2000 SL2 misfire

[wrparks]

I was just browsing the internet at work, and apparently the brown stain I mentioned earlier was the corona stain that is mentioned on the NGK website http://www.ngkntk.co.uk/technicaltips/coronastain.asp. Good to know I guess. Haven't done a compression check, but hope to carry it somewhere to have it done soon. I'll keep you all up to date. Just went by autozone the other day and had the codes checked and reset and it is still the p0301 cylinder 1 misfire.

[mkary]

I just returned from my local Saturn shop... They discover that my problem is a couple of things... These consist of the 2/3 coil pack giving a fluctuation of resistances. Apparently it was all over the place. Next was the ECT Sensor and connector are giving incorrect readings. Also the valve cover is leaking slightly allowing small amounts of oil into spark plug 4. I got them to price out the parts directly from them and here is what they said:
ECT Sensor-$20.40
ECT Connector-$54.68
2/3 Coil Pack-$103.62
Valve Cover Gasket-$61.81

I'm gonna call around cause i am sure i can find everything for cheaper.
I will let you know how it all goes after i fix it all up. Hope this ends up being all thats wrong!

[saturnspeed_12]

go figure, but dont cheap out on the coil or ects. you need to buy either original equipment or very good aftermarket, coil wise msd or original (gm 2 tower coil pack). now the ects the only thing you can do is buy the original. it needs to be brass tipped, not plastic. typical problem with them. parts store ects like never work.

[mkary]

I have a friend who is a parts dealer so i hope to get good prices out of her!
Thats is the only way i would "cheap out".
I defenatly want to increase preformance so i plan to get the best for what i can afford. The prices i stated are strait from the Saturn Dealership i took my car in to get checked out.

[wrparks]

Well I've come across a mystery hose connector. I made an appointment to have the compression checked monday, but thought I would go ahead and get some cleaner and clean the throttle body and check for a vacuum leak. So, I cleaned the throttle body (which by the way was extremely dirty). After that, I reassembled the air ducts, and went around the engine spraying the throttle body cleaner listening for a difference in the sound. I found a spot where the engine would rev a bit if sprayed and looked expecting to find a bad hose. Instead, I found what looks to be a connector where a hose should be, but is not. Facing the engine from the front of the car, the connector is on the side of the motor almost directly behind the spark plug for cylinder 1, but is just slightly to the right of there. It is under and to the right of the support bracket for the power steering fluid reservoir. What the devil is that connector for, because try as I might, I cannot find another connector for a hose anywhere and can't seem to find the right place in the haynes manual to find it.

[sickcallawayc12]

I wouldn't get that MSD coil pack unless you REALLY want to, not much better than stock if at all.

[saturnspeed_12]

Originally Posted by wrparks

Well I've come across a mystery hose connector. I made an appointment to have the compression checked monday, but thought I would go ahead and get some cleaner and clean the throttle body and check for a vacuum leak. So, I cleaned the throttle body (which by the way was extremely dirty). After that, I reassembled the air ducts, and went around the engine spraying the throttle body cleaner listening for a difference in the sound. I found a spot where the engine would rev a bit if sprayed and looked expecting to find a bad hose. Instead, I found what looks to be a connector where a hose should be, but is not. Facing the engine from the front of the car, the connector is on the side of the motor almost directly behind the spark plug for cylinder 1, but is just slightly to the right of there. It is under and to the right of the support bracket for the power steering fluid reservoir. What the devil is that connector for, because try as I might, I cannot find another connector for a hose anywhere and can't seem to find the right place in the haynes manual to find it.

i dont want to take any guesses on it, but are you able to take a picture of this?

[wrparks]

Unfortunately not, no digital camera right now. I went by autozone to see if they had any idea, but it was a no go. Best description I can give is that it is a metal tube pointing straight up. It looks like there is a 2 inch rubber hose that connects to the back of the engine block right beside this thing and it comes straight up from beside that hose maybe 2 inches set back from the side of the engine. It actually appearsto be connected to the engine at almost the same place as the bigger hose. Or coming from the other direction, it is just to the left of the throttle body but closer to the engine. Also, I stuck my finger over it when the engine was running and it has a pretty strong vacuum to it. Sorry I can't be more specific. If I can't figure it out, hopefully the guy at the repear shop will have an idea.

BTW, it seems like the problem with the rough idle is getting steadily worse over time. I drove it to the part store today to see if they had any idea about the mystery connector and I think it is worse. Let you know how the compression test comes. If it is poor compresion, would we expect valves instead since the plug looked clean? Either way, I suspect either one is beyond my time or talent level.

[mkary]

Well i have now replaced the coil pack and ECT sensor which the Saturn Shop told me where malfunctioning, and the problem is still there. I am planning on doing a compression test on it tonight. Gotta get the heaters going in the garage cause its so damn cold up here. Unfortunatly these malfunctions had nothing to do with my issue.

[saturnspeed_12]

Originally Posted by wrparks

Unfortunately not, no digital camera right now. I went by autozone to see if they had any idea, but it was a no go. Best description I can give is that it is a metal tube pointing straight up. It looks like there is a 2 inch rubber hose that connects to the back of the engine block right beside this thing and it comes straight up from beside that hose maybe 2 inches set back from the side of the engine. It actually appearsto be connected to the engine at almost the same place as the bigger hose. Or coming from the other direction, it is just to the left of the throttle body but closer to the engine. Also, I stuck my finger over it when the engine was running and it has a pretty strong vacuum to it. Sorry I can't be more specific. If I can't figure it out, hopefully the guy at the repear shop will have an idea.

BTW, it seems like the problem with the rough idle is getting steadily worse over time. I drove it to the part store today to see if they had any idea about the mystery connector and I think it is worse. Let you know how the compression test comes. If it is poor compresion, would we expect valves instead since the plug looked clean? Either way, I suspect either one is beyond my time or talent level.

id say there is a vacuum leak right there. something should go to that.

and mkary, where did you buy the ects? and did you get the connector for it?

[wrparks]

The compression was checked this morning. Shows 150 psi on all 4 cylinders. Lower than the spec 180 to 190, but w/ 120,000 mi I think it is normal. They couldn't figure out where the vacuum line went either so that is confusing. Could that single missing line be the cause of all problems, because I would think a vacuum leak would cause a p0300 or something similar? The repairmen mentioned that sometimes these things are plugged so they went ahead and plugged it up with some tube and a bolt. I'll get it by the dealer sometime to check it out. I told my wife to drive around today and see if it acts any different plugged up. I'll let you know.

They did mention that the mystery connector comes striaight up off of the same connection as the intake manifold if that helps any.
Thanks

[wrparks]

Got a chance to take the car by the dealership today. They were nice enough to tell me what the mystery hose went to no charge. Apparently, when these cars were sold in the colder northern climates there is an extra electric air pump mounted behind the head light and a vacuum line went from there to this connector. In the south, they just capped the line and it was done. Apparently, my cap dry rotted and broke off. I drove it about 30 miles today and my wife another 40 and capping it off has taken care of the rough idle completely. The guy at the dealership said that the bolt and hose should be fine and not to worry about buyin their cap. Hopefully, the misfire code was just an artifact of that, although it still doesn't make complete sense. Maybe the injector for cylinder one is slightly clogged and it was amplifying the effect of that leak, who knows. I'll let you know in a week or two, but think I have it taken care of. While I was there, I went ahead and picked up a PCV valve (still had the original) and the Z tube that goes from the air intake to the valve cover which was badly cracked. Any suggestions for other maintenance items I should do. I plan to change the fuel filter and transmission fluid in the next few weeks, neither of which has ever been done to my knowledge.

[saturnspeed_12]

too bad you didnt notice that vacuum port before. when i noticed you said that, i figured there was your problem or at least one of them. but its good to see compression is matching across the board, seems a bit low though. im too lazy to go back through the posts, but did you do a piston soak? it sounds like the valves are not seating due to carbon. im not sure on the newer engines, which im sure they are about the same, i think below 180psi service is needed. probably just needs a good piston soak and a strong fuel system cleaner and/or true injector cleaner (not stuff you buy in a bottle to put in your tank).

[wrparks]

Yea, it stinks that I didn't see that before, but it was hidden a bit and no vacuum lines went back there so I wasn't really looking there for an obvious leak. Oh well. I haven't done the piston soak yet, but hopefully will get to it. I've read that some people use the seafoam by sucking it up through the vacuum lines via the PCV valve. Ever heard of this? You're right, it recomends service if below 180 with normal being 190 psi. The local auto repair shop has an injector cleaning service, but I'm not sure what brands they use. Do your recommend these. I know it is one of those where they attach some pressurized chemical to the fuel line and run it through. Are any of the fuel additive treatments worthwhile really? I've also heard of seafoam in the gas tank.

[saturnspeed_12]

ok the piston soak may help, but it seems like there is carbon build up around the valves which is what is bringing the compression down. running seafoam through a vacuum line while its running helps clean the intake and pretty much the valves, it does nothing for the rings. doing both may help greatly, but understand doing the seafoam through the vacuum line will cause it to stall if you put in too much at a time. you have to go slow and you wont need a funnel, the vacuum will just suck the fluid right in. now doing the injector cleaner at the shop, where they use the chemical cleaner hooked up to the fuel line, is the best way to go. it can be pricy at some places, but worth it. now to keep them running good after that, i would use seafoam, marvel mystery oil, or lucas fuel treatment. i have used them all, and all seem to do well. i have even mixed seafoam and lucas for a potent mixture, which my dad told me worked extremely well, just dont want to overdue the mixture.

ok and before i forget, if you plan to do the piston soak, do it right before you are going to do an oil change because it will leak down to your oil and could have carbon deposits floating around. marvel mystery oil, main one guys use, seafoam, or gm tec(top engine cleaner)-another one guys use- are the main things to use for the piston soak. you can also do this while the engine is still warm, pull the plug pour the fluid in and then stick the plug back in. ive done it and ive heard of a few other guys, just dont do it while its HOT, let it cool a little bit and just in case you have a hot spot, it wont ignite the fluid. now just let that stuff set quite a while, i normally do 24 hrs since i have the time too, but id say about 12 hrs should be good but keep a check on the level so it doesnt completely drain down before hand. also, dont fill the cylinder up with a bunch, or you will have to crank it with rags over the wholes to clear out most before putting spark to it. just make sure that pistons are completely soaked maybe like 1/4" deep or a little more.