Since I have transplanted a rebuilt motor into my 1981 rabbit with A/C interior, the increased compression at idle is just rattling everything inside the dash. I tried pushing various locations of the dash with my hand while the car was idling to see if the rattling would stop and it i didn't. Once the car has increased RPM's above idle does the dash rattles stop. I do not want to increase the idle RPM just to stop the dash rattles. I tried to take things apart and reinstall them and made sure that the screws and bolts were nice and tight to reduce the rattles but was unsuccessful. I also have since installed a new stereo deck, but made sure that was nice and secured. Who here has been successful in reducing or eliminating the dash rattles and what methods did you use?
Thanks
With MKI I have owned many, only my 83 GTI didn't have dash rattles.
If you figure it out let me know as the 81 I had I couldn't hardly drive it. The rattles were the main reason I sold it. The only thing I was thinking was taking it all out, putting in a rubber compound of some kind where it contacts, and putting it all back.
Engine mounts may be hard too.
my mk2 is relatively silent in comparison to your guy's stories but i have been meaning to pull the whole dash forward a few inches and stuff some dynamat (or something sound deadening) not only to muffle the engine noise but also to firm things up and stop the rattle.
Speeding up the idle a bit is the best and easiest thing.
You may even actually be too low.
Since its a new engine, you probly already put new engine mounts too. If your hand can't stop any dash noise, check your side windows. The welting on them deteriorates, and they can be just as much a source as anything.
its really easy to go too low on your idle on a VW diesel, they will idle at about 250 rpms..
The #1 cause of dash noise on a MK1 is the passenger side mount. Did you replace it when you swapped the motor? If you used a heavy duty or urethane mount, that's your problem. If not, then an old-degraded mount can cause it too. Check that one primarily, and the others while you're at it.
its really easy to go too low on your idle on a VW diesel, they will idle at about 250 rpms..
HAha yeah i had it as low as it would go one time, man was she bucking! lol