Tat..Tat Noise in Engine

[DeWitt Harrison]

On Mon, 3 Jul 2006 19:27:38 -0400
        "Max Hoepli" <mhoepli at vif.com> wrote:

> I have a MC engine in Type 44 Quattro, with turbo charger
> with 285,000 km. when idling it makes a tat...tat....tat......tat
> .......tat...noise from top part of engine. When inside of car noise
> is not heard. Engine never overheats, starts immediately.
> Sometimes there is white smoke coming out of exhaust just
> after starting. I alternately fill tank with RON 89 and 91.
> What could problem be?...if any? Gasoline may be issue.
> Could Rislone additive help?

When my lifters stick, they can definitely be heard inside the
cabin. When my MC1 tat....tats as you describe, it's typically
due to an exhaust manifold leak. The following items can
cause this: loose manifold nut(s), broken stud(s) or crack(s)
in the manifold itself. All of these ills are common with the
MC1 e.m. due to poor design. Audi modified the e.m. with the
MC2 engine to correct this problem area by breaking the e.m.
into two sections.

If this tat....tat goes away with engine warmup or continuous
use, then I think the lifter diagnosis may be the right one. If
not, then look closely at the exhaust manifold.

DeWitt Harrison
'88 5kcstq