A guy/friend I work with has a '95 TC that has a few issues, but the most pressing one is it has, what sounds like to my ears, a lifter that isn't oiling right. As loud as it is, it may not be oiling at all. The poor 4.6 literally sounds like a diesel. The motor revs good, seemingly has all of it's power, and doesn't smoke. It's got 128k miles on it. The tick is coming from the passenger side bank of the engine and increases with the engine RPM. Is there a somewhat simple fix?
11-23-10, 06:47 PM
The 4.6 and 5.4 have a problem with breaking exhaust manifold studs which results in an exhaust leak. I'm sure if you googled "ford 4.6 exhaust manifold leak" you'd be overwhelmed with a large amount of hits. Sometimes an exhaust tick sounds JUST LIKE a valvetrain noise. Ford later switched to stainless studs from the factory, which I have yet to see break.
Also, the EGR tube attached to the left hand exhaust manifold likes to rot out and leak near the manifold.
It's definitely coming from the top of the engine and is decidedly metallic.
11-23-10, 07:13 PM
Well, that engine is OHC with roller followers, so valvetrain noise on those is very rare. If it's actually confirmed that the noise is under the valve cover, then you'll have to physically pull the cover and inspect.
Given the above, valvetrain noise would really surprise me, though it's not impossible. My money is still on the exhaust manifold. It can even confuse the most experienced mechanics who are too quick to diagnose...it's easily mistakable as a internal noise.
The only other suggestion I can give for a loud top end ticking is a noisy injector.
The first thing that went through my mind was actually an injector, but typically with a noisy injector the engine will drown it out when you rev it up. This is extremely loud. Loud enough to be heard in the car while accelerating, even gently. It really does sound like an old diesel.
I own a '95 Town Car Signature series. For the same reason many other Cadillac owners have one... something different.
I like it quite a bit. Comfortable, smooth ride (but not as smooth as my Cadillacs), pretty good acceleration and quite good fuel mileage (18-25 mpg). The engine is very smooth.
I really like the controls on the steering wheel for cruise control, climate control, radio station selection and volume. The rear air suspension was replaced before I bought the car. The only problem I've had with it is the driver's side window motor and regulator (that was a weak spot for these cars).
It had 109,000 miles when I bought it in Oct., 2006; now it has a little over 120,000.