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Engine Vibration 1990 Corolla

by wavjumpr, December 23, 2009 in Pre-1997 Toyota Corolla and Geo Prizm



I have a 1990 tyoyota corolla with 121,00 org miles, i have a vibration when I put the vehicle in drive, not so much when in park, just say if I am sitting at a light. Now if I turn the ac on that helps, minimize the shaking. I know there are 4 engine mounts on the engine and this shaking is only noticable when sitting at a light in drive, 2 of the engine mounts have been changed, the one in the front near the radiator and the one on the passager side on the fender well. The other 2 the one on the passenger side aft of the engine and the one under the air filter box have not been changed, do you think this might be causing the problem. Transmission shifts normal, and engine runs great.

Thanks..

also how easy is it to change the front struts, everything else on the car has been replaced, timing belt,hoses, all belts, battery...

Struts are pretty straight forward to replace - you'll need some equipment to compress the spring to get the struts out and a decent sized breaker bar to loosen the strut bolts.

As for the shaking, could be a number of things. Given the age and mileage - motor mounts would be my first guess. If it is due to the remaining, unchanged mounts, that is hard to say. Try jacking up one of the front corners of the car - don't need to lift a tire in the air, just enough to chassis a bit. See if the vibration changes. If you have a good floor jack, try lifting the engine slightly, enough to unload some of the mounts - you can lift from the oil pan, make sure you place some scrap wood between the jack head and the pan. You shouldn't put too much strain on the the pan - as you aren't trying to lift the car in the air - basically just barely holding the engine up. See if the vibration changes.

If the vibration changes in any of those cases, probably a good chance the other motor mounts need to be replaced. They are really tough to check visually, unless the mount is completely deteriorated. There is a chance that one of the replacement mounts is faulty - hopefully that is not the case here.

But since you mentioned that the shaking is less if the idle speed gets bumped up (AC kicked on when in gear) - there is a chance that your engines just needs a comprehesive tune up. Before you spend money on the mounts - trying getting a tune up. If you haven't had a tune up recently, now owuld be a good time to get one. Check plugs, plug wires, distributor cap and rotor. Check for vacuum leaks, fluid/filter change, clean/replace PCV valve, clean the throttle body. Also verify that the timing is within spec - if the timing is off or idle speed too low - you'll experience excessive engine vibration.

Struts are pretty straight forward to replace - you'll need some equipment to compress the spring to get the struts out and a decent sized breaker bar to loosen the strut bolts.

 

As for the shaking, could be a number of things. Given the age and mileage - motor mounts would be my first guess. If it is due to the remaining, unchanged mounts, that is hard to say. Try jacking up one of the front corners of the car - don't need to lift a tire in the air, just enough to chassis a bit. See if the vibration changes. If you have a good floor jack, try lifting the engine slightly, enough to unload some of the mounts - you can lift from the oil pan, make sure you place some scrap wood between the jack head and the pan. You shouldn't put too much strain on the the pan - as you aren't trying to lift the car in the air - basically just barely holding the engine up. See if the vibration changes.

If the vibration changes in any of those cases, probably a good chance the other motor mounts need to be replaced. They are really tough to check visually, unless the mount is completely deteriorated. There is a chance that one of the replacement mounts is faulty - hopefully that is not the case here.

But since you mentioned that the shaking is less if the idle speed gets bumped up (AC kicked on when in gear) - there is a chance that your engines just needs a comprehesive tune up. Before you spend money on the mounts - trying getting a tune up. If you haven't had a tune up recently, now owuld be a good time to get one. Check plugs, plug wires, distributor cap and rotor. Check for vacuum leaks, fluid/filter change, clean/replace PCV valve, clean the throttle body. Also verify that the timing is within spec - if the timing is off or idle speed too low - you'll experience excessive engine vibration.

Thank you I changed the driver side mount under the air cleaner, seemed to help alot. something I can easily live with. One thing though, when I was taking off the two bolts under the mount One bold head busted off so I had to use a high speed cutter to cut the nut off, luckily I have a good air compressor. Next is the struts, I have the tool to compress the springs..



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