audijsh2413

Ok so my 2.8l 12v v6 has started to show its quirks, I was diagnosed with a bad lifter, and audi suggests you should re-do all the lifters instead of replacing just one. ($$$$$$) Heres what I need help with, should I put a bigger cam in while all the lifters are being re-done, or will it hinder more than it will help??

hubturn

Maybe I'm showing my age, but I though overhead valve engines do not have lifters, at least in the sense of the traditional V-8 with lifters, push rods, and rocker arms. Does Audi consider the contact between the cam lobe and the disc above the valve stem and spring a "lifter?" Time for somebody to educate me. According to 12v.org the AFC and AAH engines differ in the cam and valves so be sure of what you have before doing anything rash, like spending a bunch of money.

QPower95

I just had the heads all broken down on my 2.8 about a month ago. When I did my head gaskets, I replaced the valve stem seals and had the heads decked. It's not as much of a traditional lifter like in a pushrod motor. It's really a cam-follower seeing as the cams push down on them rather than push up on them like in a pushrod motor. Lifter, cam-follwer, same thing.

The cams and cam followers are pretty easy to take out, although I would recommend getting the timing belt tools so you can make sure everything is in-sync when you put it back together. Under each valve cover are eight bolts that hold the cam girdles down. Take those off and the timing sprockets off the front and the cams come right out. The cam-followers/lifters are underneath and they slide right out. It is a good idea to replace all of them, but if you know what particular lifter it is, they're about ten bucks each. I order through Getcoolparts.com because its one of the few places you can get single parts, unlike Audi which will want you to buy a whole set. When you put the cams back in, re-torque the girdles to 15 ft/lbs.

http://www.getcoolparts.com/ShopByVe...llower&mode=PA

These lifters will work in both AFC and AAH motors I think. The parts numbers are the same on getcool for both motors.

As far as cams go, they're pretty pricey and few and far between. I thought about the same thing, but the only set I could find was a used set of Schrick Cams on Ebay and they were $800. I decided just to do a little porting rather than camming cuz i'm broke.

CRAZY_RUSSIAN

cams
http://www.eurospecsport.com/product.../camshafts.htm

audijsh2413

Thanks for the replys i really appreciate it, and i just talked to the 4th mechanic about my car, and he diagnosed low oil pressure, now i seem to trust this guy a little more on what might be wrong with it not only because he has worked at an audi specialized shop for years... but instead of going in and replacing all the lifters or cam followers in the engine it might simply be an oil pump going out.. Has anyone had the same thing happen, where the engine begins to make a ticking noise, or an occasional chatter?

QPower95

2.8 do get noisier as they get older. If the oil pressure gets low, the lifters stay dry and chatter like crazy. I'd take the valve covers off and make sure the oil passages are clear. Also, there are valve bodies or something in the valley pan. Their job is to hold oil in the top of the engine for cold starts. I've read about these going bad (they're plastic and they crack) and when they do the engine can get really loud. Also, I'd check your oil pressure switches. They break or blow through when they get old. There are two on top of the oil pan behind the oil filter that screw in and have one wire going to each of them. That's a cheap fix and could be the problem. If you blew an oil pump, you would know.

audijsh2413

awesome, thanks for the info... hopefully its one of those things, i would tear into the motor myself, but its my daily driver and im unexpierienced with audis and i dont screw anything up.. but all thats going to change, im going to tech school in september

CRAZY_RUSSIAN

i would first start with the oil pressure check valves, the ones that are underneath you intake. get intake gaskets, valley pan gasket, and a set of those valves

audijsh2413

atlast the mystery noise has been identified, you were right about the check valves under the intake, the engine had great oil pressure in the bottom of the engine, but my lifters and valvetrain were near bone dry.. now i need some ideas on where i can find such check valves for sale ..