Flywheel Flex Plate

[ArnZ!]

hey fellas

Does anyone know what a cracked flex plate would sound like. I had the auto transmission rebuilt and they replaced the TC with a rebuilt/new one so that should be fine. I hear this ticking noise from there and it only ever happens when i idle. When im driving theres no noise.

Im sure the noise isnt an exhaust leak (checked everywhere), i had my valves adjusted (2,000kms ago), i have new penrite HPR30 oil in there which is nice and thick.

Im positive that the noise is coming from the the TC area because i used a garden pipe to listen around and the noise comes loudest from the peak hole.

Ive searched on around and no one has had the same issue.

Heres a video of the noise

http://www.youtube.com/watch?v=_D1Z9tbKdxA

[whiskychaser]

hey fellas

Does anyone know what a cracked flex plate would sound like. I had the auto transmission rebuilt and they replaced the TC with a rebuilt/new one so that should be fine. I hear this ticking noise from there and it only ever happens when i idle. When im driving theres no noise.

Im sure the noise isnt an exhaust leak (checked everywhere), i had my valves adjusted (2,000kms ago), i have new penrite HPR30 oil in there which is nice and thick.

Im positive that the noise is coming from the the TC area because i used a garden pipe to listen around and the noise comes loudest from the peak hole.

Ive searched on around and no one has had the same issue.

Heres a video of the noise

http://www.youtube.com/watch?v=_D1Z9tbKdxA

I'm guessing you have HPR30 in the engine. The gearbox oil would be Dexron III and I wouldnt say thats thick. I doubt the flex plate is cracked, but if it were, wouldnt it make the noise all the time? There was a post on here about a clicking caused by loose engine to transmission bolts. I'd be tempted to give them a quick check. Maybe the TC to flex plate bolts too. If that didnt turn up anything I'd be round to the shop that did the work PDQ

[ArnZ!]

I'm guessing you have HPR30 in the engine. The gearbox oil would be Dexron III and I wouldnt say thats thick. I doubt the flex plate is cracked, but if it were, wouldnt it make the noise all the time? There was a post on here about a clicking caused by loose engine to transmission bolts. I'd be tempted to give them a quick check. Maybe the TC to flex plate bolts too. If that didnt turn up anything I'd be round to the shop that did the work PDQ

HPR30 oil in the engine. and yes the autobox oil is dexron 3

Tomoz im gonna go see if those bolts are tight.

[whiskychaser]

Here's the thread I meant. Knew it was around somewhere:

http://www.bimmernut.com/forum/showthread.php?t=11568

[ArnZ!]

Here's the thread I meant. Knew it was around somewhere:

http://www.bimmernut.com/forum/showthread.php?t=11568

thanks for that

i tried to find it before to no avail.

i doubt that is my problem because it certainly looks to be mated well with the engine. plus my problem only happens when upto operating temp.

[SnakeyesTx]

I've broken many MANY flexplates on various 4x4's and a few cars. Basically the sound of one of those going is strikingly similar to the sound of a thrown rod bearing. Very loud, very deep, ALWAYS knocking, and speeds up with engine speed. Generally they crack right around the base where the flexplate meets the crank. Most manufacturers press the flange out a little bit and that edge is where the weak-spot is. You'll know when you break it too! :D

You'll be moving forward then all of a sudden you've got the worlds most responsive throttle and you can rev the motor from 1k-6k almost instantly every time you press the pedal since the motor is no longer dragged down by the rest of the drivetrain and you slowly coast to a stop >_<




hey fellas

Does anyone know what a cracked flex plate would sound like. I had the auto transmission rebuilt and they replaced the TC with a rebuilt/new one so that should be fine. I hear this ticking noise from there and it only ever happens when i idle. When im driving theres no noise.

Im sure the noise isnt an exhaust leak (checked everywhere), i had my valves adjusted (2,000kms ago), i have new penrite HPR30 oil in there which is nice and thick.

Im positive that the noise is coming from the the TC area because i used a garden pipe to listen around and the noise comes loudest from the peak hole.

Ive searched on around and no one has had the same issue.

Heres a video of the noise

http://www.youtube.com/watch?v=_D1Z9tbKdxA

[632 Regal]

Doesn't sound like a flex plate but it is coming from the area. Take a peek in there, should be obvious if something is loose or cracked. Sounds like it only makes the noise during deccelerating opposed to putting a load on it. no clue whats up with the underline thing

[Blitzkrieg Bob]

the shop forgot to torque down the TC bolts.

[bubba966]

the shop forgot to torque down the TC bolts.

I'd guess that as well.

I've had TC bolts come loose and the sound was intermittant like yours is. I've also cracked a flex plate at the TC bolt holes before and recall it being more of a constant noise than a loose TC bolt.

Is there anyway to look at the flex plate w/out dropping your tranny? I know it's plenty easy to inspect the flex plate & TC on my '79 C20. But that's a bit different than a 535. Haven't bothered to take a look at that yet on my M-Sport, but I'm sure it's not like a 535 either.

[ArnZ!]

Yeah theres are peak hole in the oil pan of the m30, take the plastic cover off and you then have access to the bolts.

Going to double check them now actually, ill report back later.

[ArnZ!]

UPDATE: TC bolts were tight. I snugged them up a bit more and no difference.

[632 Regal]

the only thing I can thing transmission related besides a cracked flex plate is the trans pump... I think it is time to take it back and complain. Sounds like loose rocker arms but wouldnt go away under load... too strange man.

[ArnZ!]

UPDATE:

I just took my car to the shop who rebuilt it and he reckons its one of my engine bearings or tappets..........this is when i had a wtf look on my face as according to him its not the transmission.

I then took the car to my mechanic who does some work on the car. I told him to chuck the car up on his hoist and have a listen. He reckon no way in the world is that rod knock or engine bearings. Then we used a garden hose and had a listen around. If you point the hose towards the engine in the bellhousing peak hole you hear nothing. If you point it towards the transmission side you hear the tick tick tick. So my mechanic reckons its the transmission.

So now i took my car around to another auto transmission shop to get there opinion but sadly there were fully booked so i have to go there tomoz morning. Im interested to hear what their opinion is.

[632 Regal]

my guess is they tightened the trans to the engine before the torque converter was in place and busted the ring on the input pump and just squeezed them together thus messing the pump up... these guys wouldn't pass back alley requirements.

Let me know how wrong i am.

[ArnZ!]

my guess is they tightened the trans to the engine before the torque converter was in place and busted the ring on the input pump and just squeezed them together thus messing the pump up... these guys wouldn't pass back alley requirements.

Let me know how wrong i am.

well if that happens i dont think the pump would last 500kms not to mention there would be some sort of leak i would imagine. mind you all driveability is fine. Forwards gears work good, reverse works good, just a noisy tick tick tick at idle upto operating temp.

Sometimes i think im going crazy as i do loose sleep over noises like that.....

[ArnZ!]

Okay new update

The other transmission shop i went to this morning said its not the engine or transmission but could be the flex plate..... so once again im left guessing.

Maybe my oil pressure at idle is low......

i dunno..... im over it..........

[632 Regal]

man it really does sound like the rockers are loose or the lifters are not filling.... and you say this is only til it is warm which leads me to the idea that your oil pressure is low when cold or not flowing til warm. Too thick oil? Too thin?

This is like a dog chasing its tail because the sound seems to be coming from the bottom. what about with the hood open is there any clatter up there too?

I am baffled.

[ArnZ!]

I had 15w40 in there before which was fine. Noise still existed.
Last week i put in some 20w60 semi-syn oil and the noise is still there.
Both weight of oil are good for the climate i live in.

Up top the engine noise is the usual m30 sewing machine sound. Valves like i said were adjusted just recently and had quieted down the valves a bit. You can hear the injectors ticking away too but they have a different tick. Then under all those noises you can still hear the annoying ticking coming from down low.

i wonder why the noise doesn't happen when cold though.... when cold you would hear rockers/rod knock/piston slap/etc a lot more right? Then when the engine is warm expansion of the metals help make those noises disappear and not to mention that the oil is thinner and able to pumped around better.......

The noise is somehow amplified i the bellhousing. Its the only place where you can hear it from. Ive stuck a screwdriver/hose everywhere on the engine block and theres no ticking from the engine. Ive done the same to the transmission. Both dont re-produce the same noise from the bell housing.....

btw if i did have low oil pressure wouldnt the idiot light come on or flicker?

Could this be my case?
http://i254.photobucket.com/albums/hh89/arnzlozz/bearing.jpg

[Blitzkrieg Bob]

Did anyone check the torque on the TC bolts?

[ArnZ!]

Did anyone check the torque on the TC bolts?

Yep mate, myself and the workshop who did the transmission.