Car vibrates badly idling in drive?

Question

My car shakes when I have it idling in drive, and a little bit when idling in reverse. It is not throwing any codes for the EGR ISC or TPS, and I just replaced my PCV valve. I also ran seafoam through my motor to get the old grime and oil deposits out trying to stop it, and it only helped out a little. I checked my motor mounts, and the front and rears are in bad shape, so I am going to fill them with 3M Windo-Weld, would that fix it, or is there anything else I can try? Thanks!

Answer 1

As with any diagnosis, we need what kind of car you have, engine size, model year, etc.  Every car is different.  What affects one car may not affect another.  

Edit to additional info:

You probably need to have the valves adjusted.  I looked on the mitsubishi tech site and they want the valves adjusted every 50,000 miles.   Hondas are notorious for that same complaint.  Adjusting the valve lash smooths out the idle just like it came from the factory.

Answer 2

MOTOR MOUNTS??? You have an automatic. It's the motor running at low rpms merely rumbling. try changing your transmission fluid.

All it is though, is your transmission causing friction and bogging down the motor. Any engine -ANY- will shake and tremble at low rpms. You can change your engine mounts and that'll eliminate a very small amount of the rattle. But the problem lies withing the driveline, not engine mounts?? haha, change your tranny fluid make sure the cars running when you put the new stuff in for an acurate reading...

Answer 3

If your motor mounts are wasted window weld wont fix them...get new ones and see if that affects your rough idle...any further diagnosis will require year make model motor etc...Good Luck

Answer 4

Change the motor mounts then...3M makes some good products,but none are made to hold an engine from flying out the hood of a car.This stuff is for glass aplications...You should do a commercial for the product if it works   ;)