2003 Lincoln Aviator 4.6L DOHC V8 AWD
For the last year or so this car has made a ticking sound on startup particularly on cold days. Its while the engine idles and would go away as engine warmed up. Lately with the cold weather here in Chicago it is even more noticeable and as engine warms it gets quieter but not completely gone away. The ticking varies with RPMs and seems to go away at higher RPMs.
I've probed around with a stethoscope and hose trying to find the source. I even took off the serpentine belt and ran it briefly to see if it was belt related. It wasn't so this would seem to rule out alternator. AC Compressor, PS pump and idler/tensioners.
I've heard about broken exhaust studs being a common problem but the sound is like metal tapping noise not the thud or rumble I would expect from an exhaust leak. My hose listening didn't pinpoint a leak but in fairness it was hard to be thorough given limited access to exhaust manifolds.
My initial thought was a sticky lifter but I've tried a couple of valve "potions" in the oil to no effect.
So I don't know if I have a bad lifter, broken exhaust manifold studs, or some problem with the timing chain and guides.
Sound familiar to any of you? Any suggestions appreciated.
:frown2:
For the last year or so this car has made a ticking sound on startup particularly on cold days. Its while the engine idles and would go away as engine warmed up. Lately with the cold weather here in Chicago it is even more noticeable and as engine warms it gets quieter but not completely gone away. The ticking varies with RPMs and seems to go away at higher RPMs.
I've probed around with a stethoscope and hose trying to find the source. I even took off the serpentine belt and ran it briefly to see if it was belt related. It wasn't so this would seem to rule out alternator. AC Compressor, PS pump and idler/tensioners.
I've heard about broken exhaust studs being a common problem but the sound is like metal tapping noise not the thud or rumble I would expect from an exhaust leak. My hose listening didn't pinpoint a leak but in fairness it was hard to be thorough given limited access to exhaust manifolds.
My initial thought was a sticky lifter but I've tried a couple of valve "potions" in the oil to no effect.
So I don't know if I have a bad lifter, broken exhaust manifold studs, or some problem with the timing chain and guides.
Sound familiar to any of you? Any suggestions appreciated.
:frown2: