fouled plug
07-12-2015, 03:18 PM
#1
fouled plug So I had a code pop up today, P0301(cylinder 1 misfire). I replaced the plugs at about 85k with Autolite iridium xp5245's. I have 109k now. Pulled the plug and found this . I know its a DOD plug, not really oil fouled but looks like crap. When I ordered these plugs online a few years ago they screwed up and gave me 12 plugs, looks like I am going to need the extra 4 after all if all the DOD plugs are going to throw misfire codes. I replaced the plug, as well as the MAF(Amazon 35.00). Seems to be fine now. I guess my question is this normal? Car uses no oil, and my factory plugs looked fine at 85k. Are these plugs junk? Anyone else using them? Any input is appreciated. Thanks
07-12-2015, 03:53 PM
#3
my concern would be more as to why the tip is gone on that plug, the fouling is what i would expect from an aged DoD cylinder that probably has blowby. The cylinder deactivates, blow by builds up in the cylinder, and then it burns it when it reactivates.
07-12-2015, 04:16 PM
#4
Well the tip isn't gone, just full of crap. It wasnt wet either. Here is the plug cleaned up. I just have concerns as to why this happened. Mobil 1 every 5k since day 1 and its never down anything really between changes. I will pull the other 3 next weekend and have a look at them.
07-12-2015, 08:28 PM
#7
TECH Fanatic
i noticed the same thing when i changed my plugs at 50k miles. In the mean time i would not drive around with DOD if you can help it. The gas mileage you gain is mininal , In my opinion anyways.
If you don't have the means of having the DOD Disabled, drive around in 3rd, it will keep it from activating.
I took did this practice for a long time where i only used 4th on the highway and my plugs never looked like that agian.
Now i have HP tuners and i disabled it at the beginning of this year.
I drove 2,000 miles from Tx to Kentucy and back.
and with 3.29 gears and no DOD i still got 25mpg , 2,000RPM @ 60.
If you don't have the means of having the DOD Disabled, drive around in 3rd, it will keep it from activating.
I took did this practice for a long time where i only used 4th on the highway and my plugs never looked like that agian.
Now i have HP tuners and i disabled it at the beginning of this year.
I drove 2,000 miles from Tx to Kentucy and back.
and with 3.29 gears and no DOD i still got 25mpg , 2,000RPM @ 60.
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07-12-2015, 08:34 PM
#8
i noticed the same thing when i changed my plugs at 50k miles. In the mean time i would not drive around with DOD if you can help it. The gas mileage you gain is mininal , In my opinion anyways.
If you don't have the means of having the DOD Disabled, drive around in 3rd, it will keep it from activating.
I took did this practice for a long time where i only used 4th on the highway and my plugs never looked like that agian.
Now i have HP tuners and i disabled it at the beginning of this year.
I drove 2,000 miles from Tx to Kentucy and back.
and with 3.29 gears and no DOD i still got 25mpg , 2,000RPM @ 60.
If you don't have the means of having the DOD Disabled, drive around in 3rd, it will keep it from activating.
I took did this practice for a long time where i only used 4th on the highway and my plugs never looked like that agian.
Now i have HP tuners and i disabled it at the beginning of this year.
I drove 2,000 miles from Tx to Kentucy and back.
and with 3.29 gears and no DOD i still got 25mpg , 2,000RPM @ 60.
07-12-2015, 08:38 PM
#9
TECH Fanatic
Eventually what happens is the oil gunks up in those cylinders and causes the valve guides to get fucked up, and then oil poors into those cylinders while they are deactivated, and then you get the classic Poof of smoke out the back when they light back up.
It will happen eventually. DOD is a nice thought, but its terribily dirty for the engine.
It will happen eventually. DOD is a nice thought, but its terribily dirty for the engine.
07-12-2015, 11:38 PM
#12
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I disabled the dod on my car last fall. Its way too late. Im at 156k and she uses a good bit of oil. I changed my plugs this spring (cyl 7 misfire) and the dod plugs were still really crusty even after not running dod for thousands of miles. I would turn of dod asap. May save problems down the road
07-13-2015, 10:24 AM
#16
I will look into it, but as I have said the car really isn't down any between oil changes. If its down any its less than 1/2 a quart for 5 thousand miles. Plugs being gapped wrong is on me for sure, that isn't helping I'm sure although the car has always run great and has great fuel economy. Its puzzling.
07-13-2015, 11:55 AM
#17
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07-18-2015, 08:33 AM
#19
Pulled all the plugs today, its much quicker work with the rocking the motor forward trick(thanks spawne32). As I thought would be the case, the DOD plugs were dirty, not wet just tip had build up on 3 of 4 total. The 4 non DOD plugs looked great. I replaced the DOD plugs(1,4,6 and 7), and just cleaned and re-gapped the rest. Plugs were gapped wrong at 55, don't know what the **** I was thinking before(maybe a flashback to my MSD 6A days) or possibly they came out of the box and I didn't check them. Car ran good before so nothing better change for the worse. I will monitor this better from now on. I used crap gas for quite awhile(87) when it was becoming too expensive, my guess is that in combination with the miles and wear did it. We shall see.