I have had many American and Foreign cars and I almost always de-grease and wash down the engines when I am about to diagnose a leak or work on the engine... On my 95' XJ6 with 206k+ miles? HUGE MISTAKE!!! The gasket on the top of the valve cover under the Jaguar plastic cover that seals off the "Ignition Coils" was broken and my Igntition Coils were firing in a bathtub...The car ran like molasses uphill on a cold winter day.. I pulled all the coils and dissasembled and cleaned them thoroughly ($200+ per coil) and also dried up all the water around the spark plugs and now it runs much better.. EXCEPT that it skips a beat every once in a while.. While idleing at a stop light or anywhere for that matter it purrs like a kitten, then it hiccups once or twice and were back to purring again. It does it about every 30 seconds to a minute and when it hiccups as I give it gas to drive off it needs considerably more gas to get it up and running but once were off, everything checks out fine.. My question is, what else could the water have gotten into that could cause this random hiccup?