Christopher Zach

So continuing my long and questionable career of rescuing orphaned Porsches, I just gave in on Ebay and bought an 85 928S sight unseen, about 300 miles away....



Yaay, another Porsche... says the wife....

I'm sure it doesn't look this good. 115k miles, 2 owners, second owner hasn't owned it long, mediocre interior but it is blue...

Plan to pick it up next weekend and drive it home. I've owned an 87 944S for about 28 years, so I know the joys of redline and the agony of defeat on the 16v DOHC engines. On that car, the worst thing that can happen is the timing chain tensioner pad fails at 160k miles, the chain hits the tensioner, breaks 3 teeth off the exhaust cam, rips the tensioner from its mounts, and trashes 12 valves. Ask me how I know :-)

So replacing the tensioner pads is the first thing when I get it. Rennlist has the top pads and says they are for the 85-86 and 87 up cars, are they the right ones? Is pulling the valve covers harder than on the 944S (which is like falling off a log)? What is the next big thing that can go bad aside from the timing belt (done that too on the 944S)?

I suppose this car doesn't have the balance shaft belts so there is that.

Anything I need to watch out on the automatic transmission? CV joints known to blow up? Does the 85 paint have that annoying clear coat that totally peeled on my 87 (yuck!)?

My skill level is pretty good on fixing things myself, I did the head swap/rebuild/replace on the 944S and it's running fine 50,000 miles later. Likewise did the timing belt (87 944S's had the self adjusting hydraulic belt tensioner, does the early 928S have it as well?) and the galley plug issue (which the 85 928S doesn't seem to have). Fixing interior stuff is more annoying to me than the engine, but I will probably need to do some of that as well. Goal is a presentable semi-daily driver for 10 mile commute to work and something with a bit more pep than the 944S.

Thanks!
Chris
(Owned 74 914, 68 911L, 87 944S, now 85 928S)

The Forgotten On

Welcome to the magical realm of 928 ownership, where you will spend more money on your can than your wife

Anyway, here are a few things to answer some of your questions.

Replace the chains and pads with the IWIS racing variety. They have the best chain strength as they are as strong as the originals. The others went to thinner links.

Also, replace both the top and bottom pads. You don't want to have to go back into the engine again.

The pads for the 85- early 86 are NLA last I knew and you have to update to the later tensioners with the correct adapter hard line ( Mark A. should have some used at 928 international)

The auto itself is bulletproof.

The issue with them is that the drive shaft inside of the torque tube stretches from years of accelerating and puts pressure on the crank leading to TBF.

You can remedy this with an improved clamp or monitoring it closely and releasing the tension when necessary.

The CV joints rarely fail and when they do it is because a boot ripped and road grit wore away at the bearings. IIRC the 930 uses the same CV joint, or at least they did up to 1982.

I hope this helps and I am sure many more will add to this information to help you get started.

cpayne

Welcome! If the rest of the car looks like the side in the pic, then it looks like a pretty nice beater. More pics when you can.

Mrmerlin

I would inspect the chain pads, and usually just put new powder coated cam covers on,
and dont mess with the pads.
I have not seen many that have been worn down but worth a check.
NOTE if these were hi wear items then you would still be able to buy the ones needed for your year.

NOTE the new tensioners were a design change so maybe the pad interchangability was designed out to force new parts to be purchased.

NOTE since this is a V8 it has a lot more time running at lower revs VS the 944 engine thus less wear will occur along the timing chains .

I have a 86.5 parts car with full S4 suspension and big brakes if you need parts. 19027

hacker-pschorr

Your purchase popped up on Facebook the other day:
I thought someone posted it up here too, I cannot find the post.

Beautiful car, love the color combo. That drivers seat looks savable to me. I would reach out to Rob Budd @ Classic 9 Interiors:
http://www.classic9leathershop.com/


The pads on the 32V engines are not known for failing like the 944S/S2. I've owned an S since 1996 and suffered the pad failure destroying the camshafts (by some miracle the heads / valves survived). So I'm very familiar with this situation.

It is something 928 owners should check and at some point replace, it's not as "mission critical" compared to the 944 engine using the same system. My 87 just turned 100k miles and I have no intentions of replacing the chains / pad any time soon. Probably when I powder-coat the covers, most likely next winter.

As mentioned above, they are 930 CV joints, extremely strong. This 928 is still using stock joints and axles:
https://rennlist.com/forums/928-foru...-a-veyron.html


The drive shaft doesn't stretch, they act like a jump rope when spinning, swinging in an ark which pulls at both ends. Over time the clamps holding them in place lose tension, allowing the shaft to pull out. Once the engine slows down the shaft relaxes and is now putting pressure on the flex plate.

That's why one solution would actually be to loosen the clamps so the shaft can freely move back and forth in the splines. The downside to this is noise (they tend to rattle) and you will wear out the splines prematurely. This is why nobody actually does this.

Christopher Zach

Yep, with the 944S I'm kind of used to this. 914 class car with 911 priced parts. At least most of the 914 parts could be sourced from a VW Bus. :-)

That's a bit of a pain. I'll check with pelican parts, see if they have any of the older style. When the tensioner on my 944S exploded, the pads were ripped apart and broken, but not really worn. So I always wondered if the plastic just cracked and failed. One other thing I noticed: The pressure reducer valve that goes into the 16v head in the corner was defective; it could have been overpressure on the cam chain tensioner that broke the pads as well. So when I replaced everything I made sure to include the overpressure valve as well.

Good. My S had a click in the rear CV joints on hard turns at full power at about 50k miles, had them repacked, went away till about 150k, I've been running an experiment for the past 70k miles to see if they fail. Nope so far.

Thank you for the comments. Glad to see there is a good solid community for the 928; I used to post a lot here in the 914 days and I kind of missed that.

C

Christopher Zach

Really? I don't have facebook access, is everyone a-twitter? :-)

Thanks, I love the color blue, and the paint does look pretty good. Were these cars painted with a different type of paint (non clear-coated)? I'll check to see if he can do a toofer for my 944S as well. That bolster wear is pretty common. I haven't seen the car yet, will drive up with the dad in the 911L next week but I was a bit concerned about water damage to the interior. Guy says nope, we'll see.

Oh yeah. When it happened to me I checked the timing belt, found it intact, pulled the valve cover, stared at it and had a good cry. Then parked the car for 2 years or so, then after having my kid I would wake up at 5am, feed kid, go outside, and spend an hour doing one thing on the car each day. One day was loosen cam caps a bit, then more the next day, eventually pulling the head, repairing it, putting in new cams/valves, etc.... Took about 6 months to fix it but it worked perfectly. Glad the 928's don't seem to have the problem, interesting.

Interesting, I'll check for this when I get it home.

Thank you for the thoughts, looking forward to seeing how this thing works out. Worst case it breaks down on the roadside and we tow it with the 911L. :-)

C

SeanR

Don't bother going to Pelican Parts for anything 928. Check out 928sRus and 928 International.

hwyengr

It's not just that the lower pad is NLA, it's that it's not serviceable on the S3 (85-early 86) engines. The later tensioners can change both, but as mentioned above the swap can be tough due to rare oil pipes.

zekgb

Stan you've got mail.

bureau13

What is the official name of this particular color? I really like it...

Christopher Zach

Red.

PorKen

928s never got a proper tensioning/dampening system (too low sales numbers, IMHO) but it can be added.

davek9

Last time I tried 928 International did not have the correct Oil feed lines for the S4 chain tension replacement/retrofit. The S4 oil lines can be carefully reshaped to fit the S3 heads to the S4 tensioners.

So.. buy a used set of S4 tensioners and all the bolts and Oil feed pipes that go with them as the mounting bolts are different too. Then buy new top and bottom pads, and don't look back

I've been seeing warn pads on at least 3 '85, 86.5 and even '88 S4's (w/ 88k to 130k mi.) that I would not feel right about putting the cam covers back on w/o replacement as groves were warn into them and the plastic was shredding off.
These parts are ~30 years old, remember that

Welcome and that shark looks great

Dave K

Landseer

I had a chain derail on 85. Gave me a year of ticking noise that I ignored.