Spark Plug Replacement

[V8man]

My friend came over today and we were gonna change his spark plugs. He has a 2000 Oldsmobile Intrigue, he has a 3.5 Liter V6. The spark plugs in the front of the engine were replaced easily.

The rear plugs are a different story, this is a front wheel drive vehicle, so the other 3 spark plugs are by the firewall. From my understanding, the engine will need tilting somehow, is this something that I can do?

I have a mechanic friend who works out of his garage, and he charges $50.00 an hour, so he thought the cost could be between $25.00 and $50.00

My friend got a quote from Pep Boys and they wanted $150.00 for changing the rear spark plugs.

So is this something I can tackle myself? Is all that is involved is loosening the front bolts and tilting the engine, or is there more work involved? Has anyone done this procedure in changing the rear spark plugs on a front wheel drive GM V6.

 

[147_Grain]

Replacement of the rear plugs is best done on a lift from underneath.

 

[V8man]

Originally Posted By: 147_Grain
Replacement of the rear plugs is best done on a lift from underneath.


My father has a lift at his house, is this something you have done?

 

[WishIhadatruck]

I've never done a 3.5 but I have done 3100 and 3800 GM v6's. I know on one of the 3100's you could remove the bolts on the front upper engine mounts that attach to the brace above the radiator, then there was a 2nd hole in one of the mounts that allowed you to pull the engine forward and push the bolt thru the 2nd hole holding it in place. That helped. My current 3800 is not like that. Either way, they are kind of a pain because you do them blind, but they aren't too bad. I pull one wire at a time, blow out the dirt around it with compressed air, and remove the plug. To put them back in I take a short piece of transmission cooler line and put in on the end the spark plug and use that as a handle to thread it in. It works much better than putting a straight stiff socket extension on to start it. The flexibility of the hose (just 4 inches long or so) works great to let it self align and get the threads started. I've struggled for 10 minutes on a plug before when I remembered the trick, got the hose, put it on and it started immediately. It really does work. Then put the plug wire back on and move to the next plug. One at a time to not mix up the wires.

The only issue I've ever had is if the wires have permanently attached themselves to the plug. I'm always prepared to replace the wires if necessary. If they are just standard wires (not coil on plug) then I just replace the wires automatically every 100k with the plugs. I've never owned a car with coils on the plugs, I believe they are much more expensive. I always use AC Delco parts, or Delphi I can determine it is OEM because it will be cheaper and be the same thing (for wires).

 

[MinamiKotaro]

Unbolt it and tilt the engine forward. The first time I changed plugs on a V6 is when I decided I would never, ever, EVER own anything but an inline-4.

 

[HTSS_TR]

Let the mechanic friend do the rear plugs for your friend's Intrigue. For $25-50 I would not take the risk of bigger problem if you don't know how to remove/re-install the mounting bolts to till the engine.

 

[V8man]

Originally Posted By: MinamiKotaro
Unbolt it and tilt the engine forward. The first time I changed plugs on a V6 is when I decided I would never, ever, EVER own anything but an inline-4.


How hard is this gonna be, I weigh 175 pounds, so I unbolt it, and just tilt the engine?

 

[earlyre]

Originally Posted By: WishIhadatruck
I've never owned a car with coils on the plugs, I believe they are much more expensive.


you could say that....
My old Sonata (2.4l 4cyl) was COP,coil packs on 1 & 3, with slave wires runing to 2&4. had one intermittently failing, couldn't tell which, so i just replaced both, $70 ea. for Duralast, not hyundai OE, not sure what those would have run.

 

[spk2000]

I would pay the $25-50 as they are quite a pain back there. Getting to where I no longer like trying to do those things though sometimes I try. Your friend will likely just use some jointed extensions to fish in there and get them out without too much effort.

 

[Propflux01]

The way I did it on my daughters old Grand Am, was to remove the Right front wheel, and where the tie rod comes out is an oval hole. I had more than enough room to slip my hand in there and remove the plugs. Yes, I had to use the Force (Read: Go into it blind) but it went really easy this way, took me about 30 Minutes start to finish. I 2nd 'WishIhadatruck' recommendation about using the fuel line/rubber hose to get plugs started.

 

[mechanicx]

You should be able to replace the rear plugs without rotating the engine. It's really not hard to rotate the engine after unbolting the front engine mount.

 

[71Chevyguy]

Before taking on this project make sure the motor mount on the front of the motor by the crank pulley is not leaking oil. I ran into this once and when i unbolted the top mounts to tilt forward the engine dropped on to the cradle since the lower mount was oil filled and had leaked out its oil and allowed the engine to drop. Said quite a few choice words getting that all lifted and lined up again. Since it is the 3.5 it should not be as bad since the spark plugs go through the center of the valve cover like a coil on plug four cylinder. You would not be able to get to them from underneath since the plugs can only be accesed from the top. As long as you make sure the front mount is not leaking, tilting the engine forward is simple. Just look for the extra hole in the top mount and remove the bolt for it. If you are doing it by yourself you can rock the car back and forth in park and that will cause the engine to rock back and forth with the car. You time it just right and as you rock the car forward the engine will tilt forward. You simply slide the bolt into the second hole of the mount when the engine tilts forward enough. Just watch your fingers and time it just right to slip the bolt in. It sounds a lot harder than it is.

 

[GMBoy]

I have done a 3.5 with extensions and swivels and blind feel. No need to unbolt motormounts and tilt the engine.

 

[spk2000]

Originally Posted By: 71Chevyguy
Before taking on this project make sure the motor mount on the front of the motor by the crank pulley is not leaking oil. I ran into this once and when i unbolted the top mounts to tilt forward the engine dropped on to the cradle since the lower mount was oil filled and had leaked out its oil and allowed the engine to drop. Said quite a few choice words getting that all lifted and lined up again. Since it is the 3.5 it should not be as bad since the spark plugs go through the center of the valve cover like a coil on plug four cylinder. You would not be able to get to them from underneath since the plugs can only be accesed from the top. As long as you make sure the front mount is not leaking, tilting the engine forward is simple. Just look for the extra hole in the top mount and remove the bolt for it. If you are doing it by yourself you can rock the car back and forth in park and that will cause the engine to rock back and forth with the car. You time it just right and as you rock the car forward the engine will tilt forward. You simply slide the bolt into the second hole of the mount when the engine tilts forward enough. Just watch your fingers and time it just right to slip the bolt in. It sounds a lot harder than it is.



The fluid that leaked out is a glycol based solution which is about 20% ethylene glycol or antifreeze to keep it from freezing in the winter. Doesn't really matter that much if it does but the claim is the this hydraulic bushing absorbs much more vibration and noise. I wanted to see the results of this from a previous employer where their validation results were and was never given the privilege to see the proof.

 

[V8man]

Originally Posted By: GMBoy
I have done a 3.5 with extensions and swivels and blind feel. No need to unbolt motormounts and tilt the engine.


This is what I am gonna do. I called my mechanic friend and when I go over he is gonna let me use his tools, he said he would only charge me if he does any of the work.

 

[EricF]

I'm getting ready to do my 3.5L Saturn Relay van.
I am going to remove the upper plenum, throttle body and air filter box, probably the coils and go in with a mirror and a lot of u-jointed extensions.
Felpro sells an upper set that has the plenum gaskets, TB gasket and EGR gaskets. I'm estimateing about 3hours total time, give the van sits taller and I'm not physically able to get inside tight places.
I have a tool from OTC that lets you rotate the transverse engine forward and hold it in place by mounting it in the upper engine mount, but I'm hoping by removing the plenum, I'll be to just use extensions to feed the 3 plugs.
It looks like there'll be plenty of room with it removed, and no engine rotation should be needed.
I am gonna see about removing the FR tire & maybe I can get to them through the fenderwell, but I won't know till I get into there.

 

[babyivan]

GM 3800/3.8, back plugs are not that bad to change compared to some other FWD V6 engines.
I was able to do them myself on the street.

I had a Lumina APV with the 3400/3.4 and didn't want to deal with it. My mechanic undid the mounts and tilted the engine.

I believe the 3.5 is basically the same as the old 3400.

 

[V8man]

Got the spark plugs changed for my friend yesterday, it only took my mechanic about 20 minutes, so he charged my friend $20.00

I made sure the mechanic put anti-seize compound on the spark plugs since they will probably be on there for 100,000 miles.

 

[GMBoy]

Originally Posted By: V8man
Got the spark plugs changed for my friend yesterday, it only took my mechanic about 20 minutes, so he charged my friend $20.00

I made sure the mechanic put anti-seize compound on the spark plugs since they will probably be on there for 100,000 miles.


SEE! Told you it can be done without all the engine tilting and extra work. Glad you're all good to go.