Rough Idling and Temp acting odd

[wittmc]

Sorry if this has been talked about before, just need some advice and direction on what to look at next. I have a 95 SL1 with 133,000. Good car, and so far only minor repairs. Four weeks ago it started idling rough. Idle would go way up and then drop way down, die sometimes at a stop sign or in park and overall rattled and vibrated a lot. Also noticed that the temp gauge inside the vehicle would go up to the half way mark with or without the heat on after the car warmed up. I did research and replaced the ECTS sensor and also the Throttle Position Sensor even though no engine light had come on. The old ECTS sensor was not the orginal ceramic one and was not leaking but I replaced with the OEM part from dealer but did not replace the connector. It seemed to idle a little bit better and engine temp seemed to be much lower, but this only lasted for two weeks, and now it is doing the same thing, spiratic idle and temp will start out low but when the car is warmed up and if it is in park idling the temp guage will slowly climb to half or more and then once you start driving the temp guage will go down. Also vibrates a lot when idling, It idles anywhere from 500-1000 and seems to rattle a lot more when idle is lower. Couple quick questions: Could the ECTS sensor be bad or is there a way to test it and should I have replaced the connector even though it did not look bad or dirty? Could I have overtightened it when putting the new one in? If not the ECTS, what else could cause this, EGR or the PVC Valve ? I did check last night that the fan is not coming on either with the heat or air on, so that may be the problem with the temp rising so much. If the fan does not kick on, what do I look at for this problem? I really want to figure out the idling issue and the terrible rattle and shaking when the car is in park or stopped at a stop sign. Just need some advice on where to test and look now.

[rc1488]

those idle numbers are normal. nothing wrong with them. a rough idle could be cuased by a dirty EGR. id clean that out, as a good cleaning cant hurt it

as long as the ECTS is brass and the connector did not have any visible corrosion you should be alright. however, your car has TWO sensors. did you replace the one with a 2 wire connector? its hidden underneath the EGR.

clean out your throttle body. the IAC passages may be clogged up.

take the PVC valve off and shake it. its the one part on the car that SUPPOSED to rattle

normal operating temperture for your car is around the 1/2 mark on the guage. fan doesnt come on unless its (not positive on this part) at 3/4 on the guage. heres how to make sure your fan is working
http://youtube.com/watch?v=HEIerTmMyY4
video provided by richpin

For your vibrations check your top motor mount
http://youtube.com/watch?v=oWMn1YhbXLo
video provided by richpin

spark plugs NGK Coppers and NOT platinums??????

[DonP]

Agree with rec1488.

Check your EGR.
Warm engine idle should be around 700-800 and reasonably steady.

Open road temp should reach about 3/8, maybe a bit higher on the gauge if the t-stat is working. It will go higher, to just above 3/4, with the A/C off and car not moving, before the fan comes on. If the t-stat is stuck open it will be slow to warm up, and temp gauge will stay at or below 1/4 scale on the open road.

[wittmc]

Thanks for the response everyone. I will check the EGR, the throttle body and PCV valve. The ECTS I replaced was the two wire one. The only thing is last night I was checking the wiring of the connector and about 4 inches out from the connector itself I noticed a crimp in one of the two wires, the yellow one. The crimp did not pierce the yellow casing but you could definately tell that some type of tool made the crimp, it wasn't just bent, but other than that the connector itself was clean and not corroded at all so that is why I did not replace it. Thanks also for the youtube links, I will watch those tonight. I didn't realize the fan did not come on until the temp guage got up to 3/4, that seems really high, but I also think, after you mention the thermostat, that it does take some time for things to warm up to the half mark, but that could also be due to the extreme cold we are having here in Iowa. Lot's of below zero days and nights lately. Thanks again, I will post once I check this out and let you know if the problems get resolved.

Mike

[Phredawgy]

Originally Posted by wittmc

Thanks for the response everyone. I will check the EGR, the throttle body and PCV valve. The ECTS I replaced was the two wire one. The only thing is last night I was checking the wiring of the connector and about 4 inches out from the connector itself I noticed a crimp in one of the two wires, the yellow one. The crimp did not pierce the yellow casing but you could definately tell that some type of tool made the crimp, it wasn't just bent, but other than that the connector itself was clean and not corroded at all so that is why I did not replace it. Thanks also for the youtube links, I will watch those tonight. I didn't realize the fan did not come on until the temp guage got up to 3/4, that seems really high, but I also think, after you mention the thermostat, that it does take some time for things to warm up to the half mark, but that could also be due to the extreme cold we are having here in Iowa. Lot's of below zero days and nights lately. Thanks again, I will post once I check this out and let you know if the problems get resolved.

Mike

I guess it's possible the crimp in your connector wire is causing problems or that whenever the ECTS was changed to brass the first time the connector wasn't changed and is in need of it now...

[wittmc]

Hey rc1488, in the youtube video you shared on how to check to see if your fan is working, what is it that they guys is sticking in the wholes to make the fan start up?

Thanks,
Mike

[Phredawgy]

Originally Posted by wittmc

Hey rc1488, in the youtube video you shared on how to check to see if your fan is working, what is it that they guys is sticking in the wholes to make the fan start up?

Thanks,
Mike

Looks like two pieces of electrical wiring attached to a yellow(possibly 20amp) fuse

[rc1488]

Originally Posted by wittmc

Hey rc1488, in the youtube video you shared on how to check to see if your fan is working, what is it that they guys is sticking in the wholes to make the fan start up?

Thanks,
Mike

its just two pieces of electrical wire attached to a fuse. red is 10, green is 35, so im thinking its a 20 amp. Not sure tho. Anyway its so that incase there is something wrong electrical wise, the fuse will break if the current is to high and will not hurt the fan or yourself

[wittmc]

Hey Everyone,

I just wanted to let everyone know how thankful I am for all the input to my question. I just finished taking off and cleaning the throttle body, cleaning the EGR and replacing the gasket and replaced the top motor mount by myself and all of my rough idling, shaking and so forth is cured. The motor mount was really bad and the carbon build up was unreal. It purs like a kitten and idles on the mark with no flucuation. I have never done anything like this but thanks to all of you I now have a fantastic running car and can consider myself a weekend mechanic Thanks again, hope to tackle the fuel filter tomorrow and might even consider the ball joints, but probably not

Mike

[virnin]

Originally Posted by wittmc

Hey Everyone,

I just wanted to let everyone know how thankful I am for all the input to my question. I just finished taking off and cleaning the throttle body, cleaning the EGR and replacing the gasket and replaced the top motor mount by myself and all of my rough idling, shaking and so forth is cured. The motor mount was really bad and the carbon build up was unreal. It purs like a kitten and idles on the mark with no flucuation. I have never done anything like this but thanks to all of you I now have a fantastic running car and can consider myself a weekend mechanic Thanks again, hope to tackle the fuel filter tomorrow and might even consider the ball joints, but probably not

Mike

Woo Hoo! Another happy Saturn back on the road! We all win! I'd post that A-team pic but that's somebody else's trademark!