Stiffen your Mazda 3 rear engine mount - for $4

[flyrevs]

Stiffen your Mazda 3, Speed 3 rear engine mount - for $4

I just got a CB Mazdaspeed 3 and there is a bunch of wheel hop and excessive engine movement caused by the rear engine mount design.
I read all of the posts on how to fix this by spending $90 and replacing it with the AWR mount with urethane bushings. I took the rear engine mount off to examine it and discovered that the main reason it is so bouncy is because it is only partially filled with rubber.

Engineered slop: (circled in red):

Before I shelled out $90 for the AWR I thought I would fill the gap and see how it performed. I bought a tube of 2 part - 6 minute epoxy from Lowes for $4. This stuff has a rated strength of 1900 psi so it will definitely hold up.

2 part 6 Min epoxy - Lowes $4:

I put tape on the back side of the mount to contain the epoxy. I mixed the entire tube of epoxy and poured it into the mount. 1 tube of this is all you need. It flows just right and entirely filled the gap. In about 3 hours it is rock hard (let it setup in a heated area). I installed the engine mount and took it out for a spin.
WOW!!! All the wheel hop is gone, the shifts are now "crisp". Best of all: NO engine vibrations. One thing to note is that when you first start the engine, there is a small short thump, that comes from the engine mount. It's not a big deal just something I thought I would mention. Someone else also described noise this in another thread after putting in a high performance engine mount.
There is no reason now for me to buy the AWR mount, at least I can't think of any. For $4 this is a great mod. I believe you could do this on the Mazda 3 as well.

STEP BY STEP:
0. remove mount from car
1. first tape the bottom of the mount completely with duck tape.
2. put mount on flat surface on a piece of cardboard
3.find a small container to mix it up in (a lid from a can of spray paint works great), squirt it all in and mix well.
4. pour the mixed epoxy in immediately after it is mixed (you have a few minutes before it starts to setup)
5. fill the mount all the way up with the epoxy
6. keep the epoxy out of where the bolt goes !
7. wait until very hard (about 3 hours)
8. remove tape
9. remount the mount in your car
10. tightened all bolts nice and tight
11. drive car - enjoy

One other thought: For those of you who think the epoxy wont give enough, the stock rear engine mount has enough rubber all the way around the center bolt that there is enough "give" to allow some movement of the mount. Also the stock rubber is softer than the urethane high performance mount, the epoxy just cements the whole thing together and gets rid of that pesky air gap in the mount.

 

[Tengo]

i read on another thread that there might be a recall on the motor mounts and that they will swap out the 3's mounts and put the 6's mounts on since i guess they are bigger.

 

[keleko]

i read on another thread that there might be a recall on the motor mounts and that they will swap out the 3's mounts and put the 6's mounts on since i guess they are bigger.

very interesting, as i think mine may have a problem

 

[II-Savy]

Any thought to using a silcone / outside caulk you could use? It woul dkeep the rubber feel and still fill it up.

 

[flyrevs]

Any thought to using a silcone / outside caulk you could use? It woul dkeep the rubber feel and still fill it up.

Doubt if it would hold up very long. The epoxy I used is 1900 psi - pretty tuff stuff. Anyhow I'm real happy with it, it feels great.

 

[protegeV]

I've seen a lot of people use this technique on other cars with semi-solid mounts and it seems to work very well overall. Good job

 

[RevLimitLaunch]

best thing is 3m windshield urethane. pick up a 12 or 16 oz tube (cant remember) for 10 bucks at autozone. i used it on to fill all my mounts on my 93 talon and it works more than perfect. got rid of a lot of problems since my mounts went to s*** but i didnt have money for the energy suspension mounts. 20 bucks total and an afternoon and my car feal crisp after. the epoxy is a good idea too. but for an alternative i believe the urethane may have a little play in it but will definitley hold up no problem. it did on mine for a year.

 

[ZoomVT]

any more info on that possible motor mount recall for mazda 3?

 

[Olestra]

any more info on that possible motor mount recall for mazda 3?

+1 If mazda will put in better motor mounts for me without me having to do a thing, I'd be very happy.

 

[nonopr]

Do you have pictures of the finished product?

IF you can of course?

Doubt if it would hold up very long. The epoxy I used is 1900 psi - pretty tuff stuff. Anyhow I'm real happy with it, it feels great.

 

[benzo]

I asked the dealership about the recall and of course they know nothing yet. I'll keep asking.

 

[bbrich57]

I believe what you are all referring to as a recall is actually one of two TSB's issued about the third engine mount. First issued 7/13/05 and titled Engine Vibration / No. 3 Engine Mount Rubber Broken. http://www.finishlineperformance.com/mazda3/docs/0030.pdf
The second was issued 7/21/06 and is titled Body Vibration at Cruise Speed.
http://www.finishlineperformance.com/mazda3/docs/0049.pdf
According to my research, there are currently no recalls or TSB's specifically concerning the MS3. There was ever only one recall on the 3 series and it was for '04 models and concerned the front crash sensor.

 

[benzo]

Okidoki, I just performed the mod. I used super glue's plastic epoxy. It dried super fast and worked awesome. I do have that slight thump when you first start the car. I can totally tell the difference. I hope to hell that the fill in works for a long time. The mod is super easy to do, and the throttle response is instantanious.

 

[knowledge007]

I just installed my AWR 88 and it feels great... although the car does shake during the first mili seconds of launch but eveything is great. You feel the car's engine really sturdy. Almost all wheel hop is gone. I don't remember the thread that was asking about my mount but their it is. I might, im not sure, but i might call AWR and get the 70 durometer instead, but for now I am going to try it out for the w/e.

 

[bbrich57]

I just installed my AWR 88 and it feels great... although the car does shake during the first mili seconds of launch but eveything is great. You feel the car's engine really sturdy. Almost all wheel hop is gone. I don't remember the thread that was asking about my mount but their it is. I might, im not sure, but i might call AWR and get the 70 durometer instead, but for now I am going to try it out for the w/e.

OUCH!!! You installed the 88... for the STREET?? I say again, OUCH!! That one is meant more for drag racing than for a street car.
My 70 is buzzy enough. It solved the vib @ speed problem I've had since day one, but now the car vibrates @ idle. It's a bit annoying but I don't plan to change back anytime soon either. As you say, take off is smoother and more positive.
Besides, I kinda' like the car being a little less civilized. (laugh)

For those that haven't seen/don't know the differences I took a picture...

​

 

[elderlycoffee]

this voids the warranty if they find out rihgt?

 

[clos561]

this voids the warranty if they find out rihgt?

no

 

[jweidler_1130]

Any manufacturer that wants to void the warrenty for any after-market work that you have done to the car has to prove (legally) that the after-market work caused the issue that you are having. For example, if you install an after-market CAI (cold air intake) and then you have problems with your electric window motor, they are totally unrelated and this would not affect your warrenty for a defective window motor.

However, if you installed a CAI (for example) and you did it incorrectly and there was damage to the engine due to dust particles and debrie getting in the engine, then you may have screwed yourself.

However, with installing your own engine mounts you need to be careful. If there is damage to the engine due to an after-market engine mount failure that causes your engine to fall or tweak, then you might be in for a battle with the dealership.

Question: I don't have an MS3 yet, but am seriously considering purchasing one in July '07. Would you let this issue affect your decision to buy the car? Is there anything I can ask the dealer to do prior to owning the car?

It sounds like there is really no TSB out, which would require the dealer to fix the engine mounts prior to them failing on you.

 

[SPEED305]

what does the number stand for? 80? 88? 70? thanks

 

[Yamaha72]

The numbers are the durometer ratings, the higher the number the stiffer it is.