NZ_928

Hi,

I'm 23 and have had my eyes on a 32v 928 for a few years now.

I'm down in New Zealand so there are not a lot of 928s around and probably less people to work on them.

What are some of the expenses of 928 ownership?

I know the timing belt is a weak spot of the car. Is the motor salvagable if the belt fails?

Would a belt fail between the 4 year/ 60 000km changes?

You don't need to talk to me about fuel consumption as I am currently driving a 1990 Range Rover Vogue 3.9L V8 auto.

I was also toying with the idea of a pre 1991 Jaguar XJ-S V12 but the rubbish build quality, poor corrosion proofing and 3 speed auto put me off.


Cheers,

pcar928fan

Doubtful you would want to bother rebuilding a belt failed motor in a 32V car. Probably cheaper (though maybe not all the way down under) to just get a decent used 32V motor to replace one. Yes, belts can fail between changes. The problem is if other things are worn and are not changed at the time a belt replacement. Tensioner, cam gears, idlers, all of these things if they are a bit worn at the time of a belt change but are overlooked could contribute to premature belt failure. That said, it is RARE to see a properly maintained 928 break a belt. The early (NON-EURO) 16V cars if they break a belt it is no big deal.

A/C systems tend to be problematic, as do power steering hoses... The three speed auto's are so-so, the early 4spds are quite a bit better though.

Most will tell you if you are not driving it in traffic a lot or if it is an occasional car then the 5spds are probably more fun and involving...should feel faster too!

Hilton

G'day and welcome

The expenses depend a lot on your own standards.. Many of us here want a 928 that drives like it left the factory, at least mechanically. That usually means it needs a bunch of work to reseal the engine (cam cover gaskets, vacuum system, intake gaskets and seals etc.), replacement of sensors which affect performance, and fixing any ugly fluid leaks. It also usually means it needs new shocks. Plus the usual wear items like brakes/pads etc.

If you're doing your own work on the car, then for the "normal" market 928 S4, you can get away with maybe $US3-4k worth of parts to make it run well - to cover timing belt, intake/vacuum system re-seal, knock sensors, rebuilt MAF sensor, new shocks, and full fluids/filters.

The minimum maintenance on a new-to-me S4 I'd go with is a proper timing belt job - where you go over the whole belt system including checking cam timing, and making sure none of the rollers and belt gears are badly worn, plus replacing all the wear items associated with the belt system.

Belts can fail at any time - however the 928 belt system is generally pretty reliable. However, the risk of belt failure depends a lot on what was done in the last timing belt job. e.g. failure to replace badly worn cam gears may lead to the belt being damaged by sharp edges on the tooth drive of the gears. Failure to replace the water pump may lead to a seized water pump bearing and very rapid belt failure. Failure to set correct belt tension may result in damage to parts of the belt train and subsequent damage to the belt.

The cost of repairing a 928 interference engine (32V, 84-86 16V) is high if the belt fails - even if only a couple of valves need replacing, you're still in for head gaskets, bolts/studs and more.

Depending on where you are, or where the cars you're considering are, a PPI by an experienced 928 mechanic is a must. I can personally Motorscience in Auckland - the owner Peter used to work on 928 S4's for Porsche in the UK and knows the cars well. Knowing before you buy the car what the likely initial expenses are will help you a lot. If you're looking to buy an S4 Auto, then make sure the PPI includes checking the crank end float - as thrust bearing failure due to pre-load on the flex-plate is becoming increasingly common - do NOT buy an Auto S4 without measuring the end-play of the crank.

Find someone local and get taken for a drive in a nice one - the yahoo "nz928" group has a good number of people on it. Not much list traffic, but a helpful bunch of people when someone does post a question.

You'll generally find it much cheaper to buy parts from the USA from the sponsors of this forum, as they deal in higher volumes and can afford lower prices. Having said which I have bought used bits from Paul at Autobahn.co.nz as he's keenly priced on some items.

Anyway, welcome to the tank - just make sure you don't get too carried away and buy the first one you see that runs.. it might bite you

Hilton

Ok - you also asked about common expenses.. here's a list off the top of my head for an S4 of common faults/repairs:

Fuel lines - 20-25 year old rubber fuel lines are a liability. Change them ASAP if not already done by the previous owner.
Timing Belt job - belt, rollers, water pump, cam gears, oil pump gears/seals, crank gear
Intake refresh - gaskets, o-rings, vacuum lines, knock sensors, oil breather hoses, throttle switch, possibly also ISV and hall sensor
Torque Tube bearings - three cheap bearings, but they're a bugger to get to. Also worth doing torque converter bearings at the same time on an auto.
Ignition electrics - plugs, wires, distributor caps/rotors. The other parts (coils, ignition amplifiers etc.) are pretty robust
MAF Sensor - the hot-wire Mass AirFlow sensors age, and have a useful life of maybe 10 years
LH failure - the Bosch LH 2.3 fuel ECU is a common failure and by now many S4's need to have a rebuilt one fitted Failure can/will strand you, sometimes a few hundred k's from home.
Shock absorbers - the fatory original Boge are no longer made, but Bilstein have some nice ones which were also fitted as an option on 928's from new (Sport Suspension option) and bolt in.
Engine Mounts - the hydraulic engine mounts fail leaving the engine sitting on the cross member - this means all vibrations from the engine are passed straight into the body. New mounts makes the car a lot smoother to drive. While changing engine mounts, often people take the opportunity to change the sump gasket as it can be done with the cross member out the way.
Steering rack - rebuilt racks are readily available, but not cheap. Replacing the rack is also a change to replace the worn rack bushings that mount it to the cross member, and also the tie rods, or at least the outer tie-rod ends.
Fuel pump - these are a relatively common failure.. they seem to last 15-20 years, and if your prospective 928 is on its original, chances are it'll crap out on you going over a speed bump a little fast

Search here on Rennlist for info on all these - there's plenty of posts, tutorials etc. on them, and all can be done by a competent DIY'er. Check this site for write-ups of a few of them to see if you think you're up to it. If you're paying someone else to do the work, the above will set you back a *lot* of money.

Beyond that, you'll pretty much have a very nicely driving 928, and the biggest remainign issues will be cosmetic.. which is major $$ to put right. So if you plan on keeping the car and doing all the above to it, start out with one that has a great interior and paint!

axis of evil

The rusted out XJ with a 3 speed is starting to sound like a bargain.

WallyP

The most important thing of all - if you can't/won't do your own repairs and maintenance, you can't afford to drive a 928...

While the "expected" repair lists that you are given here truly are things that might need to be done to a purchased 928, it is not at all certain that you would need to do all of them.

The minimum would probably be:
Purchase the Morehouse CD set.
Replace timing belt, rebuild tensioner, check everything in the belt system very carefully.
Change fluids.
Check for engine vacuum leaks, repair as required.
Check for HVAC vacuum leaks, block off failed actuators, eventually repair vacuum leaks.
Start checking and cleaning the electrical system connections and earths.
Fix any important/irritating problems.
Drive it.

Gary Knox

If you live in Auckland, there is a 928 Owner there who might also be of help. Eric McCall by name. Doesn't post much on Rennlist any more, but if you want his e-mail address, contact me via e-mail or PM.

Welcome to the 928 enthusiasts group if you buy. It's a great community.

Gary Knox
928 Owners Club charter member and current treasurer
join here: www.928OC.org

PS: I'm 73, and have owned six 928's over the past 13 years. Currently two.

Black Sea RD

I have to say probably one of the most important things to do is to research thrust bearing failure (TBF) on this 928 list and become familiar with it. Then during the PPI and if buying an automatic 928, have the mechanic check the crank shaft end measurements a few times.

It was mentioned above by Hilton but it's such a catastrophic event when it happens, it bears mentioning again. I would have to say bent valves after a timing belt failure would be easier and less expensive than a TBF engine failure.

Good luck with your search,

Emboss

FYI, I'm in Auckland, though I probably won't be too much use ... my 928 has been sitting in the garage far too long, waiting for the real world to get out of the way enough to have time to do the TB/WP job

mpesik

It can be a bit of a money pit.

So long as the expendetures are spread out, you'll be be rewarded with a fine automobile.