XC90 V8 Spark Plug Replacement Steps
 

I changed my own plugs today to comply with the 75K maintenance schedule and thought somebody might be interested to know that it is fairly simple. Anyone can do it but it is important to have the correct tools in a couple places which is the usual deal. My car is a 2005 XC90 V8, 74,900 mi.
I went with Volvo plugs primarily because surprisingly, they turned out to have the best price. List $78.01. My new favorite dealer even gave me a do-it-yourself break and charged $73.87! Part #30731383. I believe these are NGK Laser Iridiums with Volvo printed on the insulator.

Here's the tools I used:
1/4 ratchet, short, medium extensions, 10mm, 14mm deep sockets
3/8 ratchet, extensions, 5/8" plug socket
1/2 ratchet, 17mm, 18mm
18 mm box or combo wrench
Torque wrench, needs 22lb torque according to the manual.
small and medium flat blade screwdrivers, (for coil connectors)
New style flat gap gauge, (.044")
Anti-sieze compound
It's handy to have a small air compressor to blow/clear dust off the top of the engine so nothing falls in when the plugs are out.

One thing to remember is take it slow. the whole rear bank is done by feel with very little visual aid. Keep a finger on everything unless you enjoy removing the skid pan for bolts, seals etc.

Start by removing the cross bar /engine locator. Each end has a 17mm bolt head and 18mm nut below. The bolt thru the engine bushing is 18mm with the nut captured in a bracket to prevent turning.

Next pop off the plastic covers. They come off easy enough but then require careful twisting and turning. the rear cover seems to come easier by tilting the upper edge back to clear the engine locator mount.

The rear bank is more involved so I will go over that first. remove the two lower cover mount button/bolts (14mm). One holds the harness, the other, (between the fuel lines) just allows a little more room to move the harness. remove the two 10mm bolts that attach the harness to the head. At this point nothing really moves but when the coil connectors are disconnected it will clear the coils enough to pull them out. Unclip the rubber fuel line from the driver side clip only. this will allow clearance for the last coil to be removed,(drivers side).

The connectors are tricky. I could not release them by hand so I helped them with a small screwdriver under the lip while trying to depress the tab by hand or with a medium blade screwdriver. Once the small driver got under the connector lock tab the other driver could be used to gently slide the connector off. When all four connectors are disconnected the harness moves away enough to clear the coils.

Each coil is held down tight with a 10mm bolt. Remove it (keep a finger on the bolt) and then grasp the coil and it lifts out easily. Watch for the rubber dust seal under the head of the coil. 7 of 8 stuck to the coil and one stuck to the raised ring on the head. You don't want to go looking for that in the back of the engine bay.

Finally you are at the plugs. They are deep down in the head. A note: Very important that your plug socket is tight on the plug insulator. It needs to grip very well so there are no accidental dropping the plug in the tube. Not a crisis, but hey, why have that problem?

Remove the old plugs. If they are like mine they probably look pretty good. I double checked the gap on the new ones and they were all right on out of the package. I use a small amount of anti-sieze on the threads trying to keep it off the part that extends into the cylinder.

Now , again using feel slide the new plug down till it feel like it fits something, turn it in reverse till you feel the first thread clear then thread the plug in.

Volvo manual says torque to 22 ft/lbs but I got scared and quit around 18 ft/lbs. Believe me it was plenty tight.

Replug the coil connectors, reinstall the harness hold down bolts, reverse the cross bar procedure and move to the front bank. This will be so easy it will be time for a beer.
You only need to remove two 14mm button/bolts to clear the front harness. I found removing the oil dipstick made the cover align very quick when reinstalling.

I hope this is of interest to somebody otherwise this is a very long post. I have pictures of the whole procedure but I can't figure out the rocket science to upload them today.

Cheers,
Dana

Very good writeup!

I'm going to make it a sticky at the top of the XC90 forum.

Posting pictures is fairly easy. I use Photobucket.com as my host and then just get the web address and use the Insert Image button when doing a reply. Pictures would be great. If you can not get them posted PM me and I will give you my e-mail address and you can send them to me and I will post them.

Here is a link to the photobucket album where you can see the pictures Dana took. When I tried to post them here they came in very small and hard to see.

http://s759.photobucket.com/albums/x...3/Volvo/album/

Great post.

What manual are you using?

Great job; I will keep this in mind.
I just purchased a '07 V8 so it will be good.
Cheers,
John.

how bout one for the 2.9 l-6 i cant seem to find them ive replaced spark plugs before on a wrangler and on cars where the spark plugs are right there and easy to get at but i cant seemto find them on this car so any ideas?

Your vehicle requires you to remove all the black plastic turbo and inlet pipes on top of the motor, then you can access the black cover.

I want to say a 1/4 air ratchet with a 7mm will help you a lot, I believe about 6 hose clamps, maybe 2 t-25 screws, some black rubber hoses on bottom of inlet pipe, not too hard.

Nice write up! One question I had is $74 for spark plugs?!!? was that for all 8 or each?

V8 Sparkplugs
 

Triceratops, yes $74 bucks for the pack of eight from Volvo. Between my XC90, Vw Beetle TDI And F-250 6..0l I now have no pride nor problem asking every parts guy for any kind of a break on parts. They usually do anything they can to help. I always thought they should help in the neighborhood of 20% to their customers since competition is fierce in the after market world.
Cheers,
Dana

Cactus,
Thanks for a great write up. I just did this job over the weekend, and your how-to was the only resource I needed. Two points of input: I pulled the engine brace by removing the two bolts on each side, as well as the center bracket. That way I didn't have to access any nuts under the brace. Second point, I did the rear first, but would advise doing the front first so you can get a look at what is going on. That way you know what you are feeling for when you do the rear four. Also, you were spot on about the tight fitting spark plug socket. I had to mod mine to make it work. Also, you have to have either a 6" extension or two 3", as anything else is too short to reach or too long to clear the firewall. Thanks again, I think I saved about $150 doing this one myself.

Bludob

Great Summary
 

Excellent summary. Well written, thorough and easy to follow. Thanks you so much for posting these steps. For the first time in 20 years of vehicle ownership I was hesitant to do a plug change. It just looked too complicated on the XC90 V8. After reading your post, I decided to give it a go. After about an $80 expense on the iridium plugs, I saved over $200 compared to what the dealership was charging. The 1.5 hours was well worth my time. Thanks again, I wouldn't have attempted it without your instructions.

Thanks for the write up.
I have 98,000 on my originals.
I have the new volvo plugs in a box.
Thanks to your info, I can get it done.

VFL

Thank you very much for so clearly explaining the procedure for changing spark plugs on the XC90 V-8.

2005 vs 2008 v8 spark plug replacement
 

Are the engines similar? Is the steps to replace the spark plugs the same as the 2005? Anybody have pictures to go along with the steps?

Great blow by blow for spark plug change
 

Here is what mine looked like!
https://cimg0.ibsrv.net/gimg/volvofo...ada591006e.jpg
this is the worst of them.