For about the last 1000 miles my car has had a rough idle, but only sometimes. You can also hear constant a misfire when the car is started for the first time in the morning and is at high idle during warm up. When the car is warmed up and idling I can watch the RPM sometimes drop from around 800 to below 500 and then back up. It does that pretty consistently when I switch from drive to park also. The idle also seems low most of the time when I'm sitting at a light. I was almost thinking I had a vacuum leak, but everything looks good under the hood except for a couple of oily connections on the hot pipes (new ones on order). The car drives just fine with no indication of a misfire even under heavy throttle. I also don't have any codes. I pulled a couple of the plugs today from the front of the engine to check them and the porcelain around the electrode was dark brown and wet and smelled like gas. The electrode didn't really have any build up on it, but the rest of the plug had soot build up on it. The plugs only have about 8000 miles on them as do the coils. I also just replaced all 4 O2 sensors. The plugs I bought are the Motorcraft ones that Livernois sells. I'm kinda wondering if I might need to change to a different heat range plug? Or maybe the injectors might need to be changed? The car starts fine even in negative temps and doesn't smoke at all. The spark plug wells were also clean. The O2 sensors I bought are Bosch brand. Any ideas on what the culprit could be would be much appreciated.
Rough Idle and Wet Spark Plugs.
- Thread starter 5ohSHO
- Start date
Might be time to change the pcv valve/separator. I would have said leaking VC gasket possibly, but usually that results in more noticeable driveability symptoms.
The RPM issue might be a throttle body motor fault, in addition to vacuum leaks. Were all the plugs wet with gas? Very unlikely all the injectors have issues at one time. How do the LPFP and HPFP pressures look during this time?
The RPM issue might be a throttle body motor fault, in addition to vacuum leaks. Were all the plugs wet with gas? Very unlikely all the injectors have issues at one time. How do the LPFP and HPFP pressures look during this time?
Pcv valve is in the firewall side valve cover towards the pass strut tower. Z has some pics floating around, the latest in ColoradoSHObro's thread I think.
You can monitor fuel pressures and much more using an obd adapter like the obdlink mx and software like Torque Pro. If you have an SCT tuner, even better data resolution.
You can monitor fuel pressures and much more using an obd adapter like the obdlink mx and software like Torque Pro. If you have an SCT tuner, even better data resolution.
Thanks for the pic! I didn't realize that's what that was. I was thinking of the cigarette lighter looking ones, but I think my Challenger had a similar setup now that I think of it. I was planning on getting a couple of Interceptor gauges soon, but I'll look into Torque Pro and obdlink mx.
The part numbers from the valve cover update to fix the PCV/oil consumption problem
http://www.ecoboostperformanceforum.com/index.php/topic,3836.msg79067.html#msg79067
The original metal valve cover is replaced by a composite valve cover if the TSB has been applied.
http://www.ecoboostperformanceforum.com/index.php/topic,3836.msg79067.html#msg79067
The original metal valve cover is replaced by a composite valve cover if the TSB has been applied.
Probably not an injector problem if it's affecting multiple cylinders. Kind of hard to believe you'd get multiple leaky ones at the same time, but i guess anything is possible. If you had a leaky injector, your o2's would be cutting fuel. Are your fuel trims in normal range? I'd assume they are without a code.
And the porcelain part of the spark plug was wet with brown stuff and not the electrode? You sure it was gas and not oil?
And the porcelain part of the spark plug was wet with brown stuff and not the electrode? You sure it was gas and not oil?
Figured I'd update you guys with the fix. I did change the Oil Separator and PCV valve, along with new plugs and the problem persisted. Several days after that I noticed that the car was smoking, but only when going down hill with the cruise on. The car down shifted to maintain the set speed and that's when I noticed the smoke and it was a lot. Once on flat ground again it cleared up. It seemed like a very odd thing to happen so I tried it again and the same thing happened. My friend even followed behind and saw it and said it smelled rich. I went ahead and changed all 6 injectors with new Motorcraft ones. The old ones looked terrible. The car now runs and idles great. Unfortunately while I had the intake off I checked out my valves and they are covered in buildup. Anyone know a good way to remove that stuff without major surgery? I was gonna do a write up on it also, but I saw someone else already has a good one on here, but I do have more pics of the job if anyone wants to see something.
