RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   3rd Generation Specific (1993-2002) (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/)
-   -   WTF is shaking under my car! (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/wtf-shaking-under-my-car-39508/)

jasonsr1 12-17-01 08:24 PM

WTF is shaking under my car!
 
I'm posting this again because I still haven't found where the noise is coming from. I have a rattling/clanking sound coming from somewhere under my FD. When the engine and other components are cold the sound is much more evident. My neighbor heard it when I was pulling out of the garage and suggested that it came from the front. When I ease the clutch out and proceed at avery low rpm the clanking sound is quite loud. You know when you take off at a low rpm the clutch chatters and everything shakes. Well that's when the clanking is most obvious. However the sound occurs over speed bumps or most other significant bump(s). When everything warms up, the clanking/rattling sound diminishes significantly. I went underneath the car and shook the hell out of the exhaust system (factory), banging on heat shields, just about everything but could not replicate the noise.
Could I have cracked engine mount(s), a broken suspensiion component or dameged sway bar mount ( I will be checking the sway bar next).

Any suggestions would be well appreciated!:hf:

Flybye 12-17-01 08:32 PM

There is a metal plate right on the bellhousing which prevents dirt and other stuff from getting within the clutch area. This plate is removable to be able to inspect the clutch without bringing down the tranny.

Check that plate. It may be loose, but YES, it COULD be a bushing. Did you also check around the tranny bushings?

jasonsr1 12-17-01 08:38 PM

The tranny bushings and/or mounts sounds very plausable because the noise is "heavy" sounding, if you know what I mean, not like a light weight plate shaking around.

Thanks for that suggestion.

Flybye 12-17-01 08:41 PM

If its a heavy thump, it COULD be a bushing.

If you release the clutch quickly, does it make the thump? That amount of force is usually enough to make the entire drivetrain move.

Another thing you could try, is jack up the FD and put it on jackstands, get in and engage the clutch with the engine on, and have someone to the side doing a visual on the drivetrain to see how it's moving around.

jasonsr1 12-17-01 08:59 PM

If I give it enough gas while engaging the clutch, to prevent any chatter or shaking, noise is absent. Only when the drive train is shaking will the clanking happen. Yea apparently significant force is generated during the shaking. Since my ability to reproduce the sound by shaking things under the car was ineffective. That's why I was thinking somenthing with a lot of mass, is moving in an unconstrained fashion.

jr 12-17-01 10:49 PM

I've never heard what it sounds like, but your symptoms sound similar to one's described by another forum member when his Power Plant Frame was cracked. Do a search here in the 3rd gen section on PPF and see if you can find the thread.

2-Rotor 12-18-01 02:04 AM

make sure the inside core of your muffler or cat hasnt shifted that will rattle like hell. Grab both sides and shake or tap it with your fist and see if anything rattles around.

2-Rotor 12-18-01 02:06 AM

also check all your exhaust brackets and bushings

Dragon 12-18-01 05:56 AM

Sounds like the power plant frame... I've seen 3 of them broken... usually it will crack about half way threw towards the tranny side and then flex and hit stuff, also check to see if some of the bolts haven't come loose where it bolts to the tail housing on the tranny...

One way to check it is to dump it and if you hear a loud smacking sound as it hits the lower body you'll know thats what it is for sure..

Hyperite 12-18-01 07:27 AM

Yep, sounds like PPF to me. Take a look, i'll bet it's cracked...especially if you do a lot of "spirited" driving and track events.
~Tom

tschangrx7 12-18-01 08:24 AM

Honey Comb Filter
 
Honey Comb Filter inside my stock catalytic converter got loose and rattled, and until I had a mechanic look at it, I had no clue. Had it replaced with a N-Tech High Flow, no more rattling noise + noticeable increase in HP.

jasonsr1 12-24-01 03:02 AM

I'm 95% certain the noise is coming from the engine mounts. I shook the motor and the sound occured. The harder I shook the louder the clanking/scraping sound. I suppose I need to replace the bushings. Are there stiffer after market bushings available?

Dragueur 12-24-01 10:53 AM

.......................rattling....
 
WHEN you find OUT..can you PLEASE post what was WRONG with it...cause my 95 is doin the SAME shiet!!!!!:( :mad:

NewbernD 12-24-01 11:05 AM

U joints
 
A friend of mine had a very similar problem with his jeep.. it would rattle like hell when there was no load on the diff, especially as it warms up in the morning.. turned out to be some really ratty u joints on the driveshaft.

Dragon 12-24-01 12:06 PM

Unless your pushing 380+ hp, just put in new stock mounts and get an engine tork brace. Also it's probably just the left mount that is bad. It gets pulled appart by the engine torking.. the right side get's smashed so it usually doesn't go bad.. Also check all the stupid heat shiels around the turbo, maybe one has come loose and is hitting somthing...

What part of the car is the noise comming from? near the tranny, right side of the engine, left side, etc...?

the_saint 12-24-01 01:25 PM

You can shake your motor? Hmm I can't barely move my motor. Sounds like you have bad mounts. A torque reaction strut brace will also help. Although I am not sure of the long term consequences of one. They make a huge difference though.

Mike

jasonsr1 12-24-01 03:23 PM

Dragon

It's tuff to pin point the origin of the sound bu it appears to be coming from the drivers side but like I said I'm not certain.

jasonsr1 12-24-01 03:32 PM

I just shook the engine again and sounds like its coming from the passenger side.

jasonsr1 12-24-01 03:34 PM

Any suggestions on how to lift engine enought to remove mounts, excluding hoist. Do you think it's safe to jack under the tranny?

the_saint 12-24-01 03:57 PM

I would not jack up the engine by lifting at the tranny. I would not know any other way of lifting the engine without a hoist.

Mike

Dragon 12-25-01 11:48 PM

Put a 2x4 under the oil pan and lift the engine with a jack, or use a tranny jack, but only put enough pressure on it to lift the engine, DO NOT LIFT THE WHOLE CAR LIKE THIS... make sure your remove the 14mm engine mount bolts first...

jasonsr1 12-26-01 12:05 AM

I like that suggestion, the 2x4 spanning across the oil pan should distribute the weight effectively, preventing denting.

Dragon 12-26-01 01:04 AM

Yep, I've don't it manny times on many diffrent cars, 0 dents to date...
:bigeyes:

jasonsr1 12-28-01 08:19 PM

I believe the right engine mount (passenger side) is most susceptible to damage due the fact that it is located on the "hot" side of the engine.

Dragon 12-29-01 12:38 AM

I've only seen one right side one broke, there are several layers of heat sheild between the turbo and the mount, One of then is actually bolted to the mount... Heat isn't a problem there..


All times are GMT -5. The time now is 11:05 AM.


© 2024 MH Sub I, LLC dba Internet Brands