Originally posted by duratecchie+Oct 4 2004, 12:39 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (duratecchie @ Oct 4 2004, 12:39 AM)</td></tr><tr><td id='QUOTE'><!--QuoteBegin-godspunk32@Oct 3 2004, 11:10 PM
I'm sorry to sound ignorant, but what is the problem with the V8 coil-on-plug units?
JR
The SHO coil on plug units had a nasty problem of failing, more specifically the rear bank. The rear bank plugs were between the engine and the firewall, and because it was a V8 there wasnt much room for air to get in there.
Because there was so much heat build up there and not enough airflow, the rear coils had a habit of failing. With the duratec, its a smaller engine, and theres more room for airflow up in there, so AFAIK there have been no problems with coils going bad on any gen4 tecs.
Peace out
-Damon[/b][/quote]
:withstupid:
And the kicker is that a failing coil will usually give unusual symptoms in addition to a very slight misfire at idle, a "dip" in the accelleration curve, or stalling after high-rpm use, but it is often several thousand miles later that the CEL is finally triggered and the coil completely quits. The intermittant failure of the coil is often hard to diagnose and it is sometimes hard to pinpoint which coil is the bad one. And it seems to send a pile of RF or other electrical "noise" back to the PCM, which creates problems in other areas. For example, the car may stall out and the diagnostic code may read "random cylinder misfire" even though there is only one bad coil.
It was for this reason that I replaced all four of the coils on the back bank when I got the cams welded. It cost me an extra $300 in parts, but I knew I had at least one coil that was starting to fail, and the others probably would have given me trouble later on.