Wisconsin Joe

So Greg is working on a 78, doing a 'get it to reliable' job, not a restoration.

https://rennlist.com/forums/928-foru...arly-78-a.html

Part of the job is to make it a 'daily driver'. So it has to be reliable.

Shawn Stanford popped in and compared the reliability of his 928, to an 01 Boxter purchased for 'lunch money'. And suggested that the ECU & fuel systems that are as old as the 928s can be problematic. So he is looking at an LS swap to make the 928 'reliable enough' to do cross country trips.

NOTE: I am NOT ripping on Shawn. I don't really agree with his rationale, but he raises a really good question.

However, it's a really complex question.

Part of it is that there are 4 distinctly different 928s.

OB - CIS injection, green wire ignition. (includes Euros through 83)

Early 80s US - L-jet & green wire.

S2 & S3 - LH 2.2 & EZF.

S4, GT & GTS - LH 2.3 & EZK (later models include the ignition monitor too).

Each setup has it's own pluses & minuses.

CIS is pretty reliable, as long as it's running right to begin with and kept clean.

L-Jet is pretty reliable. The computer almost never fails.

Green wire is good too, as long as the green wire is in good shape.

LH 2.2 is solid. EZF is too.

LH 2.3 has a known failure mode.. But the boxes are rebuildable with better, more reliable components. EZK is pretty solid.

Most of the mechanical stuff (drivetrain & suspension) is reasonable reliable, but it ages & wears.

Last, but not least is the electricals. The wiring in these cars is old. But replacement harnesses are readily available, although not cheap.


Soooooo...

Do you think your car is reliable? (what car do you have?)
What have you done to make it so?

If not, what would you feel is needed to make a 928 (either your own or the 'average' one) reliable?

And what do you consider 'reliable'?

Drive it most days, but not terribly long distances?
Drive it a couple hundred miles without any worries?
Drive it across a couple states?
All the way across the country?

To answer my own questions, I have an 85 Euro S2. It had a TB/WP & most of an intake refresh and few other 'odds & ends' done by the PO at a Porsche dealer, by a factory trained 928 tech (now retired) not too long before I got it.
I consider it reliable enough to take anywhere, anytime.

I took it from Wisconsin to San Francisco back in 14. No problems. Awesome trip.

I routinely (alternating weekends in the summer) take it 120 miles each way to Racine to go jump out of an airplane. I've had it die on the side of the road twice due to bad relays (FP & EZF). I carry a spare as an essential part of my 'kit'. Replace & on my way.4


Current long term plans include pulling the EZF & LH boxes and having them rebuilt as a preventative measure. Also the injector upgrade that Greg offers. Engine pull for a full reseal & Head Gaskets are on the horizon.

SeanR

Mines been my daily driver since 2006 and besides leaving me stranded 3 houses down from my house with a failed fuel pump, it's pretty much been dead reliable. Granted I was always tinkering with it to keep it so and it's slightly modified. Keep up on the maintenance and you won't have any issues.





Oh wait, the trans left me stranded on Christmas Eve one year, leaked out all the fluid and burned up the clutches, that was a biggie but it had 200k on it. Had another trans installed the day after Christmas.


Key is when something starts to crap out, fix it.

Jason89s4

My definition of reliable: Starts every time hot or cold, not afraid to go around town, sit in heavy traffic or take a 300 mile trip. A cross-country trip without a support vehicle is "beyond reliable", if that makes sense. (I had my '10 Sequoia strand me on a road trip when it was 3 years old due to an ignition system issue, so everything is relative.)

All things equal (well maintained, all vital systems operating) I'd probably pick what you called early 80's US car (L-Jet and Green wire) as the car I drive with the least concern about reliability. The AFM is pretty much bullet proof, green wire/ballast ignition as well. No worries about LH, EZK, amps, CPS, etc.

I love my S4 and it rises above as far as comfort and power, and I drive it regularly. But the reality is that is has many more 30-year old cutting-edge systems on the car that could go wrong, be harder to diagnose, more expensive/harder to source parts. Just my two cents.

Assuming they were all on the ground and "ready to go", and I was told "you must pick one and drive right now" from Dallas to Chicago (two days) I'd pick the '84 5spd. (Pack a green wire, relays and fuses, bottled water and some sandwiches and I wouldn't worry about a thing.)
-Jason

928cs

http://www.porsche-928-expedition.com/

And the work involved is explained here:
http://www.porsche-928-expedition.co...ion-de-la-928/

If I remember well, they have only had a problem with a door window motor and fuel pump (stones in the fuel!).

FredR

Everything has a half life and understanding this is key to avoiding reliability problems.

I have my own perceptions of how long things should last and thus when the likelihood failure starts to go down the slippery slope. My 1990 S4 LH failed around 2000- 10 years old. My 92 GTS LH unit came from a 90GT is currently 29 years old and probably a prime candidate for failure of the fuel pump sub board. I have the original GTS LH unit as back up so if the currently fitted unit fails I can extract the PEM and fit it to the back up unit reasonably quickly. I hope to fit a new PEM shortly so that I have a "drop in" spare as it were. Bottom line if you can carry a spare LH unit the most likely failure point is eliminated- that or get your currently operating unit to John Speake for a rebuild before it goes south.

Once the LH problem is covered I believe the S4/GTS can be configured to be very reliable. The aspects most likely to leave one stranded are the rubber hose for the in-tank fuel pump and water pump impeller mounting. Change these items out every 10 years along with the CPS and knock sensors [while you are at it] and you should have a very reliable machine.

Other things can fail but the LH, CPS and water pump are the items most likely to leave you stranded.. Other things like the engine wiring harness degrade but do not fail suddenly and they do it because the owner was not diligent. Knock sensors also fail after about 10 years but the car will still run. Same for the fuel pressure regulator and dampers. The MAF is probably good for 15 years and is more likely to degrade than fail outright as are the ignition leads. Change out these items after a reasonable service life and keep the old ones as back up spares.

Neglect these things and a breakdown type failure is more or less guaranteed. In 20 years of ownership I have never had a coil, spark plug or fuel injector fail. The only time I was stranded a few minutes after leaving home was when the in tank hose failed and a lump of rubber jammed the main fuel pump. A little strainer on the pump inlet would have stopped even that! Removed the main pump, reversed the current and the pump spat a little chunk of rubber out.

Needless to say regular maintenance on top of preemptive work on the above and you get a very reliable machine. I dare say there will be other items I have overlooked but not many.

hacker-pschorr

+1
As someone who works closely with a couple local repair shops, I see all levels of "reliable". I've seen one too many, very new automobiles, that have left people stranded due to some minuscule electrical problem.

Examples:

• BMW door open / closed switch (just like the one on a 928 that triggers the interior lights) failed on a new M5. Computer thinks the door is open and locks the vehicle in park. The family was in GB from a couple states away, it was Friday afternoon and the parts were not in stock locally. Ruined their vacation.
• Friends Corvette, the gas pedal failed (it's an electrical switch, throttle by wire) and he was 1,000 miles from home in BFE. The local O'Reilly's doesn't stock those (pat attention to this one LS swap people....)
• Mercedes - doing a simple brake pad / rotor job. First time pushing in the pedal to set the pads, pedal goes to the floor like normal but this triggered a brake failure warning - locked the brake system. Had to be dragged on a trailer and brought to the dealership to unlock. The non-factory computers don't have access to that system.
• Many small parts, like a window switch, cannot just be installed in most new(er) vehicles without some kind of factory software or clone computer. Most parts (if not all by now) must be coded to the VIN of the ECU in order to work.
• New(er) Audi towed in, engine died. Assumption would have been timing belt broke, but this was a chain motor and even that was in tact. Come to find out a camshaft lobe rotated - that's not a typo. Many new(er) cars have hallow shafts for camshafts with lobes pressed on. Lighter rotating mass & cheaper to make. Well this one rotated and smashed a valve.

Don't get me wrong, there are advantages to new(er), but that doesn't automatically guarntee reliability.

928's are incredibly simple machines by comparison to anything built in the last 20 years.

Make a list of things that cannot be "fixed" on the side of the road, like a failed LH / MAF and make a priority of having those rebuilt and even carry as spare. Get an AAA gold membership (or towing with your insurance company, State Farm is cheaper & better than AAA) and enjoy the car.

Taguid

My first 928 (daily driver) was an 87 S4 108k miles venetian blue I got in 1999 (12 years old) and sold in 2003. I had no idea at the time of it's reliability or any of the required maintenance ( timing belt, water pump, TBF) but when I purchased it had just gotten a timing belt replacement. I used it as a daily driver for 4 years and all I did was oil changes. I purchased a 91 S4 90K miles in 2016 with unknown maintenance history from Charleston, SC and drove it to Baton Rouge, LA without incident. Since then I've done loads of maintenance. Too much to list here but I have touched just about every system in the car. I would not hesitate to use it as a daily if necessary. My avatar pic is from the first time I've removed the engine and I have done that on 4 other occasions just because it was easier to what needed to be done with it out of the way.

voskian

My 1991 GT was bought 7 years ago with 24k miles. It had been stored for 12 years , essentially off the road. I initially did TB, WP, tensioner and all fluids, cleaned the grounds. As preventative maintenance, I sent out the LH and MAF for rebuild. Replaced, fuel pump and filter and swapped out the shocks. Upgraded the wheels to 18” and new tires. Drive about 4K miles per year (and car is off the road for 5+ months each year here in New England). This last spring, knowing I would be doing a lot of long distance driving ( Camp 928, Rendezvous 928 and Frenzy) I decided to have Dave C (worf928) do an intake refresh, fuel lines, vacumn lines, hoses, TB, WP, tensioner, rotors/caps, injectors cleaned, in tank FP repair and complete fluids. It didn’t need all that, but while the intake was off replaced knock sensors, tps, Cps, and all temp sensors.

I also am back and forth between Maine and Mass (200 mile round trip) many times all summer. I have clocked over 4000 miles this summer and not a hiccup, even the AC that I had addressed 7 years ago still blows cold! I still have Frenzy coming up in Sept so I’ll have covered three long distance events, and consider my GT as reliable as any car I own.

I think any car car can be made reliable as long as the owner spends the time and $$ to keep up with maintenance.

GT currently at just over 51k miles..

( I hope I didn’t just jinx myself!)

Speedtoys

"ECU & fuel systems that are as old as the 928s can be problematic."

I just don't understand the context of this, at all.

An older design where no plugs are weatherproof, and will oxidize together requires "maintenance' once every 10-20yrs, and maybe your LH in a later car will die, someday..every 25-40yrs.

hacker-pschorr

Yea, compare the fuel system of a 928 to any GMC truck / SUV in the last 30 years. You are in BFE and the fuel pump dies, easy peasy, every auto parts store has them in stock. But then you find out the tank need to be dropped, all of the fasteners are rusty, the fuel lines cannot be removed without damaging them....... $3,000 later you are back on the road!!

Wisconsin Joe

It was Shawn's statement, not mine, but I do understand where he's coming from.
Not a design issue, but an age issue.

The later LH (in the S4s) is known to fail eventually. Some folks have them rebuilt proactively, anticipating that failure.

Even the more reliable LH 2.2 and the L-Jet boxes are subject to failure after a long time (the "25-40 years").
These cars are at or approaching the 'estimated mean failure time'.

My 85 is now 34 years old. As such, I'm starting to wonder if & when the computer will 'just quit'. That's why sending it off and having it rebuilt (most likely by Louie Ott) is something I'm pondering as an 'over winter storage' thing.

And Erik pointed out the 'reliability' (or lack of) in newer cars. A fun one he didn't mention is an issue with the Cayenne (05 - 10). They have wires running under the driver's side carpet. Some of those wires have 'splices' that are nothing more than bare conductors crimped together, then wrapped in cloth tape. If (when) the cowl drains get plugged, water comes in through the HVAC vents. It soaks the carpet. There is open cell foam under the carpet. The carpet can be completely dry, and a couple months can pass, and the foam underneath is still saturated (to the 'drips water when squeezed' point). The 'crimped & taped' splices then corrode (conductor pretty much disintegrates) and the connection fails. The car then gives all sorts of odd dash warnings and won't crank. The fix is to dry everything out and repair the splices. Been through it.

His comment about the overall simplicity of the 928 (yes, it was one of them most advanced cars of it's time, but that was a while ago) makes me think that a properly cared for 928 could be more reliable than a newer car.
The question then becomes 'what should be replaced (and when) before it fails?'

Obviously, the TB/WP, fuel lines, maybe brakes & coolant lines.

But what about the computers? Fuel pump?

And to be clear, I don't pretend to have all of the answers to this.
I have a few opinions and am curious what other folks think.

John Speake

If you own a 30+ year old car, then as well as a good routine of regular maintenance you need to also to keep a proactive preventative maintenance schedule as well. There's plenty of expertise on here to identify many items that will fail in ways not predicted in the service schedule. After the first ten years you just have to be wider ranging in the work you can expect to do each year.

It might be an idea for us all to pool our recommendations for items that should be carried out at intervals of (say) every 5 years from ten year point. Then we can see what deferred maintenance we haven't carried out from the check list since year 10.

The only times I have had trouble with my car was soon after I bought it and entrusted it to the local Porsche OPC. Since then
thanks to the help from this list I managed to maintain it myself, with no unscheduled time off the road.

The earlier cars do have less electrical gizmos which can all cause trouble in the later cars.

GT6ixer

+928. IMO the discussion on whether a 928 can be made into a reliable car begins and ends with Philippe's car. That car is 99% stock. Now what you need to do to a 928 to get it to that level is another question with thousands of different answers depending on the specif car and it's current state of being.

For me I bought a US model, '84 auto, 2-owner car that had sat in a garage un-started for 10 years. That was 3 years ago. I now have daily driven it every summer since 2017 and it only broke down twice. Once due to a faulty FI relay (which I should have replaced during the year one restoration). And once due to a leak from and oil pan fastener which damaged the alternator.

This is just a small list of the work done:

• TB/WP
• Fuel tank removal and cleaning
• Flushed coolant
• Oil change
• Flushed brake fluid
• New fuel pump/filter
• New fuel lines
• New heater valve
• New plugs, plug wires, rotor, dist cap, coil, green wire
• New starter
• New alternator
• Injectors serviced at WitchHunter
• New vacuum tubes
• Every rubber engine hose replaced
• Cleaned FI rails
• Cleaned intake plenum/spider legs
• New brake rotors and pads
• Complete disassembly and cleaning of CE panel
• Cleaned all ground locations
• Cleaned all fuses
• New relays (starter, fuel pump, FI)

Bill Ball

Terrible! My original trans only lasted 280K miles. I rarely drove the car over 150MPH for any significant distance (only a couple of times a year in open road races and only for a hundred miles each time and never over 170 or so) and I only did burnouts once in a while after I put on a supercharger. Eventually I had to replace the trans. You'd think it should last more than 25 years of careful driving. Pitiful.

The exhaust system fell apart when I hit an 18" long oil rig pipe. Tore the rear section apart and bent the trans cable. That meant I had to drive 200 miles stuck in 3rd gear with my torn up exhaust making lots of noise. In 3rd gear I could not exceed 120MPH. NOT ACCEPTABLE! I was embarrassed.

Oh, and then there was the time my LH failed on the way to work. It was only 15 years old. It took 30 minutes for a buddy to being me a spare and get back on the road. I was embarrassed to be 30 minutes late for work, but fortunately no one noticed.

Then the radiator started leaking around one of the side tanks during an open road race. I was traveling 150-165 MPH for 100 miles. I found green stuff on the side of the car after the race. I had to wipe it off and check the fluid level. It was OK, but I didn't like seeing green stuff on the side of my car. Even though it was a slight leak, it cost me more than $100 for parts and labor to fix the darn thing. Then it did the same thing 7 or 8 years later. Had to fix it again. So, I can't say the radiator is very reliable even though it hasn't failed again and is still in the car. Someday I might have to replace it. Shouldn't it last more than 30 years?

Then you have things that are supposed to fail but won't. I tried replacing the torque tube bearing at 200K miles. There was nothing wrong with them, but since it seems a lot of people experience TT bearing failure at 100 to 150K miles, I thought it was prudent to replace them so they wouldn't fail in the middle of nowhere. Tried as hard as I could with a pipe and 5lb sledge hammer to get the old ones out and they wouldn't budge. I had to put the TT back in the car with the original TT bearings. And they are still there now with no play in the TT shaft or noise. Why would Porsche make them so hard to remove? That's stupid.

Oh, and don't get me started on the oil pan gasket and motor mounts. I had to replace them at about 150K miles. I might have to replace them again sometime. NOT ACCEPTABLE! So what if every other car on earth with that kind of miles needs motor mounts and pan gaskets too. Porsche should have made them last forever.

Wheel bearings! I actually had to replace a rear wheel bearing at 150K miles. Seriously?

So you can see why I have only driven the car 230K miles since I bought it 20 years ago. It's just too much trouble for a car that's only 30 years old. One problem after another.

The real problem seems to be the car does better if you drive it frequently. What if I just want it to be a garage queen like many other Porsche nuts? I hate that seals dry out and things start leaking and sticking and malfunctioning if I don't drive it much. So, what am I supposed to do? Drive it every day? I guess I'll have to. Darn nuisance. I should buy a trusty Honda that doesn't mind being neglected and sitting for months. I hear they are reliable with the only problem being they are very boring.

beran earms

That is a great response Bill, perfect!