valve tapping

Message Title: Message Text:  http  https  ftp  mail    hr     highlight   LI   Quote  Select Emotion SmileWinkSadEmbarrasmentDisgustedBig GrinMadShockedTongueCoolFrownConfused [q]The tapping stopped on its own, not likely for a valve, correct? It stopped for a few months - no noise at all. Before it stopped, I checked the engine with a stethoscope. I pinned the noise down to number 3, inside the valve cover. Recently the noise started again, but this time it was more of a clatter. It was intermittent. The engine started running rough at times, especially at idle. It would be idling smooth and then suddenly pick up a miss. Then the miss would disappear. This leads me to believe that the problem must be an injector nozzle. Now I notice that when I run it with the pedal to the floor, I get a continuous trail of heavy dark gray smoke from the exhaust, even when the clattering sound has subsided to zero. That is new. Ordinarily the smoke was only mildly apparent on continued hard pull. I think now that this must be a faulty injector nozzle. I am very cautious about bringing this truck into Caterpillar. I have heard horror stories about how seemingly minor problems can turn into million dollar repair bills. I ain't rich. A bum injector could behave intermittently, couldn't it, clattering and then quieting down, and then suddenly clattering again? A malfunctioning injector could cause a lot of smoke on hard pull, correct? Even if it's not missing at the time?[/q]

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