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Tune up a 00 Pontiac with the 3800 V-6, replace coils?

GM Guy

GM Guy

Manual Trans. 2WD Enthusiast
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Hey all,

Giving the sister's 00 Bonneville with the 3800 a tune up.

I want to put 3 new coils on, new plugs and new wires and be done with it for 100K plus, but I am getting a little push back.

Would I be OK keeping the coils and just replacing the plugs and wires?

Car has 270K, and the coils have numbers on them, so I am not fully convinced they are not the originals. Engine is super solid, as is the body, and the car can get 30 mpg, so IMO its worth the investment.

What say you guys, will bad coils cook plugs and wires if they go bad?

Thanks!
 
On coil pack engines I've always only replaced that one bad coil(s). Usually they are fairly pricey each. Done this on a Burb and Silverado a few times. Silverado still going to this day with over 200K miles.
 
I've been wondering the same since I have a 3800 series 2 in an Oldsmobile Intrigue. After my Duramax was totaled I've been driving the Olds everyday and have been picking away at all its small issues, I could get all 3 coils for under 100 bucks through the parts store but not sure if it's worth it since I have 0 misfires.

I did replace the fuel pressure regulator today, it fixed the intermittent rough idle as well as few other very intermitant issues it would have. Took less than 5 minutes and now the car runs very smoothly. I really like the 3800's myself.
 
@floyd400 where is the FPR? I am thinking that may be contributing to the dying upon first start, and a few other annoying issues, if its cheap might be worth changing. :)

I found the majority of the issue today, corrosion on one of the posts for the coil for cyl. 5, cleaned it up and it runs better. Plugs are pretty shot, so probably going to do plugs and wires and keep the coils as-is, might still buy 1 new one to keep on hand.
 
GM Guy said:
@floyd400 where is the FPR? I am thinking that may be contributing to the dying upon first start, and a few other annoying issues, if its cheap might be worth changing. :)

I found the majority of the issue today, corrosion on one of the posts for the coil for cyl. 5, cleaned it up and it runs better. Plugs are pretty shot, so probably going to do plugs and wires and keep the coils as-is, might still buy 1 new one to keep on hand.
Click to expand...
Sounds like classic FPR issue. It is located just up and to the left of the thermostat housing on the fuel rail, Has a vacuum line connected to it. A snap ring on top of the regulator holds it in then it pops out, put new one in with snap ring and your done. I would start the car first and pull the fuel pump fuse to depressurize the system before replacing the FPR. I didn't because I was being lazy and got a fuel geyser after pulling the regulator out.
 
Doing some research, I see there is a rebuild kit and a complete regulator.

complete regulator is almost double the kit. any advantage to doing just the rebuild kit?
 
Don't replace the coils. Do replace the FPR, especially if you smell gas in the vacuum line. I'd get a complete regulator and be done with it.
 
Strongly consider Iridium plugs. I like AC Iridiums which WERE NGK when I bought em, they were the factory plug as well, dunno about AC/NGK now, been 7 or so years.. They are a 100k mile plug. Set gaps perfectly. I know 'they say' that they come with the right gap, don't believe it.

Just carefully use feeler gauges and don't PRY the ground strap away using the center electrode. Many Gap tools have a notch or something to move the ground strap the non-destruct-O way.

Wires, I went with MSD spiral cores, that's been 150k ago. Loom each wire and GO. Trouble free.

3.8 series 2 is/was a good one. Of course Achilles heel, DexCool and questionable gasket materials killed many off way before their time. And how.
 
If the upper intake hasn't been replaced with the updated unit and EGR tube you should consider doing it. Not a hard job, I did the lower intake gasket too while I was in there, glad I did because now I have no leaks, a clean motor and peace of mind. Also I would recommend you get the aluminum coolant elbows to replace the factory plastic, leak prone ones. That should get you a pretty reliable 3800, I would drive mine across the country and back without worry, great motor. I used Prestone green coolant with no problems but the Dex Cool was already long gone when I got the car.
 
OK, got it up in front of the shop finally, and pulled the engine cover to give a bit more room to get to the back plugs, and noticed the smell of gas. Traced it to a leak at the quick connect of the high pressure fuel line to the fuel rail.

Is the seal and half of the connector serviceable separately, or am I looking at a new fuel line too? I don't have a lift, so unfortunately this one may get farmed out, or might do it on top of the car trailer where I can crawl under it easier. :)
 
I actually had a similar issue on my 89 Fox. Quick connect leaked at the fuel rail. Went to the Junkyard and pulled one off a car (the line was luckily stainless so no rust) and I haven't had an issue since.Also helped my brother install new fuel rail crossovers on a Subaru boxer engine. Was a pain, he was dealing with nasty fuel smell in the cabin when cold. Guessing the lines shrunk in the cold and leaked out the cracks. Wasn't noticeable when warm.

Scary thought on leaking gas, fire waiting to happen! Glad you found it.
 
You'll need a fuel line disconnect tool, and you can try to replace the o-rings that are in there. Otherwise to replace the ends you'll need a nylon fuel line repair kit, there's a special tool to fit the new end into the line. Not sure how it works, but I think you can rent it.
 
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