Pulled the transmission inspection plate off to peak at the flex plate. Clicking this will make more experts see the question and we will remind you when it gets answered. Might want to be ready for some water spray too with this test. Put the front of the car up on jackstands, take the inspection cover off, turn the crank with a large ratchet and check out all the flexplate boltsturn the crank clockwise at all times. So if you have a knocking noise and an automatic transmission, its a good idea to check the torque converter bolts to see if theyre tight. Slowed to idle and pulled off into a business parking lot. The flex plate is a steel plate that bolts to the rear of the engine and has gear teeth. Notice if the starter has a low, medium or highpitched whine while spinning. Thats why i spent time to really listen deep to your video to really hear what the problem is. I hadnt removed the inspection plate yet to see if i had a broken tq converter bolt or a cracked flex plate. Interesting part now is that the knock is very prominent on any acceleration and constant load.
My chevy started this tick noise out of now where thought about it and yea its the flex plate. As a result, this can cause the flexplate to wobble. In this video i talk about a noise coming between the engine and transmission. If the noise goes away with water flooding the bellhousingthen you have a cracked flex plate. I turned the flexplate by prying with a screwdriver in between the teeth. I did not know this at the time i bought it as it was the first time in a long time owning an automatic, so all of my flexplate and torque converter knowledge have come from the last year of owning the blazer. If the tachometer doesnt move, the cps is probably bad. The reason for the sound involves the flexplates location and its function. The knock occurs at idle when the engine is warm and anytime the engine is under load. If not properly diagnosed it will occur again and often damage to the transmission may follow. Jeep grand cherokee questions is it common for a loose flex plate. This videos shows investigation into tightening the flex plate which i did and the noise came back after a few. If youre foot is out of the accelerator pedal and the car is coasting, there is no knock.
I did not remove the starter and check for loose bolts because i wanted to check with you guys again about that inspection cover. A loose bolt will hollow out the hole, and can cause a crack from the hole toward the middle real hard to see. Check the flex plate flywheel for cracks or loose torque convertor bolts. Chevrolet silverado 1500 questions loud knocking noise 5. Injector knock or cracked flex plate diagnosis w 2009 chevrolet duramax lmm dually. Pull lower pan, check rod movement,or remove bearing cap.
Take the inspection plate off and turn the engine by hand to check the flywheel. I cracked two flexplates on a 350 olds i drove balls out all the time, until i threw away the torque converter and got a good one. The knock sensor is a crucial part of the engine, as detonation is harmful to the engine. A loose manual flywheel will cause a knock, so will a cracked flexplate, and the aforementioned cracked piston skirt, all will cause a knock sounding very similar to a rod. 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. I was told that a small crack in the flexplate could mimic the sound of rod knock or piston slap.
When you crack them out where the converter bolts are, they have a very tinny, almost ringing sound under load, and the cracks are very hard to see. Because the flex plate is an integral part of your cars powertrain, and replacing it involves removing the transmission, a significant amount of labor will be involved. I have not grounded out any plug wires to test for rod knock yet. First check your flywheel bolts,as the noise can be transferred. In neutral, brake on, rev engine slightly and note noise.
When they crack near the crank flange, they sound rodknockish. A cracked flexplate is almost always a sign of other problems. Hey all, just recently picked up a 92 sonoma with a 4. Hope this helps and maybe check out this site for a gift to send a special someone. Symptoms of a cracked flexplate general discussion. The reason for the sound involves the flexplate s location and its function.
Is there anyway to check the flywheel torque converter without pulling the engine. Your just not gonna see everything from peeking through that lower cover. Cracked flexplates arent as rare on these vans as they are on other cars. I checked oil pressure, pulled spark plug boots while truck was running but no. Jeep grand cherokee questions is it common for a loose. Check out these reasons you could be hearing an engine rattling noise and what you can expect for repairs with these engine problems and diagnosis. How to know if a flexplate is warped it still runs. Its possible the rear exhaust manifold or even the crossover pipe cracked and developed a leak. If smoke is escaping from the oil fill hole it is very likely to be piston slap from wear or a broken skirt. Under load the noise is the most pronounced between 2k3k rpm. If you are talking about a flywheel for a manual transmission equipped car, the most obvious symptom of a cracked flywheel is a knock.
It makes a bad vibration at about 2k, but not specifically a rattleknock. Well, 2 flex plates later he figured out what was causing the problem. Apr 18, 2009 i did this and it gave me access to the flexplate. I developed a loud knock at the flexplatetq area i got under there to check for cracks or anything unusual, couldnt see anything, so i unbolted the tq from the flexplate and pushed the tq back, turned the engine on and the knock completely disappeared. And we also have heavyduty and sfiapproved flexplates for highhorsepower, highrpm race applications.
All of the teeth look fine and i cant see any cracks in the flexplate. 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. If you happen to have a manual transmission, this does not apply. Then, it happened loud knock knock knock from the engine. Bad knock on engine people say flex plate on 1979 gmc 350. Loose torque converter bolts and cracked flex plates. If it is the flex plate could be cracked and that too can sound like a rod knock. Excessive crankshaft flange runout or end plate can also cause flexplate cracking.
A lifter going bad will have more of a tap, tap, sound and the noise can be located on the top of the engine. Ok, so i replaced my flexplate 290,000 miles to see if that eliminated the lower end noise in my engine. Noise in my chevrolet silverado sounds like flywheel. There was a slight wobble in the flex plate, due to the distortion from the crack. I believe it is a cracked flexplate because i have a vibration when converter locks. Weve got tough yet affordable flexplates for stock and mildly modified street vehicles. Sometimes you can actually get a little movement of the flywheel just before the torque converter moves. Descriptions of the sound include clanking, chirping and a light knocking. Jeep grand cherokee questions is it common for a loose flex.
When i bought my m1009 it had a cracked flywheel and was making the typical rubbing sound when in reverse. Cracked flexplate on your 1998 ford escort automatic. A loose bolt on a flexplate or a crack between its bolt holes. I had posted a similar question when i first got my vehicle around sep. It makes a bad vibration at about 2k, but not specifically a rattle knock. I packed up and headed inside without being able to crawl under and check the plate. To really check your flex plate youve gotta take it out. Discussion in wrangler tj 19962006 started by krisryanl, may 5. And no, i cannot see anything with the inspection cover off. The failure of this sensor would create a no start condition or would shut the truck off as you were driving.
Discussion in engine topic started by purple81, may 10. My freind who is a mechanic says he is almost certain that its the flywheel. An easy way to diagnose a failed cps is to check for tach movement when you crank the engine over. Those factors ensure that when the engine starts and the driver puts it in drive, the cracked flexplates movement will create a noise. This may occur in worn engines or engine that have been poorly rebuilt. Cracked flexplate on your 1998 ford escort automatic transmission you were wondering if anyone knew.
Looks like there is a access panel to access the bolts that bolt the torque coverter and flywheel together. Apr 10, 2012 if the flex plate is cracked it should make noise like a lower end knock. I have the same kind of knocking noise but i know what the problem is. More severe misalignment can break a flexplate in 15,000 to 30,000 miles.
From what ive gathered, that is the noise of a cracked flexplate. To me it sounded like a mad woodpecker somewhere under the truck. 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. Flex plate of a 2012 dodge grand caravan this is a known problem for these vans, causes an awful metal knocking sound when idling and up to around 1,000 rpm. When you have it in your hands look for a redish powder in a line. The water stabilizes the flex plate and lubes the crack. Sounds like rod knock maintenancerepairs car talk community. 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. I have seen a bunch where motor was pulled for said rod knock and broken flex plate was found. One of the other mechanics i work with forgot to transfer them over to a new tranny on a car once and it came back in 300 miles with a cracked flex plate. If its a rod knock then while listening with your stethoscope pull one plug wire at a time sliding a test light down between the plug wire and boot also works. Well i checked torque converter bolts for loosemess and they were fine no sighns of cracked flex plate what so ever im gonna pop. Start the engine, put in drive, foot on the brake, give it some rpm, does that quiet the noise loose bolts and cracked flex will usually be less noise doing that.
Shut it down and got a tow the rest of the way home. Did a log, no st or lt knock i have a pretty conservative tune. Go to a good engine rebuilder and he will be spot on with a diagnosis. Does cracked flex plate makes nocking noise answers. If its a rod knock the knock will go away when you kill the cylinder. 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. There are tough flexplatesand there are chuck norriscaliber flexplates. Cracked flex plate after it heats up, metal expands, will quiet down slightly. Jun 26, 2008 difference is a flywheel is used for a manual transmission. The problem turned out to be a cracked flex plate which.
A bad flex plate usually has failed due to either damage or wear and tear, so replacement with a new flex plate is the only solution. I was told by several people it could be a cracked flex plate. Near the beginning of the video when the van is idling in gear, that noise you hear that sounds like engine knock or marbles in a tin can is what mine is doing. Those factors ensure that when the engine starts and the driver puts it in drive, the cracked flexplate s movement will create a noise. Proposed the issue was the flex plate rather then the engine. It will sound almost like an engine knock but will be heard. The first signs were visible when i removed the dust cover and turned the engine over.
I would assume it would envolve unbolting trans and moving it back. The sound is very similar to a bad connecting rod and is often misdiagnosed. Slight misalignment may only cause a single flexplate to break in the life of the vehicle. It bolts to the end of the crankshaft and attaches to the torque converter. I thought i had a rod knock, but had perfect oil pressure and the noise sounds. When a flexplate cracks, it often produces a loud knocking noise as it rotates. Feb 05, 2011 i would check and make sure you are not missing the alignment dowells for the bellhousing bolts to the engine. Next day try to start it, sounded like a weak battery or starter but car started.
My engine is vibrating and making a knocking sound at idl. If you have checked for rod knock, checked flywheel, adjusted lifters, and still have the knock, what is left to check. Why is the flywheel making a knocking noise as well as the. Flex plate of a 2012 dodge grand caravan this is a known. Mine cracked between two of the large holes not the bolt holes. The classic and most obvious symptom of a cracked flexplate involves the sound it.
Most of the cracked flexplates ive heard sound worst at idle. Give a guess in the comments section and stay tuned for pt. What can i do to troubleshoot this aside from dropping the trans and inspecting. A rod knock can be made to repeatedly occur by revving the engine to 2,000 rpm and quickly releasing the throttle. Remove the inspection cover from the driver side of the bell housing see if the converter is loose.
Flywheel will cause a jumpjerk when releasing clutch. How to check a knock sensor for continuity it still runs. At idle there is a faint almost rod knock type sound from the torque converter flexplate area. Check the heat shield for any looseness and tighten it if necessary. The other thing that could cause an engine vibration that goes away at times is a loose heat shield on the exhaust system. If you have an automatic transmission, you have a flex plate, and it is a possiblity, and it can be checked without.
It didnt fix the noise but now when i start the truck it. Flex plate may have a pingclang noise when accelerating and decelerating. Come to think of it, its a good idea to also check the flex plate for cracks. I developed a loud knock at the flexplate tq area i got under there to check for cracks or anything unusual, couldnt see anything, so i unbolted the tq from the flexplate and pushed the tq back, turned the engine on and the knock completely disappeared. The flexplate takes the place of the flywheel on automatic transmission vehicles. If it really is the flex plate, thats a lot cheaper than other problems that could cause a bad knock. Oct 17, 2016 sometimes the flex plate could be cracked, making the same sounds and vibrations. Either will give a ticking knocking noise, more so on accel and when cold. Weve had a few forum members get broken flex plates in the last few years. Loud knocking sound from torque converter or flywheel.
Sometimes the flex plate will crack and as a result it can cause noise. The plates usually crack around the crank like the picture shown, but those rusty streaks arent aways there. Check yours if you develop a knock, grind or rattle in the bottom of the engine. Im not getting that weird creaking noise he gets on acceleration.