7ron9

Good morning. My 79 vette has 71k miles. How can I tell if my motor mounts need to be replaced?

7Ron9

bradleyb66

The mount that 'normally' goes bad is the left (driver) side. The easiest way to see if it's broken is to open the hood, put your foot on the brake, and blip the gas pedal a couple of times. If the mount is broken, you'll probably be able to see the motor 'twisting' and rising up on the drivers side. It should be quite noticeable.

Your 79 motor mounts should have metal safety tabs that prevent the motor from flexing too much if the rubber part of the mount breaks.

7ron9

Thank you. Can you place the car in park to observe this twisting/torque motion. What would a bad right mount look like?

bradleyb66

You might be able to see it with the car in park, but I forgot to mention in my above post to put it in drive (obviously, make sure you have some open space in front of you). You should see the motor noticeably 'rise up' then go back down if the left mount is broken. I've never seen a broken right mount, so I'm not sure what that would look like. But the left one is the one with the most torque on it, so it is more likely to break.

Here's a YouTube vid that shows a broken motor mount. The motor in this video does NOT have the metal safety brackets on the mount, so it is moving more than yours will (but will give you a general idea).

Alan 71

Hi b,
The engine mounts are made of 3 pieces… 2 of them steel and 1 of very hard dense rubber.
Look for serious deterioration of the rubber pad as a sign that the mount needs to be replaced.
Regards,
Alan

lvmyvt76

just replace them, if you have doublt, spend money!