atl8

iTrader: (1)

Is your 8 having issues with vibration at idle?

I had a new right (passenger-side) engine mount installed on my car today. I was told by the mechanic at my dealership that there is a known issue with this mount that a tech support bulletin had recently been released on. He said according to the notice it was affecting cars at approximately 18,000 to 25,000 miles and was caused on the passenger side only because of the close proximity of the mount to the exhaust ports on that side of the engine. The problem can be seen if you remove the wheel and pull back the rubber splash gaurd and inspect the top portion of the engine mount for cracks. If you have the problem you would notice the car vibrating at idle. The problem was not noticeable once you have the car above 1500 RPM and where moving. The new part number for the updated mount is F151-39-040C. The original was 39-040.

khoney

That's interesting. I have a vibration problem at idle that is very annoying, especially when the A/C compressor kicks on. I don't see a TSB posted for it yet, so thanks for the heads-up. I'm taking my car in soon, and now I have one more thing they can check. How's your vibration problem since the mount was replaced? Mine is always worse after the car has been running a long time.

snap-on

There is a new mount..with varied results.

The new one has a heat shield to protect the mount from the exhaust.

If your vibration is more noticable now then when you bought the car this may be for you.

khoney

Well, I pulled my wheel to try to look at the engine mount. I could not pry the boot up with a screwdriver - it was almost like it was glued, and I didn't want to be accused of 'ruining it' by the dealership. Anyway, watching the mount with a flashlight during idle, I was getting about 1/8" of travel. I didn't jack up the driver's side to see if it was the same, but I'm betting it's not.

brillo

interesting. I don't see a tsb on finishline performance, but this is good to know. Maybe snap on has more info? Atl8 has this helped?

zoom44

there is no tsb but there is an "mri" its one step below a tsb. what snap-on said is abouty all there is to know. some vibrations have been found to be caused by a broken motor mount. the new version has a heat shield.

Marietta 8

Glad my buds were able to help out! Wording gets it done everytime. Mines over there right now getting all the goods.

Charlie

brillo

out of curiousity, I took my right wheel off and checked the mount as best I could. I fired up the car and watched and I didn't see anything that looked like a crack, and while I could feel the vibration, it wasn't huge. I did find it interesting that the subframe where the mount is attached didn't seem to vibrate at all, yet the brake caliper on the wheel you could feel the vibration from the engine. I'm guessing that the subframe is mounted in such a way that its to stiff to move much, while the wheel and brakes would be the exact opposite.

The little rubber splash guard atl8 is refering too is not on the engine mount, it hangs vertically near the brake lines. The cracks would be visible on the mount without moving anything.

RX8-TX

.....not that I am freaking out or anything, just out of plain curiosity....would anyone have a photo of where to look. Yes...I know :o but I am a very graphic oriented person. :p

Tamas

iTrader: (1)

Yeah, a photo would be great.
I'm wondering if a heat shield could be installed to the original motor mount to prevent it from cracking...

whenson417

Thanks need to go out to Charlie (Marietta8) for informing me about this and other issues that need to be updated when I was at his shop the other day. I dropped my car off yesterday to have this procedure done with hopes of getting it back today but we will see. I guess it is a pretty big issue they are having because the sevice manager told me that Mazda was sending them the motor mounts via fedex overnight which is not very common.

Go48

It's not that uncommon for the dealers to order overnight delivery of parts. When I need parts that are not in stock, they always ask if I need it tomorrow.

atl8

iTrader: (1)

pictures as requested. one w/ splash shield on, 2nd with it pulled away. 3rd is a not quite focused close-up. The piece with the yellow dot is the new heat shield.

What I've noticed with the mount replaced is no more vibration felt by my hands on the steering wheel. Before the car would shudder every 10-15 seconds or so and I'd notice it there.

RX8-TX

Hats-off to you!

Tamas

iTrader: (1)

Interesting... that doesn't really look like a heat shield but like a bracket or clamp to make it tight.

atl8

iTrader: (1)

Ya know. Methinks Tamas is correct. I just jacked up the driver side on my car and inspected it's motor mount and it looks exactly the same as the new one that was just installed. I even crawled underneath the car and looked at the new mount from the engine side. I don't see anything that looks like a heat shield to me. Also, the mechanic at Mazda didn't mention it had that, someone in this thread said that and I ASSumed it was the case. Regardless, it has helped with the vibration I was experiencing at idle, and for that I need to thank Charlie at Mazcare for pointing me to someone that was really helpful at my dealership's service department.

silver bullet 53

I have been having the exact problem and been driving 2 of my local dealers nuts with it! just so happens my car is there today so I just called them to check that out for me and they had absolutly no clue or info about the issue. They are going to check it anyway, but at least they won't tell me it's just the computer" breakin in" anymore! I will repost when I get the car back tonight, But awesome info....Thanks :D

khoney

My 9/30/03 build engine mount looks just like the one in your picture, except I have more than one yellow dot. I'm still gonne try to get it replaced on my next service.

silver bullet 53

Just got an answer back from my dealer today, and they confirmed that my passenger side mount is cracked!!! This rough idle/vibration thing has been driving me nuts, I have had the same symptoms as everyone else in this thread and the dealer kept telling me it will smooth out when the computer breaks in????
The big difference on my 8 is that it only has 7,000 miles on it.

Just as a tip to everyone else, if you have a rough idle/vibration tell your dealer about this, because as in my case they had no clue and were very curiuos as to how I even knew about it!
Big thanks to atl8, snap-on and all else on this thread, you have saved me from trading back my beloved 8 :D

TeamRX8

iTrader: (25)

my '05 came with the new motor mounts installed

brillo

bump

snap-on

The parts system shows the mounts have been modified 3 times.

F151-39-040C (HP)
F151-39-050C (SP)

The latest mount should have a heat shield to protect the rubber from the exhaust heat.

brillo

I sat in a 05 and let it warm up, I could feel the vibration, just not as much as mine. I wonder if that car had these mounts, I would guess not, prolly one of them in between the original and this new design.

snap-on

Without the build date it would be had to tell. The new mount shows the latest revision in Jan 05.

brillo

VIN: JM1FE173150151406 - Thats what I tested