Hi All -
Thanks in advance for any insight to my dilemma... I know enough about engines to get in trouble, the car is still under an extended warranty but I dont have Oil Change receipts... (learned a hard lesson there).
About the car...
Engine: 4.6 DOHC Mustang Cobra engine... 48k, oil changed every 4-5k. Driven like a Mustang should be... fast and straight! No high speed cornering though... or you are in the dirt! No Track time... ever! Never redlined.
Ok so here is the problem...
Upon COLD startup, I get an audible loud tick out of the engine. It goes away immediatly once the oil gets primed. This sound will not come back until 3k rpm, then it is constant... drop the R's and it goes away except on the floating throttle (that sweet spot between On the gas, and Off the gas)
It happened after a stop for smokes at the store... went in and it was fine, once I restarted it, I noticed it as I drove away.
Once the engine is warm, it does not happen except above the RMP range, and while in the throttle float. Hypothetically speaking, i could drive around all day, and never hear it until going above 3k, or the float.
I initially thought about a bent valve, but that thought went away immediatly when I heard it start one cold morning and heard the immediate loud tick! Then I thought about valve lash... which naturally led me to the lifters. I have also considered broken valve springs, but thought that they too, would make the noise all the time.
My questions to you all...
Does it sound like I am heading in the right path with the lifters? If so... I am equipped and ready to tear this thing down. How would I go about testing a lifter without tearing down the entire cam assembly? How hard will replacing the lifter(s) be if it is the problem? I know they are in a bore... can they be pulled up through the bore? How do tappets figure into the equation? Could they be the problem?
Thanks again for all your help..
Mark Hansen,
Charlotte NC
Thanks in advance for any insight to my dilemma... I know enough about engines to get in trouble, the car is still under an extended warranty but I dont have Oil Change receipts... (learned a hard lesson there).
About the car...
Engine: 4.6 DOHC Mustang Cobra engine... 48k, oil changed every 4-5k. Driven like a Mustang should be... fast and straight! No high speed cornering though... or you are in the dirt! No Track time... ever! Never redlined.
Ok so here is the problem...
Upon COLD startup, I get an audible loud tick out of the engine. It goes away immediatly once the oil gets primed. This sound will not come back until 3k rpm, then it is constant... drop the R's and it goes away except on the floating throttle (that sweet spot between On the gas, and Off the gas)
It happened after a stop for smokes at the store... went in and it was fine, once I restarted it, I noticed it as I drove away.
Once the engine is warm, it does not happen except above the RMP range, and while in the throttle float. Hypothetically speaking, i could drive around all day, and never hear it until going above 3k, or the float.
I initially thought about a bent valve, but that thought went away immediatly when I heard it start one cold morning and heard the immediate loud tick! Then I thought about valve lash... which naturally led me to the lifters. I have also considered broken valve springs, but thought that they too, would make the noise all the time.
My questions to you all...
Does it sound like I am heading in the right path with the lifters? If so... I am equipped and ready to tear this thing down. How would I go about testing a lifter without tearing down the entire cam assembly? How hard will replacing the lifter(s) be if it is the problem? I know they are in a bore... can they be pulled up through the bore? How do tappets figure into the equation? Could they be the problem?
Thanks again for all your help..
Mark Hansen,
Charlotte NC