maydog Posted October 15, 2004 Report Share Posted October 15, 2004 I got a code 0300 today (engine misfire) I could tell that the engine is running pretty rough. I pulled the plugs and they all have a reddish deposit on them - the ceramic and tip are covered in red and black. I had pulled a plug this summer and the tip and ceramic were nice and white. Are the plughs bad. I had added some stop leak to the oil - could this have been the problem? The plugs have 40K on them Link to comment Share on other sites More sharing options...
Marika Posted October 15, 2004 Report Share Posted October 15, 2004 I got a code 0300 today (engine misfire) I could tell that the engine is running pretty rough. I pulled the plugs and they all have a reddish deposit on them - the ceramic and tip are covered in red and black. I had pulled a plug this summer and the tip and ceramic were nice and white. Are the plughs bad. I had added some stop leak to the oil - could this have been the problem? The plugs have 40K on them There's a fuel additive called MMT that can leave a red deposit on spark plugs. Supposedly, it's not used here in the US. Here's a PDF file I found that was a study done on the effects of MMT on cars. http://healthandcleanair.org/mmt/ford.pdf I don't know if what you added to your car has MMT in it. If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans. Link to comment Share on other sites More sharing options...
maydog Posted October 15, 2004 Author Report Share Posted October 15, 2004 It was bars's leak stop oil leak, I will have to look at the bottle Link to comment Share on other sites More sharing options...
maydog Posted October 15, 2004 Author Report Share Posted October 15, 2004 here is a blurry pic of one (please no quips about the +4s) Link to comment Share on other sites More sharing options...
bigfoo Posted October 15, 2004 Report Share Posted October 15, 2004 it's pretty normal for plugs to be reddish blackish, in fact they should be with not many deposits.. unfortunately mine are too white which means i'm running a bit lean........hopefully will fix that soon by adjusting the maf or when I have enough $ to get the new computer Link to comment Share on other sites More sharing options...
Logan Posted October 15, 2004 Report Share Posted October 15, 2004 Thats pretty red....wow. Here is a link that may help. Dry white plugs is what you hope to see. Hey Bigfoo...what is it that makes you think your PCM is bad? http://www.classictruckshop.com/clubs/earl...spark/plugs.htm Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
Ranger Posted October 15, 2004 Report Share Posted October 15, 2004 Notice the Recommendation" on the NORMAL plug "If the plug has been in service for more than 10-12,000 miles, the entire set should probably be replaced with a fresh set of the same heat range". They forgot to mention the points and condensor.I can't help but wonder when that was printed. Link to comment Share on other sites More sharing options...
maydog Posted October 15, 2004 Author Report Share Posted October 15, 2004 Well I replaced all of the plugs and cleaned up some corroded connections and the car still runs like crap. Some of the plugs I pulled out were in pretty rough shape looks like they got too hot. I was going to swap out some of the coils to see if they were a problem but I threw out my spares cleaning the garage this summer, doh! Is there any way for the home mechanic to know which cylinder misfiring? The shape of the plugs makes me wonder if something else is to blame, like the fuel mixture. I have noticed that when I open the door the speakers crackle a little - maybe there are some electrical gremlins. I'll be hitchin a ride to work tomorrow. Link to comment Share on other sites More sharing options...
JimD Posted October 15, 2004 Report Share Posted October 15, 2004 .... Is there any way for the home mechanic to know which cylinder misfiring? .... OBDII DTCs should tell you which cylinder is mis-behaving. P0301 through P0312 = cylinder 1 through cylinder 12. Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
Marika Posted October 15, 2004 Report Share Posted October 15, 2004 here is a blurry pic of one (please no quips about the +4s) When I compare this plug to the images that Logan posted, I would say the colors are almost a perfect match. Looks like MMT contamination. If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans. Link to comment Share on other sites More sharing options...
Marika Posted October 15, 2004 Report Share Posted October 15, 2004 I have noticed that when I open the door the speakers crackle a little - maybe there are some electrical gremlins. I'll be hitchin a ride to work tomorrow. Before the control module died for my blower a few weeks ago, I too noticed a popping or clicking sound coming from my speakers. Now you have me wondering why too. If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans. Link to comment Share on other sites More sharing options...
bigfoo Posted October 15, 2004 Report Share Posted October 15, 2004 Thats pretty red....wow. Here is a link that may help. Dry white plugs is what you hope to see. Hey Bigfoo...what is it that makes you think your PCM is bad? http://www.classictruckshop.com/clubs/earl...spark/plugs.htm heh, you don't want to see TOO white of a plug my PCM is fine, i'm hooking up a new engine management computer so I can tune all aspects of the engine...... I wonder how much havoc that will wreak on the Pcm though once i've disconnected the pcm from all it's toys :> Link to comment Share on other sites More sharing options...
maydog Posted October 15, 2004 Author Report Share Posted October 15, 2004 The service manual does not list codes 301-312, I think the northstar does not use them. I am probably going to rent a scan tool, if it can read the misfire counters. Link to comment Share on other sites More sharing options...
Logan Posted October 15, 2004 Report Share Posted October 15, 2004 Strange but true....most Cadillacs are limited to a specfic PO300. Thats it. Some other GM products will set a PO303 or 304 depending on which specfic one is missing. Example: My 2001 Deville is limited to just PO300. A Tech 2 will clearly show a misfire. This one happens to be ours.... http://images.andale.com/f2/115/106/376867...11783_tech2.jpg Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
bigfoo Posted October 15, 2004 Report Share Posted October 15, 2004 LOL Logan, you just LOVE posting that tech2 image.. why not just make it part of your sig? :) Link to comment Share on other sites More sharing options...
maydog Posted October 16, 2004 Author Report Share Posted October 16, 2004 I borrowed a scantool from a local checker auto - It game me a code 303 - cylinder 3 misfire. Funny - the DIC only reads 300. Cylinder 8 was fine. I swapped coils and the miss followed the coilpak - so I bought a new one. Everything is fine now, I still wonder about the old plugs, how did they get so bad? Link to comment Share on other sites More sharing options...
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