January 18, 201115 yr Weird problem. Came back to my car today after being away for 2 weeks. It's very snowy and rainy outside. Almost immediately I noticed I had little power and the CEL was flashing. Engine died once or twice but came back up. Read the codes and it has misfire on all 4 cylinders. I drove around a bit, parked, cleared the codes and then it drove just fine. No codes, no low power. This happened about a month ago when it was raining, but was only cylinders 1 and 3. I got new plugs (NGK Laser Platinum) but won't change them until the weather cooperates. Right now it's the middle of winter. Lots of rain and snow knee deep. Any ideas of what else I should do? The plugs are less than a year old, but they were in my old engine when it fatally overheated. The plugs and coil are also from the old engine.
January 18, 201115 yr are you running oem plug wires? Subarus don't like the aftermarket wires, they are VERY picky when it comes to that. also, depending on your year, it could be a cracked knock sensor that is getting moisture in it....
January 18, 201115 yr If it's moisture related, I'd figure on the plug wires. You can spray them with water while it's running to see if you can create a miss. That's what I would go for first.
January 18, 201115 yr Author are you running oem plug wires?Subarus don't like the aftermarket wires, they are VERY picky when it comes to that. also, depending on your year, it could be a cracked knock sensor that is getting moisture in it.... I am using NGK Laser Platinum plugs (same as OE plugs), NGK wires (same as OE) and a coil I got at the parts store (tho I have an OE coil that I can put on). I did replace the knock sensor over the summer as I was getting a code for it. It was nice and tight when I got it in. You think there might be some moisture getting into the electrical connector? Like I said, once I cleared the codes after the engine was on for a few minutes the problem didn't come back and power was restored.
January 18, 201115 yr Author NGK wires aren't OE? Wow. I thought they totally were. Does anyone have a part number for the most recent OE wires?
January 18, 201115 yr mine did this a time or two when it was very humid, foggy, rainy, etc. to help find the cause, use a water spray mister and spray all around the engine at night while the car is running. if you have bad wires or a bad coil you should see 'arcing' or blue lights sparking. it's kind of cool. i don't know what you would see if it is your knock sensor.
January 20, 201115 yr Author Update: Went to Advance Auto Parts today and got WD-40 and dielectric grease. Took the boots off, sprayed them out with WD-40, let them dry and then filled them with the dielectric grease. Also took off the wires from the coil pack and sprayed them down. It didn't help. I am still misfiring, but it's not turning on the CEL. I am going to get new wires tomorrow from the local dealer (I have a 15% off coupon) and will also put on an OE coil pack that I have in my basement. If that doesn't solve it then I'll have to replace the plugs, but that may have to wait until a really sun and relatively warm day.
January 20, 201115 yr Spray some wd/40 on all the plug boots, and the coil boots. Only a temprary fix. If the wire insulation or boots have broken down, it wont help.
January 20, 201115 yr Author Only a temprary fix. If the wire insulation or boots have broken down, it wont help. It didn't help. See my update post, immediately above yours.
January 20, 201115 yr It didn't help. See my update post, immediately above yours. We passed like ships in the night.. Is there any oil on your sparkplug boots? And replace only one part at a time.
January 20, 201115 yr Author We passed like ships in the night.. Is there any oil on your sparkplug boots? And replace only one part at a time. No oil on the boots. I replaced the valve cover gaskets a while ago and it's holding well.
January 20, 201115 yr The spark plug bucket gaskets should be replaced with OR parts when the valve cover gaskets are replaced, just an FYI. Have you done the water spray test? Check or temporarily run a ground from near the coil pack to the battery as sometimes a bad ground may do this.
January 20, 201115 yr Author I am headed to the dealer now to get OE wires. They have them $64 and I printed up a 15% off coupon from their website. I have an OE coil in the basement that I will put on before heading out, just in case that solves the issue and I can save the coin. If neither the new coil or wires fix the problem then I'll replace the plugs, but that's a PITA as we all know. I can do it in about an hour if all goes perfectly.
January 20, 201115 yr Author Update: I replaced the coil with an OE one I had sitting in the basement (got it from a junkyard a few months ago). Started her up and all was beautiful. No more stumbling, no more low lower, no more misfire. Just for good measure I drove to the Subaru dealership 5 miles away, still with no misfire or stumbling. I figured I may as well buy the wires and I had a 15% off discount coupon, which got me the wires for $57, including tax. Replaced the wires and filled the boot tubes with dielectric grease in the parking lot and she now drives like a dream. Thanks everyone for your help. I was hoping not to have to replace the plugs and with your help I didn't have to. It also seems that I preformed a tune up! Shalom! Edited January 20, 201115 yr by bstone
January 20, 201115 yr That was pretty handy having a spare coil on hand already. Thanks for the update and glad to hear you solved the trouble.
January 20, 201115 yr If for any reason it starts happening again check the intake gasket for some reason about a year ago my wifes for escape was doing the same thing checked all the same things you mentioned and nothing we brought it into a ford dealer who did a diagnostic on it and the intake gasket was bad and when it was wet it would pull small amounts of water or snow in and give very poor performance and even kill the vehicle after having the intake gaskets replaced it runs just fine
January 20, 201115 yr Author If for any reason it starts happening again check the intake gasket for some reason about a year ago my wifes for escape was doing the same thing checked all the same things you mentioned and nothing we brought it into a ford dealer who did a diagnostic on it and the intake gasket was bad and when it was wet it would pull small amounts of water or snow in and give very poor performance and even kill the vehicle after having the intake gaskets replaced it runs just fine Good point. Fortunately for me I replaced the intake, head, cam, crank and oil gaskets over the summer. Tho I have been tempted to rent an engine smoker and check to see how they are holding.
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