Having problems with your 1992 Mercury Sable ?
When going over 40 mph the car will down shift from overdrive and the rmps will jump to 3,000. Fluid is good. I can hear a vacuum leak from the drivers side.
You need to find the vacuum leak, this could be the problem. It may be a hose that is dry rotted or cracked and will be hard to see. You can sometimes spray a mixture of water and soap to find the bad hose. It should not be to hard since you know that the sound is coming from the driver side. Feel and grab around the hoses and slide your hand down to feel for any sucking air.
Repair Help & Product Troubleshooting for 1992 Mercury Sable
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