Ignition Coil Replacement Procedure (shown with 2003 Astro)

General technical discussion and troubleshooting
Post Reply

Topic author
chemist
I finally get the smurf thing
Posts: 155
Joined: Tue Mar 13, 2007 7:30 pm
Location: Pocono Mts, PA

Ignition Coil Replacement Procedure (shown with 2003 Astro)

Post by chemist »

I don't know how to tell when your ignition coil is on the way out. It may start with power decreases as mine did. But it will eventually fail. You could be procrastinator and wait like me, then end up doing it at the most inopportune time possible. My advice would be to do it when you do the spark plugs and wires. It's a $30 dollar part, and with as much of a pain as the engine cover is to remove, you might as well do it then anyway.

Start by removing the engine cover, as shown in one of my previous posts, found here: viewtopic.php?f=39&t=4813

Once you have that off, your ignition coil is located here:

Image

It looks inaccessible, but it isn't. The ignition coil is kind of tucked in there, but it can be gotten out. The ignition coil is contained in a bracket that has another component attached, and is bolted to top of the motor. There may be another bracket holding it down—we'll cover that later.

Start by removing the insulated wire, as shown (note: replacement wire should be obtained from a spark plug wire kit.)

Image

Next remove the wire harness on the other side of the ignition coil.

Image

The ignition coil bracket is held on by 2 – 10 mm bolts. To remove them you'll need a deep well 3/8” drive or 1/4” drive socket with one or two short to medium sized extensions. I could not give good pictures of these bolts. They are in a straight line going from the passenger compartment toward the front of the van. Note the location of the one closest to you by the position of the socket and extensions. If you look closely, just at the edge of the ignition coil shadow you'll see the second one appearing to be under the coil—it's not, it's just on the other side, toward the front of the van...

TIP: Use a telescoping magnet at the bottom of your socket to catch the bolts as they come out—if you don't know what I'm talking about, it's something like this one: http://shop.advanceautoparts.com/webapp ... RP2083____

Alternatively, dip your socket in all purpose grease before slipping it over the bolts. If your lucky, the bolts will stick inside when you pull the socket out.

Image

If you're incredibly unlucky—I was—there will be a bracket still holding it. If not, scroll down to the part where it comes out.

If you are so unlucky, remove the air intake assembly, as shown in one of my previous posts, found here: viewtopic.php?f=39&t=2699

Below are photos of that bracket I was telling you about (taken from inside and outside the van. There are two 10 mm bolts on it. To get at them, you'll need a 10 mm deep well socket, extensions and a universal joint—3/8” drive worked best for me. Either dip the socket in grease or use a telescoping magnet to retain those bolts—one is actually a nut and not a bolt.

Before you do this, there is a 10 mm screw—best removed from inside the van. In the top photo, I tried to point at it with a screwdriver, but didn't get a great photo of it. To remove, you will need a 10 mm racheting wrench. You will also need a telescoping magnet to catch this.

Image

Front of bracket:

Image

Okay, you're finally ready to pull out the ignition coil. There is a wiring harness attached to another part on the ignition coil bracket—remove it.
Image

Unless the bracket has bolts or screws, it's riveted. Secure the whole thing in something like a vise and drill out the rivets—once you have one end out, you can tap them out with a small screwdriver or something.

Image

You'll need to reassemble the bracket onto the new ignition coil.

Image

Image

Once done, re-install the same way it was removed.

TIP: As you've no doubt figured out, human hands don't reach many of the places you need to go to re-install bolts. You'll need to hold bolts and nuts in a socket, often connected to extensions and/or universal joints. One way to keep bolts in a socket is to dip the end of the socket in grease. Another is to try to position the nuts or bolts using a telescoping magnet. You take a chance either way. I prefer the grease method.

If anyone more experienced has other tips, or notices anything I might have missed, please reply to this post and give them.

Previous Vans: 1998 Astro, AWD, 138K mi; traded on 2003 Chevy Astro, AWD, 125K mi; traded on
2009 Chevy Silverado 1500 WT, 4x4, ext, long box
2007 Chevy Cobalt
1998 Maza MPV (180K mi and in need of PA inspection--only paid $500!)

Needed: a Gen 2 Astro project vehicle...
User avatar

Smiliesafari
ASV Supporter
ASV Supporter
Posts: 2667
Joined: Sat Dec 02, 2006 12:34 pm
Location: Orlando, FL

Re: Ignition Coil Replacement Procedure (shown with 2003 Astro)

Post by Smiliesafari »

I just did this on a friends '94 Chevy pickup. The magnet IS a "must have". I use a piece of masking tape to hold nuts and bolts in the socket. If you have a bench grinder or any type of grinder you can remove one side of the rivot and then drive it out with a punch. Nice write up "C". \:D/
1996 Safari SLX Hotair balloon transport vehicle

vanagon40
I am merely driving my van
I am merely driving my van
Posts: 17
Joined: Wed Feb 24, 2010 8:52 am

Re: Ignition Coil Replacement Procedure (shown with 2003 Astro)

Post by vanagon40 »

Thank you very much Chemist. My '98 Astro is new to me. Using your instructions I was able to remove the engine cover and replace my ignition coil. The instructions were much clearer than Haynes.

:cheers:
User avatar

LaGrasta
I sleep in my van
Posts: 724
Joined: Fri Jan 19, 2007 2:07 pm
Location: Mission Viejo, CA
Has thanked: 2 times
Been thanked: 3 times

Re: Ignition Coil Replacement Procedure (shown with 2003 Astro)

Post by LaGrasta »

Thanks for the great write-up!
I never changed mine and I have 153k. I wonder how long I can expect it to last. I guess I'll just do it as you suggest at my next tune-up (200k). I'm hoping my lift will make mine more accessable too. Is this an area we can upgrade with aftermarket performance products? Maybe a coil with a hotter spark?
1998 Astro, 246,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box
User avatar

kings-x59
ASV Supporter
ASV Supporter
Posts: 1374
Joined: Thu Sep 21, 2006 7:50 pm
Location: Cypress, Tx

Re: Ignition Coil Replacement Procedure (shown with 2003 Astro)

Post by kings-x59 »

Where is the Chemist anyway? haven't seen him around in quite a while :-k
'89 Astro, 4.3L, TBI. Minor intake and exhaust mods. Rebuilt 700R4 trans (by me). Corvette servo, 0.5" boost valve, police grade 1-2 accumulator spring (shifts fast and solid). B&M stacked plate trans cooler. Bilstein shocks. Belltech sway bars front and back. New head unit, speakers and subwoofer. Needs paint and a new headliner.

name's Steve
I can't remember all I've forgotten about that....
User avatar

LaGrasta
I sleep in my van
Posts: 724
Joined: Fri Jan 19, 2007 2:07 pm
Location: Mission Viejo, CA
Has thanked: 2 times
Been thanked: 3 times

Re: Ignition Coil Replacement Procedure (shown with 2003 Astro)

Post by LaGrasta »

LaGrasta wrote:Thanks for the great write-up!
I never changed mine and I have 153k. I wonder how long I can expect it to last. I guess I'll just do it as you suggest at my next tune-up (200k). I'm hoping my lift will make mine more accessable too. Is this an area we can upgrade with aftermarket performance products? Maybe a coil with a hotter spark?
While at Kragan yesterday I saw the Edlebrock display with a couple of coils that looked like they'd bolt right in. Maybe this is the upgrade.
1998 Astro, 246,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box
User avatar

MountainManJoe
I have my van tatooed on my cheeks
Posts: 3088
Joined: Fri Aug 08, 2008 12:55 pm
Location: The Pacific North Wet
Has thanked: 44 times
Been thanked: 24 times

Re: Ignition Coil Replacement Procedure (shown with 2003 Ast

Post by MountainManJoe »

chemist wrote:I don't know how to tell when your ignition coil is on the way out.
1994 and earlier
HEI coil.png
1995 and later
edi coil.png
Now you know :)

vanagon40
I am merely driving my van
I am merely driving my van
Posts: 17
Joined: Wed Feb 24, 2010 8:52 am

Re: Ignition Coil Replacement Procedure (shown with 2003 Ast

Post by vanagon40 »

Thanks again Chemist. Your step-by-step was again a lifesaver, this time on my 1999 Astro van. Went much quicker this time: 1) the engine was not covered in oil and grease like the 1998, and 2) I had experience. Finished the entire job in 4½ hours (including 30 minutes for the trip to AutoZone for the new coil). Unfortunately, it was an emergency repair, so I did not get a chance to replace the plugs, wires, etc. After replacing the coil, I did see a tiny bit of arcing from a couple of plug wires, but not the fireworks the original coil produced.

:cheers:

johnv
I am merely driving my van
I am merely driving my van
Posts: 3
Joined: Mon Mar 09, 2015 9:32 am

Re: Ignition Coil Replacement Procedure (shown with 2003 Ast

Post by johnv »

10 years later and still making happy fixers.... struggling though my 2002 and YES there's the damned added mounting with the other bracket for teh steel cables... why..?? but onward

johnv
I am merely driving my van
I am merely driving my van
Posts: 3
Joined: Mon Mar 09, 2015 9:32 am

Re: Ignition Coil Replacement Procedure (shown with 2003 Ast

Post by johnv »

Damn.
got almost all through finding these insanely placed inaccessible bolts. the last one, vertical, on the engine, that holds the bracket for teh accelerator cables, that has to come off, to get the other side of it to come off the forward ignition coil stud so you can get underneath it to the SECOND nut that actually holds that side of teh coil bracket down...
and if I take it off all the way, i see no way to be able to get it back in there again.

I need this to work tomorrow.
I'm putting it all back with the old coil while I can and hope it runs.

Need more time, or oney to pay a pro to wrangle this.

Or I have missed something.

VENT MODE OFF
User avatar

LaGrasta
I sleep in my van
Posts: 724
Joined: Fri Jan 19, 2007 2:07 pm
Location: Mission Viejo, CA
Has thanked: 2 times
Been thanked: 3 times

Re: Ignition Coil Replacement Procedure (shown with 2003 Ast

Post by LaGrasta »

I never did this swap, completely forgot. I now have 224000 on original. My thought is its a part that rarely fails, so they bracketed in place with little access because it should need replaced. However for us, who keep these vans running far longer than most anyone would dream, we need to swap this part. I suppose my day is coming.

After rereading this post, I'm half considering leaving the old part in place, unplugging it, plug in the new one and zip tie it in a nearby safe location.
1998 Astro, 246,000 miles

K&N air filter
TruCool trans cooler
2" Overland lift & 15" BFG Terrain, 3.73 gears
JET Performance SCU-2000 (Speed Control Unit)
Gabriel Ultra shocks, rear AirLift bags & sway bar
Draw-Tite Dual Port Hitch System, hitch-mounted bike rack (4), hitch-mounted cargo tray, Thule roof-mounted cargo box

Astrophysics
I sleep in my van
Posts: 974
Joined: Sat Jan 12, 2008 9:23 pm
Been thanked: 9 times

Re: Ignition Coil Replacement Procedure (shown with 2003 Ast

Post by Astrophysics »

Hi Everyone,

Some excellent ideas here. I especially like the idea of just leaving the old coil in its brackets.
I could fab a new mount. Although, the coil is fairly heavy and it does need a proper support.

Guess it is worth the challenge to remove the old using the good tips in the write up including masking tape to secure hex nuts in socket etc.

thanks to all,


AP

Bret Schmerker
I finally get the smurf thing
Posts: 104
Joined: Sun Jul 29, 2018 6:02 pm
Location: Byron, CA, USA
Has thanked: 1 time
Been thanked: 3 times

Re: Ignition Coil Replacement Procedure (shown with 2003 Ast

Post by Bret Schmerker »

:cheers: Sorry to bump an old thread, but thanks, @chemist, for the briefing. My 1997 Safari SLE packs a High Voltage Switch, and the spark coil's probably on the upper intake near the CSFI injection manifold assembly. Upgrading to a sextet of BOSCH® PLATIN+4's and ACCEL® 8.8's off a stock-replacement coil (I suspect Delphi® still builds 'em for current GM products) and new HVS cap and rotor looks straightforward. :)
1997 GMC M11006 (Safari SLE, 2WD, V6-4300/4L60-E/7.625" 3.73:1 open)
Acquired Jul 2018 / In service Sep 2018 - Nov 2022 / down due leaky valve(s) #5 cyl.
Post Reply