How to: changing spark plug + coil overs

[dsunday]

Hi all,

I’ve scoured both the internet and this forum for a how-to on changing spark plugs and coil overs for a 2009 Hyundai Genesis 4.6.

Is there anyone who either might be able to point me in the right direction or give an overview of how to do it specific to our car?

Thanks,
Daniel

 

[Audio]

I assume by coil-overs you mean the ignition coils that are on the plugs?

if so, they're actually quite simple on the genesis, with some maybe tight to get to in the rear of the engine. I'm not at my car right now, but if memory serves me correctly:
-unclip the wiring connector from the coil
-remove the 1 bolt holding it to the cam cover(I believe 10mm)
-with a little twist and pull, coil should come right off

For the plugs, I believe they take a 5/8" spark plug socket. A long extension with a wobble or u-joint will help since the cylinder heads are at a rather extreme angle towards the strut towers.

 

[QuantumRift]

I am looking for the procedure to replace the plugs in my 2012 3.8L Sedan. I know the top part of the intake plenum needs to come off but I only see to be able to find 6 hex-head holddown bolts that are very recessed down into the upper plenum. Are those the only bolts that need to be removed so I can raise it enough to change out the plugs?

 

[QuantumRift]

Never mind, I figured it out...pretty easy to do.

 

[QuantumRift]

After I lifted the upper plenum out of the way, I Just removed the col-over bolt and each plug pack came right off, no pulling or twisting, didn't even have to remove the wire connectors. SO easy a caveman can do it.

I assume by coil-overs you mean the ignition coils that are on the plugs?

if so, they're actually quite simple on the genesis, with some maybe tight to get to in the rear of the engine. I'm not at my car right now, but if memory serves me correctly:
-unclip the wiring connector from the coil
-remove the 1 bolt holding it to the cam cover(I believe 10mm)
-with a little twist and pull, coil should come right off

For the plugs, I believe they take a 5/8" spark plug socket. A long extension with a wobble or u-joint will help since the cylinder heads are at a rather extreme angle towards the strut towers.

 

[Audio]

I am looking for the procedure to replace the plugs in my 2012 3.8L Sedan. I know the top part of the intake plenum needs to come off but I only see to be able to find 6 hex-head holddown bolts that are very recessed down into the upper plenum. Are those the only bolts that need to be removed so I can raise it enough to change out the plugs?

Glad you figured it out, man. I can only speak to the coils/plugs themselves if you're doing the work on a 3.8L, I've never actually been under the hood of one. The intake on the 4.6L is quite different. But yeah, glad you got it and it certainly is easy once you start looking at it and thinking logically. More people need to curb the fear of doing the basics on their own cars. Then again, if more people realized how cheap the tools can be, and how easy some of the work can be, I'd make less money fixing their cars lol.

 

[QuantumRift]

Yea, initially I looked at this and said, "WTF?" But I have been doing my own wrenching since oh, 1973, so this is how I approached it.

Assumptions:

1) Plugs SHOULD be a fairly straightforward procedure.
2) It should not take ANY "special" tools (Hyundai only, that is).
3) It is a moneymaker for the dealer (because they will 'recommend' this procedure to an owner at some time or another, as they did for me as 'routine' maintenance).

Once I assumed that (and I don't always like to assume things), I started looking at it and identified the hold-down bolts and nuts. It wasn't too hard, then, to identify the other items that needed to be loosened and moved to get the plenum out of the way.

Could a novice or beginner do this? Probably - however, I did put in that caveat about the possibility of LOSING the two REAR 10mm bolts down the back of the engine. These 10mm bolts also have a hex 'hole' in the head as well. I initially thought the only way to remove them was with ratchet and hex ("Allen" wrench). Anyways, the two rear bolts DO affix the rear of the plenum, but NOT into the manifold..there are a couple of ears, or 'tabs' that are sleeved and threaded that stick up off the back of the manifold. So the holes these bolts go down into isn't as much of a 'captive' space (by captive I mean that if you drop the bolt down in the hole, the bolt will either fall into it's treaded socket there or just sit in there, where you can retrieve it) as it is just an "open space" under the plenum. If you attempt to retrieve the bolts after loosening them, without a magnet or a glob of grease in your 10mm socket), the bolt can easily drop off that little 'platform' and disappear into Hades, never to be seen again. THe first one I removed, I dropped, and luckily, LUCKILY it landed in a place where I could use my picker to get it (with a flashlight and mirror). Didn't repeat that problem again. Anyways, yea, it would be a 2-3 hr job for a novice - if the proper procedures are observed, and care is taken not to lose a bolt or two, and the proper torque specs are used.

Q

Glad you figured it out, man. I can only speak to the coils/plugs themselves if you're doing the work on a 3.8L, I've never actually been under the hood of one. The intake on the 4.6L is quite different. But yeah, glad you got it and it certainly is easy once you start looking at it and thinking logically. More people need to curb the fear of doing the basics on their own cars. Then again, if more people realized how cheap the tools can be, and how easy some of the work can be, I'd make less money fixing their cars lol.

 

[AJ2AWAY]

Yea, initially I looked at this and said, "WTF?" But I have been doing my own wrenching since oh, 1973, so this is how I approached it.

Assumptions:

1) Plugs SHOULD be a fairly straightforward procedure.
2) It should not take ANY "special" tools (Hyundai only, that is).
3) It is a moneymaker for the dealer (because they will 'recommend' this procedure to an owner at some time or another, as they did for me as 'routine' maintenance).

Once I assumed that (and I don't always like to assume things), I started looking at it and identified the hold-down bolts and nuts. It wasn't too hard, then, to identify the other items that needed to be loosened and moved to get the plenum out of the way.

Could a novice or beginner do this? Probably - however, I did put in that caveat about the possibility of LOSING the two REAR 10mm bolts down the back of the engine. These 10mm bolts also have a hex 'hole' in the head as well. I initially thought the only way to remove them was with ratchet and hex ("Allen" wrench). Anyways, the two rear bolts DO affix the rear of the plenum, but NOT into the manifold..there are a couple of ears, or 'tabs' that are sleeved and threaded that stick up off the back of the manifold. So the holes these bolts go down into isn't as much of a 'captive' space (by captive I mean that if you drop the bolt down in the hole, the bolt will either fall into it's treaded socket there or just sit in there, where you can retrieve it) as it is just an "open space" under the plenum. If you attempt to retrieve the bolts after loosening them, without a magnet or a glob of grease in your 10mm socket), the bolt can easily drop off that little 'platform' and disappear into Hades, never to be seen again. THe first one I removed, I dropped, and luckily, LUCKILY it landed in a place where I could use my picker to get it (with a flashlight and mirror). Didn't repeat that problem again. Anyways, yea, it would be a 2-3 hr job for a novice - if the proper procedures are observed, and care is taken not to lose a bolt or two, and the proper torque specs are used.

Q

Thanks to all the advice and experiences outlined on forum, especially from QuantumRift, I just did the spark plug replacement on my 2013 3.8L Sedan - 103k miles. I removed the air intake, unsecured the wiring harness on the driver's side (uncovering the rearmost coil), removed (on the surge tank (or plenum)) the four10mm bolts from the middle, and two 10mm nuts at the front, and loosened but didn't remove the two bolts at the back (excellent advice). Was able to raise the tank enough to clear the threaded rods at the front and move the tank over to my right, just enough to access the two covered coils on my left side. In addition to the free advice from y'all, I paid $40 for a weeks' access to www.hyundaitechinfo.com. Put in my VIN and got access to step by step procedures for surge tank removal (more than I needed but still helpful), plus torque specs for plugs (I used 14 lb-ft), coil bolts (8 lb-ft) and surge tank nuts/bolts (8 lb-ft). I used NGK DILKR7A11 Laser Iridium plugs, 0.044 gap, from Rock Auto - $15.00 each plus $6 shipping. I was relieved to see that the plugs I removed/replaced were the exact same brand, type and gap that I bought. Took 2 hours, plus test drive. All's good. Thanks again!

 

[QuantumRift]

Thx, glad u got 'er done.

Thanks to all the advice and experiences outlined on forum, especially from QuantumRift, I just did the spark plug replacement on my 2013 3.8L Sedan - 103k miles. I removed the air intake, unsecured the wiring harness on the driver's side (uncovering the rearmost coil), removed (on the surge tank (or plenum)) the four10mm bolts from the middle, and two 10mm nuts at the front, and loosened but didn't remove the two bolts at the back (excellent advice). Was able to raise the tank enough to clear the threaded rods at the front and move the tank over to my right, just enough to access the two covered coils on my left side. In addition to the free advice from y'all, I paid $40 for a weeks' access to www.hyundaitechinfo.com. Put in my VIN and got access to step by step procedures for surge tank removal (more than I needed but still helpful), plus torque specs for plugs (I used 14 lb-ft), coil bolts (8 lb-ft) and surge tank nuts/bolts (8 lb-ft). I used NGK DILKR7A11 Laser Iridium plugs, 0.044 gap, from Rock Auto - $15.00 each plus $6 shipping. I was relieved to see that the plugs I removed/replaced were the exact same brand, type and gap that I bought. Took 2 hours, plus test drive. All's good. Thanks again!

 

[skonne]

Gentleman, thank you or this info. This is the only place I could find this info (2013 Genesis, 3.8L sedan) - to save me $500+ the dealer wants to replace spark plugs. So, my question is: You make it sound as if the bolts holding down the air plenum (aka surge tank) have a hex head with an allen type hole in the middle. My plenum bolts appear to only have the allen type with a rounded outside head. I assume I will need to purchase a long allen socket wrench to get down in the plenum hole, correct? Anyone know the size (maybe 5mm)?

Again, thank you...!

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[QuantumRift]

Look closer...flashlight...I found the long allen at, of all places, Walmart in a Stanley long hex kit with handle. But as I mentioned, had I realized I could use a regular socket (12 point or 6 point) and extension. I ordered two extra bolts (one to replace the one I lost and a 'spare') from the dealer for about $12. Yea. Hyundai Part Number H 29214 3C000 bolt. They are hex heads but are not 'hexed' in middle of the bolt head. It's possible that between the '12 and '13 model years they went with a non-hexed bolt. I don't see any advantage to having a hex hole in the bolt head...but hey, I didn't design the thing. But if you don't try to remove the bolts from their holes when you raise the plenum/surge tank (hexed or not) you won't take the chance of dropping or losing one or more.

 

[skonne]

Thanks QR, I'll heed your warning on NOT removing the bolts as to not loose them in never never land...

On a side note, I see you've changed out to LED bulbs, cool idea. I've taken out my trunk bulbs though as more than once I've accidentally popped the truck with the remote and killed the battery (ughhhh...). No timed-out function on those bulbs...

 

[QuantumRift]

Incorporate a tilt switch on the deck lid.

https://www.parts-express.com/mercury-tilt-switch--060-852

Thanks QR, I'll heed your warning on NOT removing the bolts as to not loose them in never never land...

On a side note, I see you've changed out to LED bulbs, cool idea. I've taken out my trunk bulbs though as more than once I've accidentally popped the truck with the remote and killed the battery (ughhhh...). No timed-out function on those bulbs...

 

[skonne]

Nice idea...!

Cheers

 

[QuantumRift]

Well, I think a better idea is a timer...install a timer on the deck lid light circuit.

I found this on Amazon:

Small Miniature time on off cycling delay relay 0.1 sec to 9999 hours. 5V 12V 18V DC 5A. Power On Off delay, Cycling. Industrial control and hobby - - Amazon.com

it could easily be incorporated into the power wire that feeds the interior trunk lights. I...and for $17, no more dead batteries.

Nice idea...!

Cheers