Re: #5 cyl. I-5 typically has a problem=clogged exhaust manifold?

[Brendan Rudack <rudack@umcc.ais.org>]

On Tue, 13 Oct 1998, Nathan Belo wrote:

> I heard a rumor that the #5 cylinder typically doesn't get enough air and
> runs lean.  Is this true and would that explain the clogged exhaust
> manifold?  

On the 5ktq #5 tends to lean out causing a hotter "burn" and longterm
problems when running high boost.  It leans out because of the intake
manifold design (not ideal).  More air gets shoved into # 5 because the TB
is at the front of the IM shoving air towards # 5 intake runner.

On your car 90Q 10v #5 would run rich and # 1 would tend to lean out
though not nearly as big a deal as the turbo application.  Again, this is
because of the IM design and having the TB at the back of the manifold.
Truthfully, I can't really see this happening all that much  b/c the air
is being drawn
in under vacuum, therefore it can be distributed more evenly where as the
turbo car the air is getting forced in.  Pulling my NG apart at 130k I did
not see this buildup in #5 EM runner...  An interesting phenomenon
nonetheless.  Might want to check the flow of your injectors.


Brendan Rudack AKA "Bendy"
'98 A4tq 
'88 90q 2B tq pro-rally ride
Fenton, Michigan
USA