So, I've got a few niggling issues remaining with the Audi. They're the sort that are not immediately indicative of disaster, but they are annoying and frustrating in both their persistence and vague nature. I have yet to get a definite diagnosis, so I wanted to pick Oppo's brains and see what opinions here are.
1) Rattlesnake in mah boots
Sometimes, generally at low revs when I haven't revved the engine up enough before letting the clutch out, there is a brief 'rattle/grinding' sound that comes from the bell housing. Now, I don't think it's a synchro because all of the gears shift fine and the noise isn't specific to any particular gear(s). It also doesn't occur in neutral. It's only at very low revs, at minimal torque, with the clutch released and the throttle engaged. It usually last about half a second and then goes away. My initial thought was the clutch, but my father and his mechanic buddy Jeff both drove it said the clutch is fine and doesn't need to be replaced. Their diagnosis?
Old pilot bearing. Now, that sounds fairly serious to me, but they keep assuring me it's not. They say it's just noisy when you don't match the revs well enough and the engine bogs down due to the flywheel not having enough rotational inertia built up yet. According to them, it's just noisy, but not bad enough to worry about for a good while. They said it'll easily wait another year or so without any risk to the transmission, clutch, or fly wheel. They say that when it starts making the noise even at normal revs, then consider replacing it and the clutch.
What does Oppo say of this?
2) "Gimme a second, I'm...I need to catch my breath."
This one's a real doozie. It comes and it goes, but today it was particularly noticeable and I want to get it fixed before the big Mountain Run in October. It boils down to hesitation and noticeable bogging at higher revs.
Up to about 4,500rpm, the car pulls fine. I mean, it's still slow as molasses in a straight line, especially up hill, but not so slow as to be unsafe pulling out onto the highway. What do you expect with 130hp?
But right around 4,500-5,000 revs, it's like the powertrain...sucks. It's not quite a wall, but there's a definite shift. Suddenly it doesn't pull nearly as hard, but the engine still makes plenty of noise. The revs build slower, but they still build, however it's not linear. It'll sometimes hiccup and then 'grab' again, but these hiccups are fairly subtle and don't seem to go as far as the transmission. The engine just gets bogged down- like something is holding it back or it's not getting enough of something.
Now, I've had a dozen and more 'like causes' thrown at me from local shadetree mechanics. Clogged catalytic convert, bad fuel pump, bad injectors, timing belt getting worn, bad MAF, bad oil pump, etc. etc.
Now, in the past year, I've installed a new fuel filter, plugs, wires, distributor cap, air filter, cleaned the MAF sensor and throttle sensor plate, and I'm replacing the timing belt and lifters next week. The car has been doing this on and off for months and I personally am leaning towards fuel pump, but I want to get opinions from here as well before I lay down money.
What say ye, Oppo?
Keep in mind, I'm on a very tight budget. After replacing the tie rods, getting an alignment, installing new pads and rotors, and ordering lifters, the timing belt kit, springs, dampers, and tires, I'm going to be very lean, financially, for a while. But I'm trying to get as much done on the Audi while I can so that it's reliable moving forward. It's a touchy balance and it's stressing me out a good bit.