Driveline vibration help - '84 4KQ

[Larry C Leung]

Works for LIttle VW's too. Open hood, set the brake, put the car in gear,
GENTLLLY let out the clutch enough to put a little torque on the engine.
The gear is dependant upon which mount is bad, either 1st or R. It will
be obvious if the mount is broken, it will pick up quite noticably.

LL - NY

On Thu, 17 Jan 2002 07:44:35 -0500 "Doyt W. Echelberger"
<Doyt at nwonline.net> writes:
>On big US V-8's, a bad motor mount will allow the engine to lift
>visibly
>when you blip the throttle from idle. They can jump several inches.
>Might
>apply to Audi's.
>
>Open the hood in good light. Have someone blip the throttle while you
>stand
>at the SIDE of the car and watch the engine movement. Don't get run
>over by
>standing in front of the car.
>
>As mentioned above, this test works well on big US V8's. The engine
>may
>rise 2-3 inches and drop back down with a resounding thump. They will
>even
>rap the underside of the hood when tested with the hood closed.  I
>never
>tried it on an in-line 5 Audi with bad mounts.   I've had two I-5's
>but
>they have good mounts. However, the theory is valid, and may be
>revealing.
>
>The above advice is only a partial answer. If your car has original
>mounts,
>the ones that get the most heat and oil contamination will probably
>need
>replacement and have probably been failing for several years. If you
>are
>guessing, pick the ones most likely.
>
>I swapped mine when I changed engines in the 86 4kq. They were bad,
>consistent with the degree that they had been abused by heat, oil, and
>age.
>
>Doyt Echelberger
>
>
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>At 06:27 AM 1/17/2002 -0500, you wrote:
>>Hi all,
>>
>>I hope someone out there has a good method for diagnosing a bad motor
>
>>mount or transmission mount.  I get a pronounced vibration all
>throughout
>>the car especially in 5th gear at highway speed (65mph and up).  When
>I
>>put the clutch in at speed, the vibration goes away.  This is why I
>>believe it to be a motor/transmission mount problem.  Also, in 1st or
>2nd
>>gear, when I let off the throttle at 3K-4K rpm while still in gear, I
>get
>>an occasional clunk.
>>
>>Thanks in advance.
>>Carl
>
>