Falcondrivr

LOL! Have you hit 300K yet?

os993

Considering my car is a '95 (which was on the road end of '94), we're talking about a 16yr old car!! Hard to believe actually when I think my car is 16yrs old. Still looks great (folks tell me this and I wholeheartedly agree!) and the car has 135k miles. Strong as an ox with no problems, leaks, or issues. I track it less often these days, but a "once a year" clean out the cobwebs session is always in order to "clean out the valves" as they say.

I guess what I'm saying is that ANY car 10yrs or older is subjective to some wear and tear. Take my '97 BMW 540i with 125k miles. What a delicate, often has issues, car. It's a great driver, but much less solid than my 993.

Ed Burdell

These engines are bulletproof if you drive them hard. Let 'em sit, and issues arise. Mine's past 94K miles with no problems other than an annoyance leak at the timing chain cover. Had the valve cover gaskets replaced earlier this year. Disabled the brake pad wear sensors out last year - they go faster than the pads do. My passenger side headlight doesn't want to work right now, but that isn't engine related. Oh, and my oil cooler fan ballast resistor failed four years ago, so I just pulled the plug so the fan runs at high speed all the time, which is handy in the Georgia heat. No CELs or emissions test failures.

dryadsdad

Thanks. I'm unable to see much of a pattern of strange failures except repeated comments about 'wiring harnesses'. I never heard of one of these failing except after a fire so I consider it strange.

@Harry - any vehicle has outlier events. I was looking for a pattern of failure such as the SC had two - stud breaking / stretching and cam chain adjuster failing.

dryadsdad

Of course wear and tear. I didn't state my OP well. I was looking for a weakness that creates a pattern of failure. The early on SC's had drastic failures due to cam chain tensioner failures which would take the entire engine out. This is a 'pattern' failure due to design or manufacturing defect.

I asked since I was seeing so many posts about major engine overhauls occurring on relatively new engines - even if the vehicles are fairly old.

That said, a regularly used engine should last a very long time. Age affects the other than internal engine parts such as seals and interiors more than the valve guides or bearings. Frex, I had a 1978 Chevy pickup truck I ended up selling in 1998 with 250k on the engine. The engine had never been opened and AFAIK, it was fine. The truck itself was rough due to exposure to the elements. It was a daily driver. Of course that's a much less intense engine than in P-cars so I wouldn't expect 250k miles on a daily driver Porsche to be common, but it could occur if one wasn't 'on it' regularly.


I'm not sure I have a secondary air system because my car is a 94 or on the road in 94 but titled 95. AFAIK it's a VERY early 993. I thought I'd read somewhere that a few very early US bound 993's escaped w/o this feature. Is it an easy check? I don't know what to look for.

By 'drive hard' do you mean hard driving or regular driving? Ours is and always has been a Sunday and GT style use car. I can't see hard driving as assisting engine longevity, but regular - yeah, that makes sense.

Rinty

Everyone will have their own concept of what "hard driving" is, but my understanding is that you need to regularly get the rpms up good and high, after the oil is warmed up.

It would be very interesting to find out what the wear is, on the components. But you'd want to run it out to at least 400,000 miles first.

That dentist's 400,000 mile 3.2 Carrera engine, that was recently featured in Excellence, had no wear when it was disassembled.

Linnm

Secondary air didn't show up until 1996.(as did VarioRam)

matt777

I think most sports cars have a weak link somewhere. It doesn't mean that they aren't unreliable. I've got 74k on my 993 and it runs great. The leakdown results at 64k were very good. It uses about a litre of oil every 2600 miles and I don't baby the engine (lots of full throttle runs through the gears). The 993 is not a maintenance time bomb. A PPI with a proper inspection and leak down should identify the big maintenance risks. A documented maintenance history is very nice to have too. That said, I think you have to be able to spend some bucks, if required. The cars are 15 years old after all.

vincer77

'95s have secondary air injection (SAI). What they do not have is OBD2 that signals the fact that the ports are plugged in the form of a CEL which will result in a failed smog check.

From what I have seen and read, 993 are very reliable - and is one of the main reasons I decided to get one. I believe most of the top-end rebuilds were done to solve the SAI issue, which can be dealt with less severely - i.e. SAI flush. It is also interesting to note that 355s (also of the late 90's) had problems with soft valve guides.

Quadcammer

I call 100% bull****, not on you, but on the article and its findings. I don't care if he ran elk blood in it, the engine will have some wear on the cylinders, bearings, valve guides, etc.

dryadsdad

By no wear, I interpret that to mean no wear putting it out of spec.

2ndof2

My personal experience was the need for a valve job at about 85K. Should have happened sooner to meet CA emissions requirements but got a "favor" from the local P-car dealer that snuck me by emissions with a note to the principal. Did the top-end because several cylinders showed secondary air port blockage and my p-car dealer contact had left the company when it was time to get a new smog cert two years later.

When I finally had the job done, the car was still within spec on oil consumption, but certainly at the high end of range (only 700-800 or so miles before requiring a quart). Freshened everything up and put new piston rings in during surgery. The car probably would have been perfectly fine without new guides for a while longer, but mine seemed to be one of the unlucky cars where the wear was significant enough to clog up the works. BTW, tech said everything looked absolutely flawless inside and nothing that looked like it had bad wear. So I think its fair to say the bottom end on these motors are engineered very well.

If you are in the market for a 993, my advice is, buy a car that had a proper top-end rebuild not too long ago. That would be my first choice other than an extremely low mile car with an excellent PPI report.

Tango635

If your question is "how common is a valve guide replacement for 993s", I think you might get a better answer from a shop that does a lot of air cooled cars. They would probably be able to give you an idea of how common it is from model to model, i.e. SC vs Carrera vs 993, etc, then you can judge for yourself if this is something to worry about.

As a matter of fact, contact a few shops to get the best picture. You could contact Peter Zimmerman. He is a renowned Porsche master mechanic, had been working on Porsches for over 30 years, up until he sold his shop. Do a search on the 911 board here.

A leak-down test should catch bad valve guides. The problem has to do with an inferior material, not with a poor craftsmanship on any of the porsche air cooled engines.

Other than valve guide issues and SAI clogged ports, there are no other common issues to give you reason to go into a 993 engine. The 993 engine is very robust. From what i've read, I would put the reliability of the 993 right up there with the SC.

Tango635

If your question is "how common is a valve guide replacement for 993s", I think you might get a better answer from a shop that does a lot of air cooled cars. They would probable be able to give you an idea of how common it is from model to model, i.e. SC vs Carrera vs 993, etc, then you can judge for yourself if this is something to worry about.

As a matter contact a few shops to get the best picture. You could contact Peter Zimmerman. He is a renowned Porsche master mechanic, had been working on Porsches for over 30 years, up until he sold his shop. Do a search on the 911 board here.

A leak-down test should catch bad valve guides. The problem has to do with an inferior material, not with a poor craftsmanship on any of the porsche air cooled engines.

As far as I know, other than valve guide issues and SAI clogged ports (96-98), there are no other "common" issues to give you reason to go into a 993 engine. The 993 engine is very robust. From what i've read, I would put the reliability of the 993 right up there with the SC.

rsr91128

How?