Rich9928p

For 32 valve 928s check cam chains at 100,000 miles, replace cam chains at 150,000 miles.

worf928

I've added Wally's electrical conditioning on a 2 Year schedule (not reflected in the lists above yet). Thanks John!

There will be a number of sections.

Clean, rebuild tensioner. Idler rollers.

To all:

I'm not contemplating whole-sale duplication of the wealth of information that exists. My assumption is that when the schedule calls for a timing belt change that the owner will find the relevant documentation and determine based upon that documentation what is 'standard procedure'. For instance note, that the schedule does not list the water pump.

I'm trying to stay true to the purpose - a reminder system.

I also am not going to load up the schedule matrix with basic stuff like checking oil and tires and looking for leaks on a weekly, daily, or every-drive basis. I operate under the assumption that we do that anyway. And, for any particular owner, if not, my lists would be useless. Also, I don't want a 50-page document that burdens us. A few pages tops. Anyone who wants to go further - more power to'em!

To which part do you refer? Do you mean the plastic bushing for the release arm lever? (Not seeing a ball joint in the pedal system itself in PET.)

worf928

And the tensioner pads too!

AO

One I do every year is to clean and lube the sunroof. And one I've been meaning to do is to make sure the drain holes are clear.
Great List!

worf928

yes! yes! excellent.

I was just thinking the same thing today when I the thread about the car wash ("He needs to check his sunroof drains")

BUT, like a doofus, I didn't think of adding it to my list.

Thanks!

Keep'em coming folks...

pcarphanatik

I think you all would be very interested in Car Companion .

Check it out, should help you guys track all of your maintenance. I am using this open-source app for my 944 turbo, and it has really helped to make sense of 17 years worth of records

Doug Hillary

Hi,
Tails - you said;
"The later developments were by 'predictive maintenance', as we have seen with one member of the Renlist Forum giving us his reports on the analysis of the engine lubricating oil with regards to metal traces, water content etc. however, I believe for our car the planned maintenace approach is best except when those of us that have the fault diagnostic system used by Porsche Centres of by the one that John from JDS Porsche has developed."

I commenced Used Oil Analysis (UOA) on my car a couple of years ago in response to Marc from DEVEK promoting 3k oil changes. It was NOT intended to be "predictive" - it was done to CONFIRM Porsche's time & distance based recommendations which it did of course with a wide safety margin

I knew it would of course having been involved in these areas - both Lubricant analysis and formulation and Programmed Maintenance - for nearly five decades

Modern high quality lubricants when used in our cars can safely have their drain intervals extended
but I have never recommended this here. If it is part of anybody's plan with a 928, UOAs should be used

Many Euro car manufacturers are moving quickly to 50kkms (30k miles) oil change intervals and using inbuilt Oil Sensors to go there and further

USED OIL ANALYSIS CAN BE USED TO MONITOR WEAR IN CRANKSHAFT THRUST BEARINGS TOO AND SHOULD BE - BY EVERY 928 AUTO OWNER!

It is another reason why I will continue to do it

This is a very meaningful thread and of benefit to all - thanks!

Regards

IcemanG17

One thing I didn't see listed is the vaccum acutators/lines in the HVAC system...they seem to fail quite routinely with age....might be worth the effort to change them all at once (they are cheap, about $100 or so for all 4) while you have the dash off!

Also don't forget the heater valve!

worf928

Would anyone like to chime in with some ideas of the expected lifetimes of these components? I have no good data on them.

2/3s of my fleet does not have either of these issues. Heater hose has not (yet) exploded on either and the vacuum lines are ok. The other 1/3 has ZERO climate control and the heater hose has been removed due to a leaking heater core. Although the removed hose was not original and thus indicates previous a previous burst mode.

worf928

Doug, let me start by writing that I (and I think others) are truly appreciative of your effort and reports to us resulting from your UOAs.

I would seek clarification of the above. Let's stipulate to UOAs being a very, very good idea. However, I have used your UOA reports as the basis for two things: 1) using the Porsche-recommended oil change intervals in the list above and 2) changing my personal oil change schedule from twice per year (roughly 3000 miles between oil changes) to once per year (roughly 7000-8000 miles.) Both of these are, of course, in conjunction with fully synthetic oil - either Castrol 5w-50 or Mobile 1 15w-50.

Do you believe that a one-year or 15,000 mile (whichever comes first) oil change interval with appropriate synthetic oil is OK as a default recommendation? Or do you believe that this interval is only appropriate when used in conjunction with UOAs?

Doug Hillary

Hi,
Dave - in answering your question;
"Do you believe that a one-year or 15,000 mile (whichever comes first) oil change interval with appropriate synthetic oil is OK as a default recommendation? Or do you believe that this interval is only appropriate when used in conjunction with UOAs?"

1 - I believe that the Porsche recommended OCI of one-year or 12,000 miles is easily attained in a normally driven 928 when using a OEM filter (or perhaps a M1 synthetic media filter)
2 - In my tests it is very evident that if you use a good quality Porsche Approved oil, 15,000 miles is attainable without a problem too. The Approved oil WILL be a quality synthetic and suitably endorsed on its container with "Porsche Approved" to enable this to become a default recommendation
3 - In regard to 2) above I would do a UOA at the 10k miles point initially until the "health" of an individual engine and its treatment of its lubricant is known. There may be no need thereafter
4 - If you want to monitor thrust bearing (and other component) wear I would advise;
a) a UOA every six months in a normally driven 928 Auto
b) a UOA after every extensive track day in a car that is "tracked" often
c) if either a) or b) show elevated copper, lead or aluminium levels a further test will be needed
d) if the levels have NOT "spiked" to very high levels and in unison the further UOA should occur within 1k miles to determine the elevation's trend
e) if the levels HAVE spiked to very high levels and in unison an immediate mechanical inspection is probably justified

The UOA results from my car provide a great wear metal baseline for all 928 engines

One reason why the oil has an "easy ride" in a 928 is the engines's high core temperature (90-95C)
which keeps the oil in an ideal operating temperature band. Other reasons are the large sump capacity, the thermostatically controlled oil intercooler and the excellent oil pressure/flow relationship when using the correct viscosity lubricant

If a 75C coolant thermostat is used the oil (and the engine) will take longer to reach the core temperature if it ever does and especially in very low ambient temperatures. This will be harder on the engine lubricant keeping it more viscous and take longer for it to activate all of the anti-wear and other additives in its formulation

Regards