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Shaking from engine bay

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Old 06-12-10, 09:10 AM
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Shaking from engine bay

Hi everybody,

I need your help since I am not so sure what's up with my 7...

It's a '90 Turbo II manual.

when I accelerate without gear in, I can feel the body of the car shaking. If I accelerate WITH clutch pressed, the car shakes a little bit less than if I leave clutch unpressed.Also seems to shake more in 2nd or 4th gear while moving, 1st,3rd,5th gear shake less but still shake.

I think it's the engine or gearbox mounts that failed on my car. I need someone to show me the points those are, since I got the FSM manual from the net, but I am unable to see the mounts in my engine bay or on the gearbox...

Sorry to be noob but I would like some kind of photo of the mounts looked from above or below the engine bay.
Old 06-12-10, 10:28 AM
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Engine, Not Motor

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Yes, it does sound like mounts. You will find the engine mounts in line with the shock towers. Just look straight down in that area. The left side is on a little steel frame that connects to the side of the center iron. The right side connects to an aluminum arm which bolts to the center iron through the oil pan.

The transmission mount is easy to find. It is at the tail end of the transmission on a crossmember.

At the same time, check your driveshaft u-joints.
Old 06-17-10, 02:53 AM
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I got the car lifted, and a NON rotary friendly mechanic to check all around the mounts, on engine, transmission and differential: he said that the mounts are OK, and I saw myselft at least the engine ones actually are good...

Now, since I am reading a lot of driveshaft U joint failing... how to check those?

And besides, I found searching a couple threads for U-joint spares, but the threads are all more than 3 yrs old...and most end up buying a complete driveshaft wich is crazy to ship over to eurpe so I keep it last resort..
Anyone knows if there is any way to get those U joints spare parts nowadays?

I'll try to be more specific on the shaking problem : the car shakes when moving, on stop it "waves" like it would follow a engine rotation, in fact it moves (standing IN driver's seat) from left to right when accelerating and from right to left decelerating...just like it try to turn with the engine??? And does this a little less when clutch is pressed and gear is IN...without clutch and on neutral, it shakes a lot more..

Also, I had my clutch DISC changed around 35k km ago...but I think we reused the other old parts since those seemed ok at that moment... Could it be something clutch related? I do NOT have any big problem with pedal stickyness or anything weird, and I can step on it even at high RPMs, it's always fuid and not difficult to move or press ...while I know for sure I have worn syncros expecially 2nd and 5th gears ones...My gearbox shifter lever is ok, no play whatsoever...Since I had some difficulties with 2nd gear, I had almost always rev-matched the downshifts, trying to help the gearbox to fit the gears in...
Old 06-17-10, 03:08 AM
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I think I have these symptoms:

Rattling/grinding noise when stopped, engine idling, transmission in gear, clutch pedal on the floor. Pilot bearing is bad if noise stops soon after transmission is put into neutral.
Rattling/grinding noise when stopped, engine idling, transmission in neutral, clutch pedal on the floor. Throw-out bearing is bad if noise stops soon after clutch pedal is let up. Bearings are worn out if noise gets worse when pedal is let up.

Vibration in drivetrain when starting off in first gear, and decreases once car is moving. Front U-joint is bad.
Vibration in drivetrain that gets considerably worse the faster you go. Rear U-joint is bad.
Now, how reliable is http://mazdatrix.com/g2.htm this page?

And more than rattling / grinding, I feel the forum-widespread "whirling" from the transmission...and it got BETTER (or just is covered up maybe ) from the moment these vibrations started?? WTF?

Thanks (Aaron and ) for anyone that reads all and take time to suggest anything to try.
Old 06-17-10, 09:57 AM
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Engine, Not Motor

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It sounds as through there is a balance problem with the engine. Does it move around in the engine bay while running?

Checking the u-joints is easy: Grab the driveshaft and try to rip it off of the car. Any movement side to side means that joints are worn. A local driveline shop should be able to replace the joints or make you a new shaft.
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