How to change Ignition Coils?

[Willy]

It is always worthwhile to take a look in the How-to guides and tips
Both spark plug and ignition coil service procedures can be found there.
Willy

[levpri]

Hi everybody,
I have cylinder 5 misfire (P0305). First thing I'd like to do is replace the ignition coil. Is cylinder 5 on the left or right when facing the engine? (sorry for a silly question)
Thanks.

[Sasquatch]

Hey, some of the earlier photos are not showing up. Can those of you who posted them please refresh the links?

Oh, the reason I found this thread is the wife called, freaking out. She said the car check engine light not only went on, but was flashing! She was able to pull over to a parking lot and have her mother come get her. I thought for sure the timing belt went, but now I don't think so, as the engine is still running, though roughly. First, is this an "interference" engine (for valves when the timing belt fails)? Second, she limped it home maybe 2-3 miles, and it runs rough.

My thought is that it ran real rough as the coil was failing, and firing out of sequence, and now is just running "plain old rough", since there is likely no spark. Does this sound like a reasonable guess to you? How does one diagnose this? Will an engine scanning tool pick up this specific of a thing on a 2001? I really don't want to start dumping money into parts willy nilly; especially on this old pig.

[BillAileo]

1. It is an interference engine.
2. You can learn a lot having the codes read with an OBDII scanner.

[Sasquatch]

So, being an interference engine, and the fact she limped it home, we're safe there. Also since it is rough even in PARK, it isn't transmission related.

Right so far?

So, what are the exact symptoms of a coil failure?

[Astro14]

The fact that it runs at all means that the timing belt is intact...had it broken, she would not have driven it, she would have heard a horrible noise, followed by an engine that refused to run...followed by your call to the junkyard to come tow it away...

Running rough like it does is a classic coil failure symptom - you've got a misfire on one cylinder, the car knows it, that's why the CEL is on...could be an injector, or other cause, but the coil is most likely...

Many auto parts shops will plug in an OBD-II reader for free and pull the code, if I recall correctly, it's 030X for a misfire, with X being the cylinder at fault. An OBD-II reader is about $50 for one that just does the generic codes...

Swap coils from the bad cylinder to any other cylinder, if the code changes to that cylinder with which you did the swap, then you've found your problem.

[Norbecke]

Just my .02 I would replace all five coils. When I did mine they all failed one after another. If the coils are the problem.

[Sasquatch]

It's so easy there is no need for instructions. Here is what you need to do :

-Remove the top plastic cover and the top timing belt cover with T25 (or T30, not sure which). There should have 8 screws total.
-You will see the coils so do one at a time by unplugging the coil, remove the 10mm bolt holding the coil, pull it. Put the new one in the same position then screw the 10mm bolt back, not tightening too much (it's only 18 lb/po of torque, about hand tight).
-Put back the cover and tighten the torx screws.

It doesn't get more easier than that. the only needed tools are the right torx bit (or screwdriver like me) and a 10mm ratchet/screwdriver.

2 questions:

1) If I do the swap, can the cover remain off when testing? (I haven't looked yet, but am assuming a yes here.)

2) Should I disconnect battery first?

Thank you.

[Astro14]

in order

1. Yes

2. No

It's an easy swap...

[Sasquatch]

Well, I did this, and when testing, it ran extremely rough, and threw another code for an Audi. I think it was 1284 or something like that. I think the diagnosis was a fuel pump #2 or something. I thought about it, and reconnected the air intake tube, and it pretty much cleared up the problems. I think being a turbo, that needs to be in place, but was never mentioned here or in the directions. Anyone doing this in the future, remember to reconnect the air tube first.

Oh, and all my wiring sheathing is crumbling. The entire top of the motor when I took off the plastic coil cover was full of little bits of plastic. This is VERY worrisome. Also, I snapped off one of the plastic clips which hold the wire/plug onto the coil. I think I am just going to use some steel fishing wire to wrap it in place. This car is turning out to be a real P.O.S. in the end. Nice looking, nice riding, but it is beyond its time and was grossly underengineered.