J-MON

Greetings:

I bought my 8' approx 2 weeks ago and have just been in pure exctasy - However, on Saturday after I got my front brakes serviced at the dealership I bought if from and then drove it to Select Mazda on Centennial Parkway (in Hamilton) for her first oil change (even though sticker on car said I had until August and another 3000km to go). I have the oil change done and meet "Rod" who happens to be fellow rotorhead and head of service there. and all is good and I'm on way home.

So everything is great until I'm 95% home (10 minute drive from dealer) and I go over a bump on my street that I've gone over before in my 8' without incident except this time I heard a loud heavy CLUNK or CLANK sound seemed to come from my back end. FYI - I constantly drive with the windows down (and sunroof) because i think the aural experience is one of the best parts to driving the RX8. In fact I am so in tune with my cars sounds that when I did have litre of 5w-20 in the trunk I could hear it bounce around during semi-hard cornering.

Later that night I went out and drove for about 8-10 minutes and it seemed like every other bump I'd go over would cause the heavy CLUNK / CLANK sound..... loud enough for people to hear on sidewalk say 30-40 feet away very distressing .... it took the wind right out of my sails. The sound seems worse when I go over actual breaks or drops in the pavement as opposed to rolling bumps. The rolling bumps make a very normal "Bump - Bump" sound as the car goes over - which use to be the case for all bumps even the severe ones before this problem would just make a louder "BUMP - BUMP" as the suspension would feel rigid going over but never give off the sound I am hearing now.

Gets more interesting - upon talking to some fellow gear heads they mentioned the obvious "Do you having anything in your trunk ?" No nothing at all that could make that sound. But upon checking just to be sure I thought I had solved the problem !!! I was soooo happy to find a loose " I-BOLT" in my tire change kit (which I noticed didn't seem to be closed properly) - probably one of the service guys went in to find my wheel lock and presto knocked the " I-BOLT" loose. The part was so heavy and it would have been making intermittent contact with the jack I thought I really had found it. OK ..... excellent and on to her first Mother's Stage 3 polish (pics included)

BUT - Tragedy struck again when I went out for a little boot after spending 4-5 hours and 75% of a Bottle of Mother's finest Caranuba wax I heard the sound again ... and AGAIN and AGAIN.. CRIPES !!!!!!!!!!!! + I'm sure it's getting worse.

P.S. I've did a semi-extensive search for related problems on RX8club.com (I do not have a spare tire just the inflation kit) and only came up with a guy having similar problem after he changed to coil over shocks and didnt 'mount' them properly and another Pakistani gentlemen who mentioned a similar problem and people's advice were to check for broken parts (rear end sway bar etc.) in the rear end when it's up on a hoist which it is scheduled for tomorrow at 5pm. I'll keep everyone apprised.

Wish me luck and pray for a gentle $ outcome everybody please.

J-MON

rx8thunder

I had a clunking sound like you describe and was driving me Nuts! Turns out it was a missing bolt on a rear caliper. Check for that...

J-MON

Thanks for this tip Thunder - and a VERY cogent one at that considering I did just have my brakes serviced at the same shop that I'm hoisting it at tomorrow so we'll definitely check all bolts on rear calipers.

shaunv74

Check the DIYs on sway bar installs and spring installs. These have pictures of properly installed components. The only thing I can think of if your spare tire and tire change kit are secure is sway bar installed improperly or broken endlink on your swaybar.

That's very unlikely unless you have installed aftermarket sway bars though.

J-MON

My 8' is 100% stock (so far).

Again the sound is a very heavy metal on metal clank / clunk and sounds like something is loose and is getting looser.

Rod the head of service dept. at Select Mazda on Centennial Parkway in Hamilton said he thinks it could be related to the exhaust in some way ?

Gyro_Bot

Yeah, I've got the same thing. It's mostly the driver rear wheel, and again just as you described, its mostly noticeable over sudden drops, not speed bumps.

To me it sounds like someone left a tool set in my trunk, sounds like a tool chest shaking /bouncing.
Does your car's ride height seem lower? my driver rear is lower than normal. The shocks and springs were checked out... nothing broken. Sway bars look good on mine too.

You know, it might be the exhaust or the brakes, like was mentioned above.
Thank you for starting this thread!

rx8thunder

^ exactly like my situation. Check caliper bolts

Snrub

If the sound occured after taking the car to the dealer, why not take it back?

Can you feel the clunk when it occurs? If so one possibility might be a differential mount.

J-MON

We are totally 1000% in the same boat Gyro <---- I noticed my driver side rear quarter seemed like 1/2 inch lower but I thought that's how the car just sat on my inclined driveway. They say misery loves company...in this case I hope it's only so that we can help each other out of this pit of despair.

I'm headed to the dealer I bought it from in a couple of hours. FINGERS CROSSED everybody.

J-MON

Was your 8's driver side rear hanging low too Thunder ?

rx8thunder

^ No it wasn't

J-MON

OK I just got back from my 'initial' hoist inspection <----- I say initial because it was just my friend and I looking and pulling and tugging on everything to find what could be loose while the 8' was up on the hoist. First thing we checked was the brake caliper bolts and the brakes themselves and they were 100% solid. We did find two components that were loose however. In hindsight I wish I had taken pictures of them because now that I am looking for diagrams / blueprints for the RX-8 so I can spell out the specific component I can't find it. I cannot even find a general picture of the bottom of the RX-8 so i could highlight it.

#$%#%# just tried lookin again and tried takin pic of car from ground as it sits in garage to no avail.

I'll try to explain. This component is as long as your index finger and is only on the driver side front and rear. When I looked for the duplicate / mirror parts on passenger side it does not exist. <STOP THE PRESSES> I realize I sound like an idiot so I redoubled my efforts and took the pics you see attached. Can anyone identify them by sight ? Why are they only on driver side ? Are they redundant ?

That's the only thing we could find that could give off a rattling / clunking sound over 'some' bumps. Seems to only be affected by actual 90 degree drops or increases in the pavement as it handles regular gradual 'raised' bumps without the sound.

Tomorrow it goes into Select Mazda (Hamilton) on Centennial Parkway at 10am. If it's the parts I identified in the picture(s) it cannot be that expensive to replace / repair I'm hoping. I'll keep everyone apprised.

Take Care,

J-MON

rotarygreg

J-mon, the parts you have circled are the sensors for the auto leveling headlights. There is always play in this part, even from new. there is virtually no load on them, they are just disigned to ride with your lower control arms (front and rear) and adjust the headlights accordingly to keep them level with the road. They shouldnt be making any sort of audible clunking noise. I've got my money on rear sway bar endlinks. you might really have to put some muscle into them to feel if they are loose at all.

J-MON

Thanks for this RotaryGreg - you've saved me from sounding like an idiot tomorrow morning when I see "Rod" head of service at Select Mazda and would have proudly proclaimed I most likely found the problem and they shouldn't even bother wasting their time looking for anything else wrong on the car <-------- insert teeth sparkle scene

I think instead of forwarding my novice and clearly innacurate opinion regarding the solution I'll mainly shut my mouth and let the experts take over at Select Mazda - I may however add that some Rx8 enthusiasts that were kind enough to review my problem online mentioned they believe it very well may be rear sway bar endlinks

rotarygreg

well the endlinks are just a guess. basically there arent many parts on the rx8s rear suspension that break or wear out normally. theres swaybar endlinks and bushings. and i've seen a few shock absorbers actually go as well. thats about it. Im sure select will get to the bottom of this though. Also, youve just got the car, correct? if its not still under the factory warranty, most used dealerships offer a 30 or 60 day warranty on every car they sell. usually a small (50-200) deductable and they will cover the rest. so make sure once the cause is found out, you contact them if its an expensive item.

J-MON

Ok my 8' is now at Select Mazda under the careful supervision of a fellow rotorhead 'Rod' head service Mgr there so I know I'm in good hands.

While I was there I noticed a copper red Shinka up on the hoist & i asked about it. Rod mentioned the guy is in for a $2100 repair. WOWIE KAZOWIE ! Apparently the guy has a hole in his gas tank. $1300 for part and 5-6 hours labor ... they actually have to remove the rear diff. to get at it ! I asked if the guy mentioned how it happened ? And all they said was he must have hit something. Ouch

Well fingers crossed, prayers to the Rotary gods for a gentle $ outcome for me and my 8'

J-MON

J-MON

I was really looking forward to putting this problem behind me today, however, my 2nd worse fear in regards to my current 'clunking / clanking' sound problem has just been realized ! The service tech took it out and couldn't hear the problem. When they put it up on the hoist everything checked out. If I had the time this morning I would have gone for the inspection ride with him and stayed while they hoisted the car - but my 11 month comes first so I left it with them.

Now I have to scramble to find a babysitter so I can have Mazda come out and pick me up at the house tomorrow morning (service tech left for the rest of the day today) and then go out on an inspection ride with him so we can isolate the sound I'm hearing.

P.S. I don't know if it's just me but now that I have a full tank of gas (as opposed to the 1/4 or less I was driving around with) I don't notice the problem as much myself.

Stay tuned,

J-MON

Gyro_Bot

I currently have my car on axel jacks to releave pressure on my rear springs, by lifting my rear tires off the ground.

I did this quick test last week, and I noticed the sound became reduced.... probably because ride hieght improved .... because of the fact that if you decompress your springs by raising your car, the result is when you lower your car back down onto your wheels, the springs and shocks stand taller.

Kind of like giving them a refresh... or a chiropractic adjustment.

Starting within the same hour you lower your car back onto it's rear wheels, the springs start to slowly decompress again as you driver over bumps (I HATE NEW WESTMINSTER). However, the refresh adjustment seems to have kept up until Tuesday.... when, I decided to leave my car on axel jacks until the weekend. (Giving my springs 4 days of rest!)

Sigh... maybe it's time to by new coil overs.

J-MON

*Important note: The sound has reduced in intensity by at least 30 - 50% and is livable <--- only thing that has changed is I put a full tank of gas in it. Curious. I can degrade it from a clunk or clank to a rattle...and everyone agrees it's a metal on metal sound and that hasn't changed.

When I showed up today and talked to "Rod" Service manager at Select Mazda he tells me he had a guy go out in my car yesterday AND a different guy go out in my car today and neither of them heard my "problem". I think the word to describe my mood at this point was nonplussed. I see the car pull my car out of the bay and I hop out and meet Jean a service tech at Select. Before we venture out for a drive in my car I mention that I'm sure it's only lateral / horizontal movement within my suspension that is causing the clunk / clank as I can take graduated bumps (railroad tracks, manhole covers etc.) without problem at all. It's a sudden 90 degree increase or decrease (even 1/2 inch) that seems to cause the reaction and only on the driver side.

I hop in the driver seat & Jean in the passenger and we're off. Within 2 minutes - literally - 2 minutes from the dealership he had heard the sound enough times that I asked if we could go back and he agreed. BUT because they saw nothing on the hoist inspection and admittedly couldn't emulate the same conditions in the real world when it was on the hoist nothing can be isolated as the pure cause at this point. Their advice was to bring it back when it is worse or becomes worse.

So that is where I'm at right now. I did discover that if I'm doing 50 km/hr or more and go over a bump that causes the problem it's like a "rattle-rattle-rattle" if go over same bump going 80 km/hr it's a "rattle-rat..." You think this 'condition' will buy me any leeway with the cops ifthey catch me speeding ? Didn't think so. Well this thread may grow a little stale now as I attempt to live with said problem / condition.

My last question is this; has anyone had or heard of failed heat shields or heat shield mounts around the exhaust or cats ? What about loose gas tank strap(s) ?

Take care,

J-MON

9krpmrx8

iTrader: (46)

I will be your savior. I bet money the nuts on the tops of the rear shocks are lose. Does it sound like somthing is rattling around in your rear deck? I tried everything before I just decided to pull the rear shocks and the left rear nut was almost off and the right was very lose. Tightened everything up and all was good.

J-MON

That's exactly how I can describe the sound. Metal on metal rattle around my rear driver quarter >

I sincerely appreciate this tip - I'm going to try it.

How long did it take you to pull the rear shocks ? Does it have to be fully hoisted or can I use jack stands in my garage ?

Thanks again KRPMRX8

9krpmrx8

iTrader: (46)

I just used jack stands. It should take an hour or two. Just check Robin Yang's DIY. I can email it to you if you want.

J-MON

Found the problem today. Everybody ready ? <Drum roll please> ....................................

FRONT BRAKE SLIDER (Driver side)

When the auto technician (same one that did my brake service) at the dealership I bought the car from drove my 8' today he came back after 5 minutes, hoisted the car, and identified the problem. He replicated the god awful rattle sound I hear by hitting the bottom of my front driver side tire with a rubber mallet - THAT'S IT - I exclaimed. He then held the front caliper in place and repeated the exercise - sans noise ! He also mentioned that when he drove the car he noticed that when he applied the brakes lightly the rattle was gone going over road bumps that had previously caused the rattle when he didn't brake.

So I was totally off base stating the sound was coming from the rear. But was correct stating it was from driver side at least.

Part is on order from Mazda as of tomorrow morning. Hoping to get it installed for Friday at the latest.

mat128

Do you have a part number for the brake slider? Can't find it in the collision manual.

I'm having the same problem so that might be it! I also thought (still think tho) that it's coming from the rear. Will try with the brakes slightly on!!

Thanks

9krpmrx8

iTrader: (46)

Weird. And you thought it was coming from the rear? It pays to have a good mechanic, most just replace **** until the eventually get it.

Offtopic, I picked up my bosses AMG S55 from the dealer and he had the spark plugs replaced and it was over $700.00 for 16 plugs.