Originally Posted by
TarlCabot
it will have failed guides and bent valves at the least... also, very scored cylinder walls
Nay.
Broken or slipped timing chain/belt doesn't always mean broken/damaged guides or scored cylinder walls...chances are actually good that it is not the case.
Bent valves...broken timing belt at 65-70...a certainty. You'll also most likely have a few damaged lifters due to them being sandwiched between the piston and cam lobe when the valve slammed into the piston at the same time the cam lobe came in contact with the valve...ask me how I know.
The pistons themselves are only bad if the valve manages to hit on the outer most rim or if it manages to crack it...it could also snap a connecting rod, but this can easily be determined after the heads are removed by rotating the crank and pushing down on each piston as they reach top dead center.
On my motor, on each cylinder, only two of the three intake valves were bent...the two setting side by side...all the 5th valves were fine. As for the exhaust valves one on each one. Only surface damage to the pistons.
Good luck and hopefully things aren't too bad.
At the engines mileage it'll need new valve seals too.
Originally Posted by
Dagear
Hello All.
I was bit by the VW / Audi Bug in the mid 1980's, Vehicles owned 3 Type II vans, 1980 -4000, 1987- 4000 Quattro, BMW R1220RT & R1150 Moto's
Currently looking at 2005 S4, Owner states he was cruising at 65 to 70 then engine light blipped and engine went dead. Towed Home now only runs REAL rough and only for few seconds. Due to the price, I am considering purchasing. The timing belt work doesn't bother me, more complex than my Honda Odyssey, VW Bug, Honda CRV but still a timing system.
Looking for input on how to check if the vehicle has valve or piston damage. Thinking of using inspection camera via sparkplug hole to check out piston tops. But unsure of how to test valves is there a location on this engine to manually crank over? Thinking of threading in a compression testing and manually crank over.
Thoughts?
Originally Posted by
badger.
1. Chains are not really necessary to replace IMO. I've never heard of chain breaking or being damaged (unless a guide or tensioner had catastrophically failed). Mine are at 197k now and still just fine AFAIK.
2. As far as bare minimum, neil mostly got it I think. I would disagree slightly on the sprockets; depending on your time to do the job, I would recommend making the call whether you need those or not until you can inspect your current ones. I think very long term they would need replacing due to the inherent material issue causing the pin hole to wallow out, but there have been people with 150k+ miles on them and they aren't wallowed out at all. Basically what I am trying to say is you may or may not need them, and you can save yourself a lot if you wait to inspect your existing ones (ask me how I know...) The sprockets that are included in the JHM Intermediate and higher kits and add ~$750 to the cost. Alternatively, once in a while some people have swapped in the JHM ones and have low mileage stock ones they are willing to sell. I sold mine (with 160k on them but very little wallowing) for like $40 to someone since I didn't need them anymore.
For a "one stop" shop to get the guides and whatnot the JHM Basic kit is probably a good bet ($1000) as it gets you all new guides (including the RS4 version of the one) and MOST of the little orings and seals you would need. Pick through
my old thread (just one of many on here with lots of good timing info); there is a spreadsheet I made with lots of part numbers and a few other posts with parts info if you want to try and piecemeal it cheaper.
3. The RS4 specific P/N is floating around in many threads, I think a little digging and you can find it. I don't know if offhand though. Might even be in that post I linked above haha. As far as being worth any extra cost = YES.
4. I would recommend using the tools. They are cheap insurance. You can rent them or buy them, or there are many people on here that own them you can borrow from for much cheaper than renting elsewhere.
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