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« on: 25 May 2010, 15:37:07 »
I have just started suffering an intermittent misfire on my '02 Omega 2.6 auto. First time was a few weeks ago, at cruising speed on a trailing throttle the engine misfired for about 5 - 10 secs, after which the emissions warning light flashed a few times, then all returned to normal. Second time, again on a trailing throttle, while towing a van, similar 10 sec or so misfire, followed by flashing warning light, but this time the light stayed on. Pulled in, stopped and re-started the engine, light went out and no sign of a misfire. 150 miles later in the same journey, the misfire returned, but this time it persisted, most noticeably at low rpm (2500 or so), and accompanied by the emissions warning light. This time I kept going to my home, with a misfire all the way, for 1/2 hr or so, but once home, switching off then restarting the engine cleared the problem. Suspecting oil in the plug wells, I pulled the offside coil pack and plugs - all clear and plugs good. Despite the spaghetti covering the nearside coil pack, I got it lifted enough to check for oil and to remove the front plug - plug was clean, but all 3 plug wells appeared to have had coolant in them at some time, to judge from the residue, but were otherwise clean and were dry. The car has not lost any coolant while I have owned it (35000 miles), so I assume the residue was from an old problem. I have since done over 400 miles with no recurrence of the misfire. So - I'm stumped, but the prospect of the problem returning at an awkward moment doesn't make for relaxed driving! Have any of you experts out there got any ideas what the problem might be and where to go from here?
