Fun spark plug discussion

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The current thread on spark plug metallurgy and the difference in lifespan of the plug got me thinking: what is the biggest pain in the rear spark plug change you've experienced? The discussion in that thread had many comments referring to using long-life plugs to avoid having to do the job again, which is a massive selling point given the lack of access on many newer vehicles. It got me thinking, though, what other vehicles are a pain to do plugs on? Certainly they haven't all been invented recently... I've heard stories of the trouble people had changing plugs on the big-blocks that were stuffed into intermediate cars back in the late 60's - early 70's.

I wasn't around at that time, but here's a short list of what I've come across as being "difficult" spark plug changes:

Any F-series with a mod motor. 4.6 SOHC probably the easiest, 5.4 3V easily the worst
Any S-series truck/SUV with the 4.3
Any "cab over" van (a la Astro, Express/Savanna, E-series)
Any Toyota or Nissan V6 (especially the 3.5 Toyota and VQ engines in FWD, minivans are the worst)
Any DOHC Subaru (the SOHC is cake)
Trailblazers with the 5.3/6.0
The Opel-designed V6 in Saturns and early CTS'

I'm sure there's more I'm forgetting, but that tends to happen when you work on so many different vehicles. So what say the collective? Which spark plug replacement really stuck it to you?
 
The original VQ30 in the 95-99 Maxima is no problem at all because Nissan was smart enough to put cutouts in the intake to allow for easy replacement
smile.gif

Unfortunately, for the next generation starting in 2000, they stopped doing that, making the rear plugs impossible

It's impossible to change the spark plugs on a 4th gen Camaro/Firebird because they tuck the engine under the windshield.

Most FWD GM cars with any pushrod V6 require the use of a crowbar to tilt the engine forward to access the rear bank

And yeah, the minivans are the worst. That's why I suggest the 4-cylinder Sienna to people looking for a minivan
 
Back three plugs of the Ford 3.0 Vulcan are a pain but better if you pull the passenger side cowling and the air intake on the driver's side. No real need to take off the upper intake manifold but some do.

Chev 6.0 LS V-8 in pickups used the same head design on both sides, so the plugs are tilted to the front on the driver's side, (good) and to the back on the passenger side (bad). I take off the passenger side wheel and go in from underneath the fender. Others use the " Flying Superman" stance and come in from above.
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Originally Posted by slacktide_bitog
The original VQ30 in the 95-99 Maxima is no problem at all because Nissan was smart enough to put cutouts in the intake to allow for easy replacement
smile.gif

Unfortunately, for the next generation starting in 2000, they stopped doing that, making the rear plugs impossible

It's impossible to change the spark plugs on a 4th gen Camaro/Firebird because they tuck the engine under the windshield.

Most FWD GM cars with any pushrod V6 require the use of a crowbar to tilt the engine forward to access the rear bank

And yeah, the minivans are the worst. That's why I suggest the 4-cylinder Sienna to people looking for a minivan


I forgot about F-bodies. Pretty much any engine in those is a pain, from the V6 to the LS.

Definitely most minivans, although I find the later model Caravan's with the 3.8 to not be terrible. They moved the cowl back on those. The early ones were certainly tougher.
 
The Ram pickup with 5.7 hemi's are allot of fun. 16 plugs and you have to do 8 of them on a step ladder, by feel and the plug wrench is too long to get over the back plugs.
 
Originally Posted by Chris142
30 years ago I replaced the plugs and wires on a ford Aerostar van. Took me a full 8 hr day!


The Aerostar! I forgot to lump that one in with the cab-over vans, but that's a contender no doubt about it.
 
Care to be taken with the early Ford V10 with the 3 thread aluminum heads. Took me forever to replace the 12 plugs in my 2000 ML320
 
I changed all the spark plugs on my DTS when the car reached 100K miles in September. It was a pain getting to the back spark plugs and removing a bunch of stuff to access them.


However, the car ran MUCH better with the new plugs so the effort was worth it.
 
Ford Explorers with the 4.0L Cologne V6 want you to donate a little skin and blood. I've heard the F-Body Camaros are fun too...
 
Originally Posted by A_User55555
I changed all the spark plugs on my DTS when the car reached 100K miles in September. It was a pain getting to the back spark plugs and removing a bunch of stuff to access them.


However, the car ran MUCH better with the new plugs so the effort was worth it.


I feel your pain. The N* became much more difficult when it switched from coils and wires to the ignition cassettes. Does your have secondary air injection, aka California emissions? That makes the rear bank even more of a treat...
 
"Sunbeam Tigers with the Ford 260/289 were difficult, but they provided a little access door behind the glove box so you could go through the firewall and reach the back two plugs on the right side" So I'm told....
 
F series 4.6 and 5.4s aren't really a problem. Access is fine, but the two piece plugs from 2004 to late 2007had a tendency to carbon up on the extended electrode making them break on removal. This was fixed with new heads in late 2007 that have completely normal plugs. I could change them on my 2009 5.4 F150 in about 40 minutes without issue. Before 2004 the threads were a bit short and care needed to be taken not to over tighten.

Much bigger issue is our 2005 Toyota 3.3l. The intake manifold, wiper tray and a bunch of plumbing needs to be removed to get to the rear bank.
 
The Ford freestar you take off the wipers and remove the module under the window. Takes 20 minutes the second time. then all wide open.

Rod
 
Originally Posted by slacktide_bitog
The original VQ30 in the 95-99 Maxima is no problem at all because Nissan was smart enough to put cutouts in the intake to allow for easy replacement
smile.gif

Unfortunately, for the next generation starting in 2000, they stopped doing that, making the rear plugs impossible

It's impossible to change the spark plugs on a 4th gen Camaro/Firebird because they tuck the engine under the windshield.

Most FWD GM cars with any pushrod V6 require the use of a crowbar to tilt the engine forward to access the rear bank

And yeah, the minivans are the worst. That's why I suggest the 4-cylinder Sienna to people looking for a minivan


We owned a Chevy Lumina 4 door sedan w/ 3.1l V-6 FWD . With ~ 120,000 miles on the clock , it developed a miss . ( Had the codes read at O'Reilly ) . Was suggested to first replace the spark plugs .

The front 3 , close to the radiator were do-able , though not easy . The back 3 took a good part of the afternoon . Ended up taking the " dog bone " motor mount , in front , loose & using a 2' x 4" board to pry the engine to the front . This BARELY gave enough room to change out the back 3 spark plugs . ( Next to the fire wall . )

The car ran a little better but that was not the " fix " . Just used " standard " spark plugs . Figured I would never change them again .

Eventually discovered the crank shaft position sensor had a faulty / intermittent wire in the wiring harness . After I had already changed out the crank shaft position sensor . :-(
 
The old 1985 dodge 2500 van, 318. Not too bad as the dog house gave pretty awesome access.

My trailblazer was not as easy as I thought. The back two plugs had poor access due to the cowl.

My 2011 Ram 1500 with the Hemi...... the dealer quoted 3.5 hour book time. I got her done in under two... with a beer and my youngest as company. Not as bad as I was told.
 
My Traverse 3.6 was a pain, because the intake manifold had to come off first to get the coil packs off the rear 3 plugs. Then it was compounded by having the spring from one coil pack fall out into the spark plug well, and when I stuck the socket down in there I wedged the spring between the spark plug and the well. Finally had to stick a mirror back there to find out why in the world I couldn't get the socket on the plug, then looking at the coil packs and seeing that one was missing a spring. Fishing the spring out with some wire bent in a hook while looking in the mirror was an exercise.

The Midget's plugs should be easy, but #1 is obscured by the alternator. Worse, the pivot doesn't bend far enough even if I loosen it and slip the belt off; actually have to remove the alternator.
 
My first car, a used 1970 Opel Kadett purchased for its great economy of about 20 mpg! Cut my teeth (aka made mistakes) on this car without any previous experience and no adult supervision. Plugs, points, cap, and condenser were easy peasy, but I remember spending at least a half hour setting the gaps on 4 plugs. Champion plugs and Fram filters were the only brands to consider. Another half hour setting the point gap/ measuring the dwell. Then out came the timing light. Change interval was about every 12 - 15 K miles and back then cars were considered starting to be long-in- the- tooth above 75,000 miles.
 
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