stumble when cold under moderate throttle
#1
Three Wheelin'
Thread Starter
stumble when cold under moderate throttle
Driving home tonight in the cold rain and the car stumbled a few times at about 3000 rpm about 1 kilometre into it.
It felt like a miss but the car did not throw a CEL.
I pussyfooted a few kilometres and after that the stumble was gone.
Drove home the rest of the way (about 37 kilometres) under both moderate and hard throttle without issue.
2002 996 with 232,500 kilometre on the clock, but a factory reman 3.6 litre was installed in 2005 at 70,000 kilometres.
Translation is that the engine has done 100,000 miles.
I replaced the spark plugs about 5 years and 50,000 miles ago but I've never replaced the coil packs...you see where I'm going with this.
Does the symptom as described sound like coil packs to anyone out there...?
On a related note......would the car have thrown a code without also lighting up the CEL ? I have access to a scanner ...
Thanks
It felt like a miss but the car did not throw a CEL.
I pussyfooted a few kilometres and after that the stumble was gone.
Drove home the rest of the way (about 37 kilometres) under both moderate and hard throttle without issue.
2002 996 with 232,500 kilometre on the clock, but a factory reman 3.6 litre was installed in 2005 at 70,000 kilometres.
Translation is that the engine has done 100,000 miles.
I replaced the spark plugs about 5 years and 50,000 miles ago but I've never replaced the coil packs...you see where I'm going with this.
Does the symptom as described sound like coil packs to anyone out there...?
On a related note......would the car have thrown a code without also lighting up the CEL ? I have access to a scanner ...
Thanks
#5
Race Director
Assuming the CEL is not "burned out" no CEL no code. There may be a pending code however.
100K miles and driven in sloppy weather my advice would be the same as others have offered: coils. Coils and plugs. At 50K miles the plugs don't have much service life left and you might as well start the new coils out with new plugs and be sure the correct plugs are used. Now is not the time to begin experimenting with spark plugs.
If you are feeling in a preventative maintenance mood replacing the O2 sensors may be a good idea. Or you can wait until one throws a code and then replace all 4.
100K miles and driven in sloppy weather my advice would be the same as others have offered: coils. Coils and plugs. At 50K miles the plugs don't have much service life left and you might as well start the new coils out with new plugs and be sure the correct plugs are used. Now is not the time to begin experimenting with spark plugs.
If you are feeling in a preventative maintenance mood replacing the O2 sensors may be a good idea. Or you can wait until one throws a code and then replace all 4.
#6
Three Wheelin'
Thread Starter
Thank you for that Macster. Pretty much what I was thinking....plugs and coils. The stumble did not present this morning so maybe the problem isn't serious enough yet to throw codes.
I have set of plugs and coil packs in my shopping basket at Pelican already, but I hadn't thought about oxygen sensors.... You say there are 4? I only see connectors for 2.
Will do some digging....
I have set of plugs and coil packs in my shopping basket at Pelican already, but I hadn't thought about oxygen sensors.... You say there are 4? I only see connectors for 2.
Will do some digging....
Assuming the CEL is not "burned out" no CEL no code. There may be a pending code however.
100K miles and driven in sloppy weather my advice would be the same as others have offered: coils. Coils and plugs. At 50K miles the plugs don't have much service life left and you might as well start the new coils out with new plugs and be sure the correct plugs are used. Now is not the time to begin experimenting with spark plugs.
If you are feeling in a preventative maintenance mood replacing the O2 sensors may be a good idea. Or you can wait until one throws a code and then replace all 4.
100K miles and driven in sloppy weather my advice would be the same as others have offered: coils. Coils and plugs. At 50K miles the plugs don't have much service life left and you might as well start the new coils out with new plugs and be sure the correct plugs are used. Now is not the time to begin experimenting with spark plugs.
If you are feeling in a preventative maintenance mood replacing the O2 sensors may be a good idea. Or you can wait until one throws a code and then replace all 4.
#7
Advanced
spark plugs
On my newly purchased 99 C2 I was getting similar issues when it was anywhere from 25F to -20F , it would stumble and be rough in idle for say 1km and then drive normally. When I would leave work from the heated parkade it would never stumble . If I continued to push the engine in that 1km it would throw a flashing CEL which was a cylinder 4 misfire.
I replaced the plugs and the cold weather stumble hasn't returned in the last 2 weeks. Cylinder 4 did have a leaking spark plug tube which I also changed.
I replaced the plugs and the cold weather stumble hasn't returned in the last 2 weeks. Cylinder 4 did have a leaking spark plug tube which I also changed.
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#8
Three Wheelin'
Thread Starter
I scanned the car, no codes. Has been running like a top as well.
Nevertheless... I consider this a shot across the bow. Plugs and packs are on the way.
Thanks guys. I will report back if anything more develops.
* it's definitely not bad gas......
Nevertheless... I consider this a shot across the bow. Plugs and packs are on the way.
Thanks guys. I will report back if anything more develops.
* it's definitely not bad gas......