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valve tap


sarge19446

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When I first start up my 2002 Deville, I sometimes hear what I think is a valve tapping like it isn't getting enough oil. Then when the engine heats up the sound goes away mostly. This usually occurs when the engine is cold and it is cold outside. The mechanic at the Cadillac dealer said it was due to lead deposits in the fuel system. (How can that be when I use Regular or Regular + gas at the normal gas stations? He then added an additive of some kind and the problem seemed to have disappeared. Now, summertime, I think I hear a little sound again like a valve tap. Any ideas? Does anyone else have this or a similar problem

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Tell your dealer that leaded gas hasn't been available for use in passenger vehicles for almost 15 years... :blink:

The problem could be carbon buildup - the easiest way to get rid of that is to floor it from a stop and accelerate to 80 MPH - if you see a bunch of soot/crud in the rear view mirror, repeat until the soot/crud is no longer present, the carbon is gone.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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You sure it isn't just the injectors? The injectors make a hell of a noise on newer cars.. sounds just like valve tap on older non fuel injected cars but it's just the solenoids clicking in the injectors.. Give it a few WOTs :)

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Sounds exactly like "cold carbon rap" aka piston slap. Carbon builds up in the "squish area" in the head where there is little clearance. The piston hits it and rocks on the wrist pin causing the skirt to "slap" the cylinder wall. Sounds just like noisy lifters. Harmless but anoying. I had it just the other day. Like the fellas above said, take it out an woop it. All it needs is a WOT acceleration and hold it til it shifts. The key is WOT shifts. Can be accomplished before you hit 55 mph.

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When I first start up my 2002 Deville, I sometimes hear what I think is a valve tapping like it isn't getting enough oil. Then when the engine heats up the sound goes away mostly. This usually occurs when the engine is cold and it is cold outside. The mechanic at the Cadillac dealer said it was due to lead deposits in the fuel system. (How can that be when I use Regular or Regular + gas at the normal gas stations? He then added an additive of some kind and the problem seemed to have disappeared. Now, summertime, I think I hear a little sound again like a valve tap. Any ideas? Does anyone else have this or a similar problem

What's the mileage on the car and what weight of oil are you using?

Sometimes, if the oil is too heavy (thick), it takes a while, at least until the engine warms up, for the oil to begin to circulate fully and freely so during this period, you will hear some tapping. As my mechanic explains it, as long as you don't pound on the engine while it's cold, the tapping won't hurt the engine.

If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans.

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