mark kibort

I raced an engine to 175,000miles and 40,000 miles of that was when it was committed to a race car. when the motor came out the bores were perfect. It might have needed a re-ring, as compression was in the 120psi per cylinder, but that could have been valves. the 928 engine is incredibly durable. usually, the headgaskets and accesories are what go bad. once they are all replaced, you basically have a new engine. drive it until you have a problem!

pcar928fan

300k miles... easy...

928SS

and at the other end of the spectrum - with only 135k mine needed an OH, was leaking oil like the exxon valdez and compression was off several cyls... in fact, all the gaskets and rubber parts were disintegrating/hard/cracking, tensioner was a mess, the oil pump gear was scored, the bores were scuffed/had a nasty ridge at the top and the crank was worn. but it had the KS pistons and it probably wasn't treated real well before I "saved" it. (based on most of the PM nonsense that had to be re-repaired).

but that was the good news. the bad news is that when all you have is a bare '85S block begging to be bored out just a little more than stock, it's a slippery slope when you start hitting the WYIT's along the way. course it'll be a hoot to drive

mcholdfast

John Pirtle told me his just turned 233K last week. I'm pretty sure it's his daily driver. They just need to be driven and maintained.

Whitesands

got 287k on mine and not planning to touch it yet apart from what should be done service wise.

Andre Hedrick

Well for the 16v, I am 900 miles short of 200K

Ron_H

My '86.5 had about 120,000 on it when I got it almost seven years ago, and now it has about 210,000 "brisk" miles and two or three trips across the US and back. I put in a quart of oil about once every four months, but I know there is some oil leaking from the pan gasket. The mystery is water loss. I put in about two pints every month, and have been doing it for more than a year now. The amount is slowly increasing. I would have thought that if the head gaskets are going they would have failed big time by now. Not so, and the engine runs strongly just as when I got it. Energizer rabbit motor. And, though I may not beat it into the ground as Bill does, (Sheesh! Don't invite him to your house or your neighbors will call the police!!), I don't baby it. There is no water in the oil. I haven't checked the transmission oil yet for water. I just can't figure out where the water is going. The cap holds pressure too.

My belief is that maintenance is part of the price of ownership. If you buy a new car and drive it four years and do nothing at all during that time and then expect to get your money back, you're not being realistic. As was pointed out to me by Marc Thomas, the 928 offers supercar performance even today that would cost six figures to duplicate if puchased new, for a price that is relatively ridiculously reasonable. It is not a Honda.

Personally, I plan to rebuild and restore my car completely soon and spend more than it is worth to do it. Then drive it another 200,000 miles if all goes well and I am lucky. If a Peterbilt crushes it, I won't get my money back, but until then I will gamble that will enjoy more pleasure and safety than most people can ever imagine. I have a friend who buys a new Honda every ten years or so, and brags at how economical it is to own and maintain. Well, she's right about the actual dollar amount but how she stays alive and keeps from falling asleep at the wheel is beyond my comprehension.

UKKid35

I have 210k on mine. I did a top end rebuild 45k ago, but that was due to cam belt failure caused by deferred maintenance and ignorance on my part.

Another way to kill a 928 auto engine is thrust bearing failure as mentioned earlier, and finally head gaskets can fail when coolant changes are skipped.

So basically if the engine is well maintained, it will probably last.

tombtaylor

my 87 S4 has 215k miles runs fine....I'm lookin for an engine "just in case"

dprantl

213k miles on mine. Last ~40k miles of those supercharged.

Dan
'91 928GT S/C 475hp/460lb.ft

david928

My odometer stopped at 107k. I estimate total mileage about 150k. It's still a teenager, and hopefully will last many more years, if I take good care of it.

Ron_H,
I had the same problem with coolant loss. It turned out to be a small crack in the plastic reservoir. It was leaking steam when hot and under pressure, but I couldn't see any drips. They cost about $150 and a couple of hours to replace.

Ron_H

Thanks David. I'll check that reservoir for cracks, but I had assumed that it would not hold pressure if any cracks were present. I certainly haven't been able to detect any other water leaks anywhere else.

Imo000

From what You wrote, I'm gussing that yours must have either really over heated, blew a headgasket and was not cought on time and/or it ran out of oil at some point.

Dennis Burford

I have 150K on mine now. Bought it with 135K, had it it tested with excellent compression/leakdown results. I'm betting on 400K miles for the motor if you take care of it. My only worry at the moment is getting the AC working before the warm weather comes.

928SS

when I changed to mobil 1 synthetic from dino oil it started leaking oil. later I read changing to low viscosity synthetics is bad for many old gaskets, my bad.

low compression was from scored walls/worn valves/seats.

the KS pistons were only produced for about 9 months/during a supplier strike, and apparently didn't compare favorably to the ferristan coated mahles which seem to last forever.

my guess is they knew it all along & switched back as soon as they could get the mahles. can't tell a motor has them w/out tearing it down, AFAIK. only found in some 85/86's I think.