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On 2001-12-04 22:30, fixer wrote:
hmmm every mustang i've ever driven clunked when shifting. mine does it occasionally at low speeds. but i'm more interested in this damn tapping sound i'm getting when cold.
i'm not sure of what your experiencing but from my experience from mechanical/ lubrication, i'd like to suggest a couple of things about your tapping sound when cold.
1st, filter.. most people don't know this, but if say you start your engine and the engine taps but shortly goes away, this is due to the lack of oil on your top end during start up and once the oil pump produces suffient oil pressure it quites down. the reason for this, get this, most mechanics beleive lifters collapsing or oil pump is weak, but in reality, there is an antidrain back valve in your oil filter. buy changing to a different brand of filter you sometimes will resolve this. studies have shown that frams are one of the worst for this problem.
now if you engine is slightly tapping during cold start up and maintains that till it warms up, my thoughts is a different oil might be in order. here is how that works, some oils are low quality base stocks and can shear real easy. this is when an oil's base stock is squeezed out between to high pressure or shear zone thus leaving virtually no lubrication to protect your parts.one reason is once warmed up the viscosity improvers "thicken" the oil to a 20 or 30wt (which ever you have) thus damping the noise a little better. in a good quality lubricant, you also have an additive designed for this called a barrier lubricant that will keep momentary shearing down to a minimal. in some cases synth oils tend to be a little more prone to allow this to happen since synths flow easier than mineral oils. what you have to do is determin what type of oil your using and make adjustments, so if your useing a synth try a good grade mineral, and if mineral, consider higher grade or synth.
these are just some ideas on the tapping problem i am hearing you guys have. consider this also. for those of you that jackrabbit starts and stops, your shearing your oil and that causes excessive wear. case in point,
little lady from texas never hammers it, car runs forever, take same car put young guy who jackrabbits from light to light, car won't last. this is due to the shearing of the oil. i cover that on my site. look under states of lubrication to learn more on that.
as for rearends, again, barrier lubricants can make a difference in how much protection you have when you shear the oil out between the pinion and ring gear which i can assure you happens all the time thus the wear and noise.
let me also say that synth's are not the answer to all these problems. depending on your situation, sometimes a good group III blend might be in order.
hope this helps and also gives you some where else to look.
<font size=-1>[ This Message was edited by: bobistheoilguy on 2001-12-06 10:15 ]</font>