[s-cars] 1.8t coils -- new information

[Varon H. Fugman]

First off, Happy New Year!

 

Second, a big thanks to everyone that responded to my 1.8t coil saga posting
a few days ago.  The collective knowledge and experience on this list is
invaluable.

 

Before reverting to OEM-type coils, I figured I try the 1.8t's one more time
(mostly trying doing the spicing needed to replace an OEM coil-I know not
that hard of job, but it would have been a lot easier if Audi had made it
plug-and-play.)

 

I put in the second replacement 1.8t coil (sourced from local VW dealer) and
went for a drive on some nice roads with plenty of opportunity for WOT.  Car
ran smooth and strong.  It hasn't run this well under full boost since
before my OEM coil began to fail.  (Outside temps under 40F don't hurt,
either!)

 

Part way through my drive I stopped for some Shell 93 and during my
underhood check I noticed a lot of heat coming off the 034-sourced coils.
more than seemed to be coming off the dealer-sourced coils.  Humm.

 

Got home, grabbed my IR thermometer, and discovered that the 034-sourced
coils were between 205F and 211F, but the dealer-sourced coils were only
175F to 181F!  That's a 30 degree difference in operating temperature!!!

 

I'm pointing the IR thermometer straight down at the head of each coil,
which I'm guessing contains the POS circuit.  Of course, I'm just measuring
the temperature of the plastic case. no way of knowing the internal
temperature.

 

I'm going to swap the coils around to different cylinders and check
temperatures again tomorrow, but the consistent temperature difference seems
to be indicating a difference in the operating characteristics of the
034-sourced coils and the VW-sourced coils.  And in this case I'm pretty
sure that "hotter" is not "better".

 

Varon

'95 urS6 with 1.8t coils this week, who knows next week?