1999Porsche911

Did not know about this. :oops: Thus, I agree that Type I revs are kind of irrelevant upon buying a vehicle. Nice one about the 0W40 :lol: Despite all advances in engineering and lubricant's quality, engines are still subjected to great amounts of "friction" among all its moving parts. That's one of the reasons why high working temperatures are reached! Heat from friction is just being dissipated. Physics on the other hand, tells us that, the faster one part is being frictioned against another, the greater the friction and the wear. At high speeds friction is proportional to v2 or even v3. The non-linearity of this relation between wear and parts velocity means that doubling the speed can have a four-fold impact in wear! That assumes that the engine's components are creating the friction without bearrier. Beleive me, if any moving part of your engine was touching another part, even letting the engine idle would destroy it in a short time. Hense, the need for a better oil and oil pressure than Mobil 0W40 can provide. Using the formula above, where "v" = negligible, the result would be slightly less negligible.

I think you mean that you can have very serious type II over-revs and not so serious type II over-revs. I agree with you. I dont know the type II rev limit, but lets assume it is 7280 rpm. If you make 7281 rpm it wil be registered as a type II over-rev as would be a 9000 rpm, and I agree +1 rpm is not that serious. I think this is one of the reasons why Porsche decided to increase the number of intervals where over-revs are classified (6 types in 997 I think). So I would say that an abused engine has, for sure, type II over-revs. On the other hand, having type II over-revs does not necessarily mean that the engine was abused. Nevertheless, as a buyer with free will, I will not take risks and I prefer to reject a good engine than accepting an abused one. This implies rejecting cars with engines with considerable type II over-revs! So I think the procedure is correct from a buyers perspective, of course! In what concerns Type I over-revs, let's do this experiment: 2 perfectly equal engines run for 100,000 km. Engine 1 is pushed to the redline in each and every shift. Engine 2 has a more "calm" usage pattern and never reaches, lets say, 6.000 rpms. Engine 1 thus has 300,000 type I ignitions and engine 2 has zero type I ignitions. Which one would you choose? I've no doubts about it! Theoretically at least, engine 1 has been subjected to greater stresses and is for sure more weared than engine 2, or not? Just my 5 cents ;) The type 1 over revs would not play a part in my decision. Since the computer can only log a maximum number of type 1 revs before the counter resets anyway, how do you know the car that shows only 2 is not the beginning of the 3rd or 4th count cycle. :D How hard a car is driven does not, by itself, translate into additional wear of the engine. That is, unless you are using Mobil 0W40.

The over rev count is an artificial number as it pertains to the safe rev limit of the engine. Porsche established a limit to the engine rpms far below the safe and obtainable engine speed. The 3.4 can easily obtain rpm of 7800 if the rev limiter is by-passed. Additionally, I disagree with you when you state that the number of type 1 ignitions can be used to determine whether one engine is better than another. Bouncing off the rev limiter with every shift does nothing to harm the engine since it is an electronic limit and not a mechanical one.

Yes, it can be very bad to simply let your suspension hang free. If, for some reason you must do so, at minimum, grease up the shafts on the shocks to prevent them from rusting and remove the wheels to reduce weight on suspension components. Any rust will greatly increase your chances of having leakage. It is best to lift it by the suspension.

For the price of a new MAF you can get a good scanning tool which all new car owners should have. Using the tool will tell you if your MAF is bad or not rather than acting like a typical Porsche Technician and replacing parts until you find the problem.

Okay - one thing to get straight - the winter spec (0w-40) refers to viscosity when cold (there's more to it, I know). The 0 weight is thinner than a 5 or 15 weight when starting the engine at, let's say, room temperature (although the spec is at 0 degrees celsius). This means that it also circulates more quickly and covers the valve train, etc. regardless of the temperature. Hence, a thinner oil can reduce cold-start wear moreso than with a thicker oil which takes more time to penetrate and circulate to and through the tight engine tolerances. I used to think you'd be crazy to run "thinner oil" but after reading lot's of threads, books, and conducting what I'd call "independent research" - I'm sold on using the factory fill in these engines. 5W-40 doesn't give any better warm-weather or high-temp protection than 0w-40, and it offers less cold-start protection. So 'splain it to me Lucy - why use thicker oil unless you're spending a day at the track, running hard from dawn until dusk and not letting the engine cool down appreciably??? Not inviting flames - but interested in any intelligent reasoning. Thanks much. I had my numbers wrong. the lower first number is the thinner, duh. considering what you've mentioned, I'll likely go with the 5w-40 at next oil change just on general principles. question: why would Porsche list the 15w-50 in the 2003 owners manual? why not have that multi-vis oil still on the approved list? thanks, j It costs the oil manufacturer alot of money to get their oil recertified for the approved list. You'll most likely see a shorter list of approved oils as certifications expire (usually around 3 years) and many of the manufacturers choose not go through the expense of validating their oil.

At the risk of starting another "oil wars" thread :oops: The December 2007 Porsche approved oils list doesn't have anything more viscous than 5W-50 as far as I can tell. Given that cold starts are a major wear issue on any engine - the "Mobile Water" seems like a good cold start oil, and the rating to a 40 weight when hot should provide ample protection - given it's the factory fill also. I've tended to run heavier oils when given the option in the past - because I also tend to drive hard. However, after reading and understanding the issues with engine tolerances, and multiple service duties (like oil acting as a hydraulic fluid for variocam), etc., I'll stick with the Porsche approved oil list. You can find it under the 996 TSBs if you're a member, and search for "Oil." Oh, and I received a remanufactured engine, courtesy of the Porsche CPO warranty, after my intermediate shaft (bearing) failed. I haven't seen 15W-50 on the list. I used Castrol 5w-40 Porsche approved, since where I live I don't need to go down to the 0W. I don't think I have ever seen 5W- 50 being sold off the self! Maybe available on the net. Kevin, I checked the TSB and you're right. but 15-50 is noted in my owners manual. I live in a cooler climate area, but travel to high temp inland areas often. that's why I'm using the 15-50. seems the heavier 5w would be a harder cold weather start. I used Castrol 20-50 in my SC for years with no problem. would you recommend a different oil at the next change? Cheers, jl A 50 viscosity oil is best for your Porsche and 15W or 20W is perfectly fine unless you are regularly starting your engine when the oil temperature is below freezing. For some reason, many educated people here argue that 15W50 or 20W50 are too thick an oil to get to into the "tight tolerances" of the engine. I would love to know just one oiled area of the engine that has any tigher tolerance than any high compression engine from 40+ years ago. For those who rely on Porsche to tell them what is alright to do, 5W50 is approved and if this oil has no problem going through the engine, then neither will a 15W or 20W oil. Porsche continues to factory fill their TIGHT engines with Mobil 0W40 and many of these cars burn gallons of oil between changes and leak from various orifices. The use of 0W40 from the factory is primarily due to substantial subsidy to Porsche from Mobil as well as Porsche's need to meet epa and other regulator's demands for better fuel economy. In most cases, moving to a better oil reduces or eliminates both oil burning and leakage as well as provides better shear protection, especially at low rpm torque conditions, better lifter operation at both idle and near redline, etc, etc.

Good ideas, but the nature of having a 90 year old garage surrounded by woods, meadow and farmland means there is an endless supply of mice. A longer term solution is new garage, but today I need info on access points to my car! If you have mice in your garage, you are not going to stop them from gettiing into the car, short of completely wrapping the car up. They will get into your engine through the tailpipes, into the passenger compartment and eat your seats, etc, etc. Sealling the access points to the garage is your best bet and include traps in the garage to catch them if they do get in. Remember, mice only need an openning of about 1/3rd their body size to gain access. It's a pain to do but is doable.

Mice can actually get into your engine's cylinders. As suggested above, keep the mice out of your garage. If necessary, throw down a few of those traps that the mice will stick to if they do get into the garage.

Anything BUT Mobil 0W40. Try the Syntec 5W50 or, preferably, Mobil Exended Performance 15W50.

At your next oil change, try another oil.

What kind of supercharger? Possible areas where oil leaks can occur would include the oil sending unit and from around the spark plug tubes. The cam cover may also weep oil. Cause of "spraying" oil due to intake boost would be surprising since boost does not enter the crankcase. (or at least shouldn't). I would confirm exactly from where the oil is leaking and go from there. Also check your oil filter for proper seal.

A note on tuning your engine. Regardless of what you do, whether it is software or exhaust, etc, make sure you verify what the engine parameters are after the mods. Particularly timing and A/F ratio. This can be accomplished by using a scanner and taking a reading of the sensors at various engine loads and speeds. You should also record your warm engine vacuum reading at idle with A/C off. Unfortunately, many backyard tuners as well as professional tuners, make changes and later find out that their mods make the engine run outside safe parameters. It is always good practice to log the readings of all sensors prior to making any changes at various engine loads and speeds. Regarding the specific mods mentioned; a more free flowing exhaust will cost you lowend power but may free up engine breathing at or near redline. A freer flowing air filter, assuming it draws air from outside the car, will give you some improvement in throttle response and some more power, but nowhere near the additional power many companies claim. Biggest benefit of an open filter (cone), is the change in engine sound. As for tuners, this will get you the most power improvement but at a substantial cost. Tuning of an NA engine simply involves timing changes as well as may include modifications to the fuel maps. Bottom line is that most of them result in only moderate increases in power and some obtain the added power from leaning out the engine, which, in most cases is safe for the 996 since the factory program is set to run slightly rich. Like I said, log the readings of all sensors on your engine BEFORE making any mods. To make significantly more power, you would need to go with forced induction or chemicals to increase oxygen levels in the cylinders.

OK, Thanks for the info. I have a stock engine except for K&N intake and Sport exaust. (2001 996) but it seems when I use the off the shelf (NOS brand Racing formula) octane boost, 10 bucks at Bennet auto, it runs better (smoother and more guts). That is why I started doing research on octane boosting. But if you think I will not see much more improvement, why hassle with chemistry !!! It's all in your mind. That, so called octane booster gives you an increase which is almost immeasuarable.

And wouldn't it be somewhat idiotic for Porsche to design a car that didn't have enough parametric mapping range, A/F mixture and/or timing adjustment, for use in a country/region/continent where premium fuel is often not available...?? Your right and premium is not available in all areas, that's why Porsche says you can run 91. Droping 3 points is ususally not an issue, but 6 can be! Sensors are not going to tell you anything other than they are working and depending on the one you have you will see what the outputs are. Will not tell you the combustion profile! You have no clue by looking at a scanner and seeing if the map is at it's lowest limit unless of course it has the map download capabilities. As I said it's all speculation! You have to look at he actual maps! Until someone can provide the actuall map parameters, I would not stand by that 87 can be run without any damage. But then again it's your cars do what you want! With over 11:1 even with low ambient temps the combustion temps are higher. So lets not go that route. Yes i have a scanner. And, like I said, it is NOT speculation. And, in fact. your scanner CAN tell you exactly what the maps are doing. The DME not only adds fuel to the engine with each signal from the knock sensors, but retards the timing by approximately 4 degrees each time all the way down to 8 degrees advanced under load. It may be speculation to you, but is a fact to those who know. Low octane by itself does not always cause detonation, anyway. Additionally, ANY early detonation WILL create noise that will be picked up by properly functioning knock sensors, whether you hear them or not.

An octane of more that 93, which is readily available in Flordia, will not increase performance or give you better gas mileage on a stock engine.

It is NOT speculation. This is a fact and is easily proven by monitoring your sensors. Spend some money on a scanner and have yourself a look. As a matter of fact, if the ambient temperature is cold enough and engine temps are low, timing is often not retarded, even when running 89 octane.

The engine will detune to accomidate the lower octane. Timing will be pulled and fuel will be increased. Other than decreasing the performance of the engine and using more fuel, you can drive the car forever on 87 octane without any damage to the engine.

Of coarse all lifters can make noise, regardless of engine type or manufacturer. I highly doubt your problem is a faulty lifter that requires engine rebuild. Although a possability. there are numerious things to look at before tearing an engine down. If you have little experience with engines, try another mechanic. I good mechanic can easily identify an electrical tick from a mechanical one as well as accurately locate the area from which the noise is coming from. At minimum, I would run a quart Mystery Oil, Rislone Engine Treatment or similar solvent in your engine for a few hundred miles before I simply handed it over to a mechanic to tear it down in order to "investigate" the problem. Put in something better than Mobil 0W40 when you change the oil.

Depending on the position of the car when you drain the oil, the amount that drain's out can be as high as 10 quarts. I usually have to refill with 10 full quarts in my 99.

Don't confuse "resistance to flow" as "less flow" :rolleyes:

How many miles on the clutch? Throwout bearing would make noise whenever the pedal is depressed. Is there any noise if you put the car in nuetral and let the pedal in and out?

Typically the throwout bearing will make noise when the clutch is disengaged. (pedal in), not when engaged. Are you sure it is coming from the transmission and not the engine?

Take it back and have them properly bleed the system. It may free thiings up.

I don't think they replaced the release lever ... I had not discovered this great site before having the clutch replaced, thus didn't know about that TSB. I notice that the TSB discusses the symptom as noise coming from the bell housing ... have people experienced clutch stiffness relating to the release lever issue? Thanks for the info. Porsche would NEVER label the TSB as a mechnical failure or they would have to replace all of them on their dime. When I had one of my Porsche clutches replaced, the Indy did not replace the lever, but when I had problems, he replaced it for free (except the $70 in parts) because he said he should have looked at the TSB's before he did the work in the first place.