2000 SL2 misfire

[wrparks]

Ok, my wife has a 2000 saturn SL2 with about 120,000 miles on it. About two weeks ago, it had a really rough idle right after cranking and at stop lights and such I thought it was going to cut off (no SES lights). We got home and I was going to take a look, but forgot and the problem was gone the next morning and I completely forgot. The other day the SES light did come on so she calls and is all worried. I send her to autozone or the like and get a code read. Don't remember the code number but it was something to the effect of "misfire on cylinder one." The plugs and wires were replaced about 6 months or 20,000 miles ago so I doubted that was the problem, but just to rule out the cheapest solution I changed the plug in cylinder 1 with the same brand as was in the other 3. No change. So, I bought an ignition coil and replaced the one that fires that cylinder. No change. What's left?

A few more symptoms. After stopping, if you let up off the brake but don't hit the gas, there is some jerkyness like it is missing, which makes sense b/c of the code. Also, the SES light comes and goes, but tends to come on after periods of idling. Once the car is moving there is no noticable misfire.
Thanks for any help

[saturnspeed_12]

ok, now what kind of wires and plugs do you have one it? although new they can be the issue. not all parts are just as good as the other, now and days you have to spend money for quality. ive dealt through many cases working in a shop. but also it could be the coolant temperature sensor (only get one from a dealer). common issue. but then too ive known of intake gaskets leaking vacuum but i think thats only on the sohc models.

it can also be the valve cover leaking oil on the plug fauling it out, but im sure you would have noticed that. now im going to stick to most likely bad wires or ects.

also you didnt happen to notice if the plug had oil on the tip? piston rings are known for seizing up due to carbon and letting oil past.

[wrparks]

I actually have the plug I took out of cylinder one with me now. As far as I can tell, the plug looks normal. In the past hour or so, I've come across quite a few posts lambasting the plugs I put in there 6 months ago (Bosch Platinum 4202). Is it true that Saturn + Bosch= problems? I just found the recipt for the wires and they are autolite professional series.

The plug itself looks good to me, everything is clean with about 1.5 turns of what is probably carbon on the bottom of the threads. Now that I look at it a bit closer, the insulator at the top of the plug where the wires attach is a bit discolored. At the very bottom just before where the nut begins, the insulator has turned a bit brown (almost the color of oil, but not slick so I'm assuming it's not oil) and it lightens up as it moves toward the tip. Is that a sign that the plug is getting too hot?

Actually, I just scraped at the brown on the plug insulator with a knife and it appears to be like a glaze that chips off. I'm guessing oil that has been baked onto it for 6 months? But how would oil come into the top of the engine there? The top the engine is clean, so it didn't run down into the plug that way and the plug didn't have wet oil on it when I pulled it out.

Either way, I would guess that unless these bosch plugs are just terrible for a saturn that the replacement I put in would have taken care of it if the plugs were the problem. But , I might change them anyway if you think that could be it just b/c they are cheap and easy. NKG?? Seems to be what people recommend. Platinum or no, I think the ones that I took out before were, but can't remember.

Thanks for the help, I'm open to suggestions as long as things don't get over my head or tools and it's probably a lot easier to get over my head than my tools. This has been a really good car for my wife and this is the first time it has ever given any trouble (well ok, it has had an exhaust leak I am putting off fixing for awhile). The original plugs and wires had been in there for 100,000 miles so I decided it was time since they reccomend a 30,000 mi interval on plugs for this car.
Thanks again.

[saturnspeed_12]

ok yes, bosch plugs are horrible and pretty much any car. euro cars seem to be fine with them but american and japanese dont like them. go with ac delco rapidfires or ngk v-power. i would also say denso u-groove but i havent tested them yet, i only will give out the good products that ive tested. now your car is probably burning oil, so if no oil is in the plug well, then id say that brown color might be coming from inside the cylinder. id say go buy the new plugs. and those wires have been pretty good, so i dont think they will be an issue.

i will also suggest an upper engine soak, piston soak. there are many different products to try. ive used marvel mystery oil and didnt see much of anything. im going to try seafoam tonight, gm and saturn both have their own upper engine cleaners too. but in order to does this, you pour the fluid down on top of the piston. fill it to where it completely covers the piston, if you have quite a bit in there, then before you start you will need to turn it over (with rags in plug holes) to shoot most of it out. you should let it soak for 24 hours, but id say 12 hours so pretty much over night. also some guys like to do it when the engine is pretty hot. they will pull the plug pour it in and hurry and put the plug back in so it really works in. i havent tried that method yet.

[wrparks]

Ok, sounds good. I'll change out the plugs asap. May be a few days, I have to work all weekend and it's raining anyway. I'll let you know how it goes. May even get a chance one afternoon to try the soak.
Thanks again.

[sickcallawayc12]

ngk is best since they fire at the right temp for saturns.

[wrparks]

I'll try those. Before I go buy, would you recommend platinum plugs for this car? I hear contradicting reports.
Thanks again.

[saturnspeed_12]

your going to find lots of people saying no on platinums. ive tested platinums and normal coppers, its all about what kind you get. ive had no issues with platinums, been very well. ive even dared to buy the splitfire triple platinums, and had everything go very good with them but the gap did spread over time.

THERE ISNT ISSUES WITH PLATINUMS IN SATURNS! there ive said it. ive tested them. i havent tested gold, nickel, or iridium. i wont test the gold ones, and nickel isnt appealing to me, so ive got iridium to do. i also have a set of denso u-grooves to test out.

[sierrap615]

i'm too tried to get into the platium thing now...

if you in fact have a SL1 with the SOHC motor a cylinder 1 missfire is a common problem caused by a leaking intake manifold gasket. the DOHC motor did not share this problem

[wrparks]

No, it's the sl2 with DOHC. Thanks thought. I still haven't done anything else to the darn car. Being lazy I guess.

[sickcallawayc12]

Originally Posted by saturnspeed_12

THERE ISNT ISSUES WITH PLATINUMS IN SATURNS! there ive said it. ive tested them. i havent tested gold, nickel, or iridium. i wont test the gold ones, and nickel isnt appealing to me, so ive got iridium to do. i also have a set of denso u-grooves to test out.

yes there is. they won't work eventually. yes some people haven't reported problems. Yet. 90% of stories that i hear about putting platinum plugs in a saturn turn out bad whether it's codes you haven't heard before, misfire, or bad gas mileage. your manual says not to use them. the experts from Chilton's and Haynes say not to use them. This is a quick tech explanation by barnowl from www.saturnfans.com. on why.
http://www.saturnfans.com/forums/showthread.php?t=70203

[saturnspeed_12]

well i think that is crap. thats saying that like dis ignitions cant use platinums. wasted spark isnt a fact for platinums not working in saturns. its just people buy junk plugs, thats all.

3000gts have wasted spark, and from factory use platinum plugs. wasted spark is not why, junk plugs.

[wrparks]

Hopefully somebody will still be looking at this post, because I am just now getting back to do a follow up. Finally bought some plugs, stayed away from platinum b/c it appears there is no use and may be bad (can you say can of worms?) Got the delco rapid fires. Put them in. No help. SES light still comes on, mostly after idleing several minutes (drive throughs and long lights). Once up to cruising speed for a few minutes, light goes of. Still jerky if you let off the brake and don't hit the gas. Feels like a misfire, but not sure. Definitely no problems with the plugs fouling. All four looked clean when I took them out. As I've said, the wires are still about 6 months old.

Now, I didn't have the computer reset after I put the plugs in, but I assume that this is moot because the light keeps coming back on. Is that right? Haven't been back to have the code read after the new plugs, but probably still the same misfire cylinder one code. I'm starting to lean towards sensor malfunctions. Thoughts?
Thanks.

[saturnspeed_12]

have you done a compression check on the cylinder then?

[mkary]

I just purchased a 1995 SC2. upon driving it home i found that it has pretty much the same troubles, when i step on the gas it seems to stumble as well as when stopping at a light if i dont keep the RPM above 2000 it will just stumble and stall. I plan on taking it in to get it diagnosed ASAP. I will let you know what they say! I'm gonna check the compression in the next couple days. I also put in new plugs and wires earlier today.