Old Library

Coil Pack Repair/Reinforcement for VR6's:

Part I - Background

1)  What is a coil pack?  Thanks for asking.  The coil pack replaces
distributor caps on "new and improved" ignition system.  Instead of having a
rotor and distributor cap "distribute" the ignition spark to individual
cylinders at the right time and order, the spark is controlled
electronically though the electronic ignition system.  The coil pack is
where the actual electrical current (spark) is sent to each spark plug via
the wires.

2)  The pack is generally comprised of a metal base with a plastic
top (insulates the metallic parts so the current is not immediately
grounded).

3)  The coil pack is located on the right side of the engine (look
from the front) under the plastic manifold covers.  Just follow the pretty
spark plug wires to the end and they attach to the coil pack.

4)   It seems that the VR6 coil packs (at least pre 98's) just suck.
I am not sure if the plastic is not formulated properly, if the molding is
not performed properly or if the design does not distribute stress/heat well
but by listening to the problems people on this list have had, the coil pack
is NOT a quality part.  Either that or it is designed obsolescence, keeping
the dealer stocked with easy, $500 repairs every 30,000 miles.

Part II - Diagnosis

1)  If you have noticed that on cool, damp days or after driving in
the rain (especially on the highway, especially behind cars/trucks) the
engine is running rough and misfiring, chances are the coil pack has a
crack(s).

2)  When this happens, the "check engine light" WILL come on
immediately, because the emissions just went to hell.

3)  If possible, pull over and pop the hood ASAP.  If it is a
cracked coil pack you will notice (at least I did each time there was a
problem):

a)  a fairly loud "snapping" or "clicking" sound immediately
followed by a rough spot in the idle.

b)  visible sparks running along the coil pack, generally
from the wire terminal (where the spark plug wires attach) towards the metal
part of the coil pack.  Each spark is tracing a water filled crack and
grounding the spark to the engine block rather than travelling along the
spark plug wire.  Try to remember or draw the location of the sparks.


4)  If you cannot pull over, or if you want to check later after the
weather gets a bit nicer you can easily simulate rain.  Get a plant spray
bottle/mister and fill with clean water.  Start up the engine and give the
coil pack area a good misting with the bottle.  It may take a few sprays to
get the pack nice and wet.  This should start the light show again.  Try to
remember where the crack(s) is or make a sketch.

[ It would also help if you do this in a darkened garage
or at dusk.  It would make spotting the sparks a lot easier.
Obviously.  aqn ]

5)  You now know you have the dreaded cracked coil pack.  But have
no fear, there are options...

Part III - Repair Options

1)  Take car to dealer, tell them the coil pack is bad.  They will
respond "that's nice but we will have to confirm" ($56.49).  They will then
call back several hours later saying "you have a bad coil pack" (duh) and
that for just $350 in parts and $100 in labor we can put on a new one.  So
pony up $500.

2)  Lucky for you, there are engineers out here who just can't stand
it when a biased party tells me that an inferior part needs to be replaced
with the same inferior part.  So like all good men, especially engineers, I
start to tinker.  Leading to a "fix" that has worked for 11,000 miles so far
- The $3.49 Epoxy Solution.

Part IV - The $3.49 Epoxy Solution

1)  Drive a different car to Home Depot, Lowe's, etc. and get a
package of high strength, high temperature epoxy.  I *think* the brand I
used was "Poxy-Weld"?  It is the classic twin tube syringe, silver in color
with a cardboard packaging display that unfolded to give product
information.  It is made to repair metal, plastic, etc. with higher
operating temperatures.  It has Kevlar flakes to add
strength.  I think the one I used was rated to 250 or 350 degrees.  It was
like $3.49 for the tube.

2)  In order to make the repair you will need:
torx wrenches or driver
allen (hex) wrenches or driver
damp rag
hair dryer
epoxy
12 hours (1 hour working, 11 hours waiting)

3)  Coil pack removal.  This is very easy.  First remove the plastic
manifold covers.  This requires torx head wrenches/driver.  IMPORTANT.
Before trying to loosen the screws, bang the top of the wrench/driver with a
hammer while the wrench/driver is on the screw.  Aluminum tends to "corrode"
quickly (look at the manifold) and slightly bond to itself.  By hitting with
a hammer, the bond is broken and the screws can be easily removed.  I know
this from experience (ie partially stripped screw heads).  If you strip the
screw heads, I used a slightly larger allen wrench and literally hammered it
into the torx grooves.  Of course you then need new screws ($12).   Once the
four screws are out, plastic covers come off easily.  You can now see the
whole coil pack.

4)  Unplug the wire harness attached to the top of the coil pack and
move out of the way.  If I remember right it has pinch clips on the side to
unlock the harness.  Unplug the spark plug wires.  Make a diagram of which
plug number goes where.

5)  The coil pack is held to the engine block by four, long allen
(hex) screws.  I found a hex driver with an articulated joint made the
removal easier.  A socket wrench should also work.  Unscrew and remove the
pack.  It is a bit heavier than you might think so be careful when removing
the last two screws.

6)  Take coil pack inside.  Ignore the "you are not a mechanic"
insults coming from the living room (be the ball Danny).  Take off plastic
cover on the top of the pack (just pop over the small clips).  Wash off the
coil pack with a damp cloth.  If it is really dirty, a bit of Dawn can work
wonders.  Just make sure to wipe off the soap well.  You will now want to
dry the pack WELL with the hair dryer.  I was probably a bit anal about it
but I sat in front of the TV for like 20 minutes just drying the pack.
Since there is no real way to tell if all the water is out of the cracks, I
was conservative.

7)  You are now ready for the epoxy.  Mix a healthy amount is a
small disposable container.  I used a popsicle stick to mix and spread.
Start applying a liberal coat of epoxy.  The first time I did it, I only
covered the places I had seen sparks.  Of course about two weeks after the
first fix, a new crack or one I had not seen developed so I did it again.
This time I covered the entire plastic portion of the coil pack.
Concentrate on the area between each terminal and the edge of the pack.  No
problem since.  So either coat the cracked areas or just do the whole thing.
I would recommend the whole thing.  The epoxy tends to get a bit sticky so
it may work best doing two batchings.

8)  Set coil pack in a warm place to dry overnight.  I did this in
December so by a radiator worked well.  Just don't put outside since it
makes the curing take a lot longer.

9)  Reinstall the next morning.  I actually did this before work one
day and it took all of about 10 minutes.  Put plastic cover back on pack.
Install pack with four hex bolts and reattach the wire harness.  Plug in
spark plug wires in SAME LOCATIONS.  Install plastic manifold covers (I put
some grease on the aluminum screws before installing to prevent locking).

10)  Start car and she should be running like new.  It will take at
least 3 warm-up/cool-down cycles to reset the "check engine light"


I hope this helps those interested.  It has worked like a dream for me.  And
at 3.49 vs. 500.00 it is a no brainer to at least try it.  Worst case you
know how to install the pack and can just order the part from a mail order
place (Adirondack, potter, etc.) saving the dealer rape.

I would actually recommend doing this as preventative maintenance.  It's
cheap, easy and can same some significant bucks.  If I ever HAVE to get a
new pack I will do it before installing, just to reinforce it against
cracks.  Feel free to write back with any questions.

Marc
97' Jetta GLX - Red/Black

Just wanted to say, whoever thought of the epoxy fix for the coil pack is a
genius! Also thanks to Marc Gallagher for providing great instructions for
the fix. Side note: it is not necessary to remove the manifold cover to undo
the coil pack.

I swear, the car actually feels smoother now. Maybe it's just in my head...

Kevin Ng
97 Jetta GLX Windsor Blue

It's hella easy. Just be careful if you decide to do it right after driving
home. Lots of piping hot parts around the engine bay! Good thing I had
protection--Mechanix gloves are one of the best investments I've ever made.

Kevin Ng
97 Jetta GLX Windsor Blue

	-----Original Message-----
	From:   Chadwick, John/COR/INV [SMTP:&#106;chadwic&#64;CH2M<img src=/i/dc.gif border=0 width=35 height=15>]
	Sent:   Tuesday, April 03, 2001 1:12 PM
	To:     Ng, Kevin; 'gtivr6'; 'jettaglx'; 'VW VR6'
	Subject:        RE: [gti-vr6] another coil pack success story

	I'm going to be doing this next Friday on my day off. Can any idiot do it?
	Anything I should be careful of? Thanks.

	Chadwick

I just ran to the hardware store to pick up some epoxy.  The stuff I got
says it's only good up to 200 degrees F.  This shouldn't be heating up
that high will it?

The stuff I got was actually called something like "Plasti-Weld" or some
such, and was rated up to 300 degrees F. To tell you the truth, I don't
really know how hot the coil pack is likely to get, but I picked up the
highest temperature epoxy I could find, just to be safe. It is bolted up
to the side of the engine block, after all, so I figured the higher the
epoxy's heat tolerance, the better.

--Griff

I am finally going to epoxy the damned coil pack since my local
weather has been wet and damp and the car bucks and stutters it
drives me loco.  A final and last question, dose the epoxy resin go
on any metallic parts?  Thanks.

When I did mine I was paranoid about that at first, but once I got
started, I didn't take much caution not to.. I don't really think it
matters.. I don't think there's any real way (or any real reason) to
ever take that thing apart, so I went ahead and sealed the line
between the plastic and the metal..

I even epoxied right over the contacts that go from the plug to the
coils (under that removable piece on the top)..

--Chris

[...]

As an update, the coil pack now has 85,000 miles on it.......had to
recoat it at about 75,000 miles.......

M-

"G.A. Chaussee" &lt;&#103;c4n&#64;virginia<img src=/i/de.gif border=0 width=35 height=15>&gt; wrote:

> The stuff you want to get is called J-B Kwik Weld. It's good up to 300 F, I believe.
> You can get it at Auto Zone or Advance or Pep Boys or wherever.
>  I did my coil pack about 20K miles ago and there hasn't been any problem since.
>  
>  --Griff 


  I guess since people are recommending J.B. Weld, it will do the job.
  Personally, I am a bit leery about using JB Weld.  I used it to (try
  to) fix the leak in my EGR valve.  JB Weld seems to be too brittle and
  doesn't stick too well to the plastic EGR valve.  I cleaned the valve
  to a fare-thee-well, too, before applying JB Weld.  After a while, the
  JB Weld separates from the valve in one location, resulting in a leak
  again.  I would go with something that might be more flexible, like the
  Plasti-Dip stuff.

--
Andy Nguyen

I finally settled on 3M 2216 epoxy to repair my coil pack.
It's been working great.

Those looking for an "industrial-class" epoxy to patch
their coil-pack may be interested in this route.  I did a
quick write-up with pictures at:
  http://www.rbeverly.net/~rbeverly/gti/coilpack.html

Cheers,

rob