Bad Engine Mount, Vibrating badly!

[Belial88]

So about a year ago, had some light vibrating/noise, was a front engine mount issue, replaced for like $300.

Suddenly, car went from just fine to vibrating badly, much worse than last time. Like I could tell the second 'it' happened. Thought it may have been an oil change issue, they say its either something, or the engine mount, so im pretty sure its engine mount again.

Its really bad with the car stopped in drive with foot on the brake, though theres a slight vibration even at high speeds and neutral.

I know there are 3 engine mounts, I think I can identify one, cant find the others. Is this something I could fix on my own or something, maybe its just a loose bolt or something? How can I confirm the issue, and can I fix it myself? If not, how much should the repair cost?

thanks.

 

[Donutz]

If you are buying replacement mounts then yes it is something you can do yourself.

Passenger motor mount is near the top of the engine on the passenger side and is the one that most commonly fails. To check this mount look for oil around or under the mount. You can feel underneath the mount for cracks but you won't always be able to find them by feeling your way around. A flashlight and small mirror will let you see underneath.

The transmission mount is under the battery tray. Remove your airbox plumbing going to the battery box. Disconnect battery and remove. Remove bolts in the bottom of the battery box. Disconnect the ECU and remove the battery box. Remove the bracket that the battery box is mounted on. You will be looking at the top of the transmission mount which is essentially a plate or bracket with a large black square bushing and a bolt that points straight down. Inspect the rubber for cracking. Further you need to look under the plate and see if the tripod that the upper trans mount is bolted to. This could be cracked.

Lastly is the rear motor mount. It is at the bottom rear of the engine just about in the middle and secures the engine to the subframe. Remove the bolts holding the aluminium bracket the looks like a pistol. This part is bolted to the engine block. The. Remove the bolt that goes through the mount upwards in the subframe. You will now be able to pull the mount out of the subframe. Inspect the pistol part for cracks (unlikely). Inspect the rubber in the motor mount. Look for cracks or tears.

I would do the work myself. Basic hand tools a jack and stands and you will be able to remove, inspect, and replace any of these mounts. Be advised that some engine movement can occur when you remove mounts. My advice is to look for DIY how-to threads (many of them out there). They will give you tips on how to get the engine back into position so you can bolt up the mounts.

As for costs, this can vary widely for both parts and labour.

 

[Belial88]

wow, thanks a lot! where should i buy engine mounts from? Would a place like autozone have them, or just ebay?

 

[david330]

onlinemazdaparts.com

rockauto.com

 

[Belial88]

Okay here's some pictures, I think it's the transmission mount that's messed up:

Here's a picture of what I believe is the rear mount, seems mine (really? Is that what you call looking like a pistol?

I felt around, seemed okay. I didn't want anything to come crashing down on me when I was under the car so I didn't mess with it. I'd like to replace it all at once if I have to replace it, but I don't think it needs to be. I mean I could tell the second something 'happened' and the car started to vibrate a bunch.

I'll order the part tonight, I'll have to keep driving my car the next few days until I can do the repair. I'm not exactly sure what to buy:

http://onlinemazdaparts.com/parts/2...leid=1432714&diagram=5417300&diagramCallOut=1
I think it's part #2 here, the left mount?

I did not see it at rockauto. I dont think they have it.

 

[Belial88]

edit: Found the transmission mount on rockauto ~$35, under "transmission". Of course.

So it appears I have a choice of OEM (ie at RA) which is smoother but lasts only ~100K, or some polysuperrubber off ebay, etc, aftermarket that lasts longer but is bumpier. I'll go with stock of course...

edit2: I think I should replace my rear mount too, it isn't expensive, I'm down there already, and they all last only like 100K so I should, right. I've already had 2 fail on me.

I found this video on how to replace the transmission mount:
http://www.youtube.com/watch?v=fBQdhuBXxkw

Pretty straightfoward, pull it out, few bolts, whatever. What is not shown on the video though, is if the car is jacked up or anything. So do I need to jack up the car when adding/removing the transmission mount? I dont even know what the transmission is or looks like (I mean I know it's responsible for shifting gears).

I've also seen how to replace the rear mount - take out that 'pistol' bracket, then pull out mount. I'm just worried about an engine falling on me when I do that, I dont know what needs to be propped up when i do that.

edit3: Okay i hav eno clue about torque wrenches or anything like that...

 

[Belial88]

Actually I think I'm just going to go with replacing the transmission mount. There's no special deal or combined shipping and it'd be cheapest to buy the tranny mount from rockauto, and then every other part from ebay anyways, so if the rear mount breaks, I'll buy it then. Plus, it gets a bit expensive with tranny mount + rear mount frame thing + rear mount all added in.

The rubber on the 'pistol' frame thing looked a bit ragged, like an old rubber brand, but no cracks. The rear mount itself, it looked like the subframe was pushing into it so hard that it sort of pinched or broke a bit of it... hard to explain, but I guess it would be like if you had a round piece of rubber and then put a really heavy metal box on it and the rubber sort of being cut by the pressure/edge...

Anyways, going to replace the tranny mount for now. Thanks so much for the help guys, this would have been insanely expensive at the store. Hopefully I don't do major damage by driving the car and commuting to work the next 2-3 days. If I have to, I can use a different car... but I'd rather not.

 

[Donutz]

Good on you for doing the work man!

Yes, that transmission mount is completely shot. I would suggest not driving the car until you replace it. I would also suggest buying a new bolt from Mazda. The bolt the goes though the rubber into the tripod. They are anywhere from $3 - $8 at the dealership.

Your engine mount bracket is different than mine, but you have correctly identified the pistol bracket. Mine is aluminium.

Your other options are to buy aftermarket mounts, but these are not for everyone. The generally come with loads of vibrations and added noise.

 

[Belial88]

Why does the bolt need to be replaced? mazda... hmm would like an autozone have it? what exactly would it be called? I didnt see it on rockauto.

 

[Donutz]

Best practise is why I would replace the bolt. And some time ago there was a recall for the bolt on the speed 3 so you can get the stronger bolt (I think it's all they carry these days). I change that bolt every time I remove it. That bolt endures quite a fair amount of stress. If you think about it, that bolt is the only thing connecting the transmission to the transmission mount, and the transmission is hanging by the bolt. That said the entire weight of the trans/engine is not on that bolt because the weight is also displaced across the rear mount.

I don't know if you have a manual or automatic, but you can search on Jim Ellis Mazda Parts and find almost any part you need to reference. I would only buy this from a Mazda dealer though.

Here's the bolt on a 2005 manual 2.3L (reference the numbers 9ya02-1431 and 9ya02-1437a). The dealership will know which one you need.

 

[Belial88]

I'm sorry i wasn't clear which car I have in my sig, it's 2006 Mazda 3 touring 2.3L hatchback silver (what a mouthful). I'm pretty sure... i mean there's no 'touring' sticker on it, but I think it's the special-er one. I believe the 'speeds' are higher end mazdas, not what I have. I'm automatic (unfortunately). About 120K on it, I bought it in 2010 with 50K.

So what happens if that bolt breaks? Is that common? I mean I'm not relpacing the bolt, I would have if I was told about this earlier, but otherwise I don't think I'l be back in there until another 100k miles if the tranny mount breaks, or if my rear engine mount breaks (which is probably eventually/soon, i mean first 2 have popped so far).

Right now taking apart car and all, I'm not sure on how to remove that darn air filter block, I didnt realize that was attached. I can't figure it out, all the videos online only talk about replacing the air filter which you dont need to remove the air filter block to do, and all the transmission mount videos dont even mention you need to remove it, i guess they assume you know how to do it. Some of them dont even mention that you have to hold up your engine, wow, that would suck...

I also read someone say something about using a torque wrench on some of the bolts for the mount... i'm not sure about that, as not everyone says that, and need to figure out what settings to use.

 

[Belial88]

Got it fixed! Car is super smooth, good as new!

But now have an issue, wondering if I knocked a cable out:

My rear driver side brake light doesnt work. However, my lights work, ie that light turns up when i turn my lights on (like headlights, although those are in the rear... rear lights?). It appears to be just one bulb, but if it's 2 then yea that's a simple replacement obviously...

My horn works, and the other 2 brake lights work just fine (top and passenger rear). Cruise control works.

Did I knock a cable out? Did a bulb die? What happened?

 

[Donutz]

That's a burnt bulb. I'm not sure by your description if you are saying the the drivers side brake light lights up when the accessory switch is on, but doesn't light up when you apply the brakes. On my 2005 the brake light is a dual filament bulb (I likely have the wrong terminology for this); essentially it is possible for the light to come on with your accessories but not come on when you apply the brake. This has happened to me 3 times since owning my car. The bulbs are fairly cheap; about $10 for two bulbs in my area.

 

[Belial88]

Oh, okay, so basically there is 2 bulbs in that red housing. So am I replacing one of 2 bulbs or this dual-bulb?