flex plate is cracked, there will be one solid knock sound when you turn the key back on. The classic and most obvious symptom of a cracked flexplate involves the sound it makes while the engine is running.
Dec 19, 2017 however to my way of thinking, a cracked flexplate wouldnt go away at all. The classic and most obvious symptom of a cracked flexplate involves the sound it. It makes a bad vibration at about 2k, but not specifically a rattleknock. I am getting a pretty loud pinging noise when i go to start it up in.
After they checked it out, they said it was a cracked flex plate between the tranny and engine, and that this is a known issue with gm. It runs fine in park but in any other gear with my foot on the brake it has a very noticeable, almost loud knocking sound. I only say this because it happened to my 2000 and the dealer told me i had an engine knock and that my engine was toast. When i logged it, it pulled timing like crazy thinking it was engine knock, but in. My buddy, when he cracked the converter hub, it pissed a lot of atf when you shut. I pulled the trany today and inspected the flex plate. Customer experienced loud engine noise and our tech found a cracked flex plate from over tightened bolts. Jeep grand cherokee questions is it common for a loose.
Had that on a small block chevy years ago and it sounded like a bad rod knock that would go away when warmed up. Those factors ensure that when the engine starts and the driver puts it in drive, the cracked flexplates movement will create a noise. Register now to gain access to all of our features. At the center of the plate, bolts connect to the crankshaft. I really hope thats what it is, and that the noise will go away when replaced.
More severe misalignment can break a flexplate in 15,000 to 30,000 miles. If you logged it while it was making rattling noise, theres a good chance its not in the flexplate area. Notice if the starter has a low, medium or highpitched whine while spinning. Flexing with engine speed was popping the metal back and forth on the cracks. Loose flywheel or flexplate bolts make a rattling or knocking sound that. How to know if a flexplate is warped by chris stevenson. But with a crack flex plate if you press and hold the brake pedel and step on the gas pedel just a little the noise goes away with a rod knock the noise. The flex plate usually makes a tinny or clanging some times chirping sound while starting,shutting off, accelerating or decelerating. The sound is very similar to a bad engine rod and is often misdiagnosed. With c19, bbs doctors diagnosis was the equivalent of calling his sickness a cracked flex plate when it really was a bad rod knock in a sbc.
To me it sounded like a mad woodpecker somewhere under the truck. I have not grounded out any plug wires to test for rod knock yet. Ok, so i replaced my flexplate 290,000 miles to see if that eliminated the lower end noise in my engine. Not much sound out of the tailpipe, but i did notice the tickknock is loud even behind the truck, stumbled upon some people pointing at their flex plate, will take a look at it tomorrow. Might want to be ready for some water spray too with.
Sometimes the flex plate will crack and as a result it can cause noise. I had what sounds like a similar knock especially noticeable at or near idle. When a flexplate cracks, it often produces a loud knocking noise as it rotates. As i was driving into work this morning i noticed a sound that seemed to come from the middle of the car.
Being an auto, it will be fluid balanced by the torque convertor, so babancing it wont be an issue. Descriptions of the sound include clanking, chirping and a light knocking. Thuroughly check the flexplate for cracks you may have a sound similiar to the one i had that cant be fixed by simply tightening the bolts. When i logged it, it pulled timing like crazy thinking it was engine knock, but in reality it was just a little dowel pin banging around. Mine cracked between two of the large holes not the bolt holes. Chevrolet silverado 1500 questions loud knocking noise 5. What could cause a knocking noise from a subaru engine. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. If you have a knocking noise from your engine it might not be the engine itself. The same things that cause the flexplate to crack can also cause transmission problems. Yesterday the flex plate on my 2000 toyota 4runner w 155k miles was replaced. If its a rod knock, you can make the sound change or go away by pulling off each plug wire one at a time. The reason for the sound involves the flexplate s location and its function.
However to my way of thinking, a cracked flexplate wouldnt go away at all. View from inspection plate back of inspection plate. First check your flywheel bolts,as the noise can be transferred. My chevy started this tick noise out of now where thought about it and yea its the flex plate. Though i never heard about chrysler issuing a better replacement flex plate part. I have the back seats out so there isnt too much sound dampening back there, and i have been listening for any odd noises over the past few weeks. Does cracked flex plate makes nocking noise answers. Im figuring it would make the rod knock sound but would like to here if others have had the same experience with bad welds on the flex plate this is a donor engine for my project car and in anticipation of the flex plate being bad i had ordered a couple of new sfi flex plates from summit two years ago. Im not one on hybrids, dont like them and in my opinion theyre worthless as theyre not really good in any one thing and they rode very rough when compared to a dedicated at tire or highway tire.
Checked inspection plate, no carnage but wasnt able to rotate by hand. What can i do to troubleshoot this aside from dropping the trans and inspecting. Those factors ensure that when the engine starts and the driver puts it in drive, the cracked flexplate s movement will create a noise. In this video i talk about a noise coming between the engine and transmission. My guess would be if its flex plate related is loose torque converter bolts.
Then whom ever replaced the fp before me didnt catch the peened bellhousing and tightened it down causing a alignment problem. More than likely it is just loose flex plate bolts, or the flex plate itself is cracked and thats an entire different beast, and is a pretty simple fix. If you are talking about a flywheel for a manual transmission equipped car, the most obvious symptom of a cracked flywheel is a knock. Fontverdanaim leaning towards a cracked flex plate being the culprit not sure what could have led to a cracked flexplate, but very happy, to say the least, that its not the engine. Following up on my previous question, i have a 97 chevy s10 zr2 4x4 with the 4. It didnt fix the noise but now when i start the truck it. And no, i cannot see anything with the inspection cover off.
Cracked flexplate how can i tell the chrysler minivan. Well i checked torque converter bolts for loosemess and they were fine no sighns of cracked flex plate what so ever im gonna pop off the valve cover as i had it running and drove it up on ramps the knocking noise even under a load could hardley hear it and the longer i had it running the quitter it got that doesnt sound like a rod or main or piston sounds more like a calapsed lifter. Between the connecting rod and the crankshaft, a highpressure film of engine oil, less than half the thickness of a human hair, keeps moving parts from. When i first start up my xj it doesnt make the noise but after a couple of minutes it begins to start knocking, it almost sounds like its coming from the front of engine but once you climb under it you can tell its coming from the flexplate area. I just thought id post a short video of what a cracked flexplate on a 6.
Check yours if you develop a knock, grind or rattle in the bottom of the engine. Symptoms of a cracked flexplate general discussion. Mechanical fuel pump, loose harmonic balancer, loose torque converter and the aforementioned cracked flex plate have been some that i have experienced. Symptoms of a cracked flexplate welcome to modern mopar forum. A loose bolt on a flexplate or a crack between its bolt holes. But when you raised the rpm to a middle level the knock went completely away. Symptoms of a cracked flexplate general discussion modern. If in fact they did, perhaps mine will last longer. The problem turned out to be a cracked flex plate which. What are the likely causes of failure so maybe i wont do it again. Flex plate of a 2012 dodge grand caravan this is a known. Doctors diagnosis equivalent of a rod knock in a sbc but it really was a cracked flex plate. I have seen a bunch where motor was pulled for said rod knock and broken flex plate was found. Mine did this and it turned out that my flexplate was cracked bad.
Im leaning towards a cracked flex plate being the culprit. Mar 03, 2015 in this video i talk about a noise coming between the engine and transmission. This may occur in worn engines or engine that have been poorly rebuilt. Apr 18, 2009 depends where you live and elements you drive in. If you have an automatic transmission, you have a flex plate, and it is a possiblity, and it can be checked without. Loose torque converter bolts and cracked flex plates diagnosing noises in your car ericthecarguy video description. On automatic transmission vehicles, the flex plate connects the engine to the transmission. If it were the flex plate i would think you would hear it all the time or at a certain rpm. Might want to be ready for some water spray too with this test. Right off the bat, they said it didnt sound like piston slap. And probably, some lessthanawesome mechanics might even mistake said noise for an engine knock wristpin knock. My uncle thinks it may be a cracked flex plate from how i described it to him. Does your xj ever knock at idle and go away at higher rpms.
Loose torque converter bolts and cracked flex plates. It all depends mine cracked around the center and sounded just like loose bolts. Start your vehicle as normal, but pay particular attention to the noise of the starter while it spins and engages the flexplate, or torque converter if your vehicle does not have a toothed flex plate. As i start to move the knock speed increases slightly with rpm but then stops and the engine runs fine. If the flex plate is cracked it should make noise like a lower end knock. The first cracked fp for me i ignorantly assumed the missing torque converter bolt was the problem so i missed the bellhousing problem. A rattling noise the behind engine loose flywheel bolts.
Bell housing knocking chevy trailblazer, trailblazer ss and gmc. Pull one plug wire at a time while its running, and if one cylinder has a knock, it will stop or change tone when you pull the plug on the effected cylinder. Come to think of it, its a good idea to also check the flex plate for cracks. Did a log, no st or lt knocki have a pretty conservative tune. I believe it is a cracked flexplate because i have a vibration when converter locks. It will sound almost like an engine knock but will be heard from the area between the front of the transmission and rear of the engine. One clue you might look for based on an experience i had. It didnt fix the noise but now when i start the truck it sounds pretty bad only while the starter is engaged.
Glad he made it through the death knock and yeah, ok. Valve lifter vs cracked flex plate vs rod knock noise. Slight misalignment may only cause a single flexplate to break in the life of the vehicle. It seems the centrifugal force kept the plate from popping as it turned at higher speeds. I was told that a small crack in the flexplate could mimic the sound of rod knock or piston slap. The reason for the sound involves the flexplates location and its function. D2 2002 lower engine knock land rover and range rover forum.
I checked the flex plate, and outside of the tc thru the inspection holes, they dont appear to be obviously damaged or cracked. Jan 27, 2009 is it common for these bolts to loosen up over time ive done a search for a rattling knocking sound from the transmission and it looks like converter or flex plate bolts. How to know if a flexplate is warped it still runs. When you hit the right cylinder with the bad rod bearing the sound will quit or get much. The knock was still there after installing the new flex plate.
Excessive crankshaft flange runout or end plate can also cause flexplate cracking. The water stabilizes the flex plate and lubes the crack. I would bet a dime that you have a cracked or soon cracked flex plate between the flywheel and converter. I have the same kind of knocking noise but i know what the problem is. Does your xj jeep ever knock at idle and go away at higher rpms. The first signs were visible when i removed the dust cover and turned the engine over.
I had posted a similar question when i first got my vehicle around sep. If you happen to have a manual transmission, this does not apply. I hadnt removed the inspection plate yet to see if i had a broken tq converter bolt or a cracked flex plate. I have seen on occasion the torque converter bolts get loose and. Engine spark knock sounds like a metallic knocking. So while youre in there, check the flex plate for cracks or damage, you might just find the source of your noise this way. Proposed the issue was the flex plate rather then the engine.
Furthermore, if not properly diagnosed it will occur again and often damage to the transmission may follow. Sounds like rod knock maintenancerepairs car talk community. Jeep grand cherokee questions is it common for a loose flex. Injector knock or cracked flexplate diagnosis w 2009 chevrolet duramax lmm dually. If the noise goes away with water flooding the bellhousingthen you have a cracked flex plate. I need some help, i,ve had a knock sound coming from my torque converter area for a while. The symptom was a ticking sound under certain conditions. Give a guess in the comments section and stay tuned for pt. The likely cause for the cracked flex plate is likely due to misalignment because of dowel pins that keep. I had a cracked flexplate on my 74 that was a hard knock sound like a rod bearing at idle and low rpm.
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