iowaan

2000 4.2, 125,000 miles. i have to remove the intake manifold to fix an air leak, and the valve covers to fix oil leaks. I also have to replace the radiator.

My question is should i replace the valve seals since i will have so much of it disassembled? I'm inclined to not do it, 40 valves is a lot of work. i do this work myself.

This car is my wife's daily driver, we put about 3000 miles a year on it. The body is in very good condition, i hope to run it about another ten years. i recently had the transmission rebuilt, replaced the exhaust, replaced all the front suspension links, and have installed H&R springs, Bilsteins, and Hotchkiss roll bars (before upgrading the roll bars, body roll made me physically sick).

jcman

Cam seals perhaps?
If not what makes you think the valves seals are bad??

4Driver4

Absent a compelling reason, you'd have to be crazy to touch the vavlve seals.

I agree with JC that you should look at cam seals, cam plugs, and cam chain adjuster leaks as part of your oil leak repair.

iowaan

i don't think they are bad, just old, 17 years and 125000 miles. i just don't want them to go out in the next ten years.

iowaan

thanks, i replaced the cam seals and chain tensioner at 110,000 miles.

jcman

If your thinking in that frame or peace of mind you should just have the heads redone at a shop and go the whole 9 yards....valve regrind, valve seat lapping, valve seals, valve guides, ect, ect.

iowaan

Thanks, i'm way too cheap for that.

i seem to remember from 80's VWs, valve seals lasting only 100,000 - 120,000 miles. The Diesels sucked oil and you had to pack rags into the intake to get them to stop.

Seriously, what is the average valve seal life on these ART engines?

jcman

Yep it seems not that long ago in 1988 when I pulled the head "one" on my 82 Audi 5000s 5 in-line and took it down to NAPA for a head redo for 180 bucks, easy and sorta cheap also I ran that car up to 280k on the counter.

To answer your question I don't know about the seal life and can't imagine it's awfully short by even 200k, I wouldn't be concerned about it if your not getting the "big" blue puff at start up or that last's during driving with a slight smoke screen seen in the rear mirror, keeping in mind also that our crankcase breather system if clogged or a goofed CCV "Crank Case Valve" can contribute a mist of oil into the intake.

MP4.2+6.0

So, just visiting again. I actually did it on an 2000 ART, one head. Boat load of work. I did it thinking that might be where my oil burning issue was I tied down to a specific cylinder. Only later when I took a piston out did I find it was actually a damaged bore/block right at base of stroke that caused oil scraper ring not to seal.

Net, don't unless you need to pull head(s) and cams for some reason already--bent valves, bad lifter, something. And, time any of that to a timing belt job if discretionary, since belt comes off anyway to pull heads or even cams. First, yet more specialized tools now and painstaking as valves have gotten smaller. Lots of time. And yes, I lapped valves and cleaned and all, and had head milled. Having pulled all the seals, I didn't see any serious wear. Nor any issues w/ valves beyond cleaning, nor valve guides, not lifters.

I have previously redone a 5000 head from an 85 (and fit the turbo sodium filled valves), and lots of mid 70's Audi 100LS heads. Tolerances are way different/smaller now, materials seem better, fuel quality (for valve fouling) way better, etc. The 70's ones were problematic, and back when more were stick, or even three speeds constantly coasting down (3000rpm by 60ish) the more the high vacuum pulldown induced wear on valve stem seals.

My suggestion is leave it be and let it go life of car unless true need to tear apart motor, which is basically not really economically sensible on an Audi this old. Frankly I should have scrapped the car back when tranny blew at 100K, so put too much more money and personal labor into it even then. Still on road w/ family, burning oil from the block issue.

4Driver4

It's a waste of money anyway.

Valve seals are very rarely an issue in these five valve heads. There is no common expiration date.