I'm just going on my almost 10 year experience with my Turbo.

On a mechanical level though, as Kevin points out, there is really no way any variance of oil level between (from max to min on the display) could affect the quantity and pressure of the oil delivered to the engine.

 

i would ordinarliy defer to your expertise, and am only passing along my anecdotal evidence, based upon my experience. i couldn't speak to any possible difference in oil pressure by being a quart low or not. we've been talking about "sound/noise" and what may or may not lessen it perceptually, as opposed to any pressure differential. i can't imagine there could be less "pressure" as you point out, provided one is within recommended oil quantity limits.

i'm not at all sure to what i should attribute my perception of "less" "ims" rattle being noticably present when i have the oil topped off as opposed to being somewhat "low". i'm just not willing to attribute it to my imagination, whatever the cause.

 

Mine does not change in sound with oil level - only with time between intervals. When I first get the oil changed, it is really quiet. It slowly gets more noticeable as the oil ages.

 

You will know when the IMS noise becomes a problem. I purchased my car new in '02 and had the typical annoying IMS noise for 8 years. It was on and off, some days it was loud like many other 996TT's I have heard and some days you could barely hear it. One day last year at 105,000 miles, it got much louder. I drove it for a couple of days, then decided to bring it in for a second opinion, as it was just too loud. It was more like someone was inside the motor, hitting the case with a hammer pretty hard. It did go away at higher RPM's or I could not hear it over engine, exhaust and road noise. Having been through this, I think you will know something is wrong when/if it fails. This is a very weak point of these engines and I think we will see more of this type of failure as the mileage of the average car increases. My car has much higher than normal mileage and has been modded since 3 months after I purchased it, so it has had a long life at almost twice the OEM torque figure. I feel the additional power, over 100,000 miles of use contributed to the IMS failure. In my case, the two woodruf keys that hold the gear on the IMS wore and became rounded causing additional play. Everything else was perfectly fine, including the IMS bearings. In fact, my tech was shocked at how minimal the wear on the motor was - he inspectied every part, checked the rods, etc. and everything was factory spec...Of course, we changes all the bearings in the motor, but we really didn't have to, as there was no real wear on them...Anyhow, what I am saying is I think you will know something is very wrong if your IMS fails.

 

that's very helpful info. it doesn't surprise me to hear of a possibly causal relationship btw higher mileage and mods either re the "noise". my lower mileage "02 stock x50 car didn't have it until 50k+ miles. but the modded car i now have has it ( but it purrs if i follow my oil topping off protocols.. call me crazy ). so who among us truly knows.

it doesn't bother me beyond being a curious peculiarity. again, thanks for the story. i would hope to avoid all that one day, and i've got about 78k on the clock. not gonna worry about it

 

It's one of those things that you can not predict. I have heard of several non-modded cars with only about 20K miles having had the same failure I experienced, so you just never know. I hope I get at least another 105K miles on this one. Overall it's rare, but when you see the design of the shaft and sprocket, it becomes apparent that it's not a bulletproof design. I think with extended use, especially at higher HP and torque levels, it is likely to eventually wear and cause problems. When I think of how many times those two little keys were exposed to 700 ft/lbs. of torque over a period of several years, I am not surprized they wore a little.

 

BTW John - OT and all - still loving the sound of my 3" X-cellerator. Just awesome and never tiresome. Went for two major drives around lake tahoe and just loved the sound on all the different aspects of the road. The rattle is still there, but once on throttle the sound is intoxicating!

 

Hi Nikolas,

Nice to hear from you, it won't be long until ski season again!

It goes without saying that I know the intoxicating sound you are referring to... I love it, too! It's a beautiful sounding system that you will not grow tired of...very unique among the aftermarket 996TT exhausts that I have tested or used...

BTW - I'm not sure of the rattle you mentioned, but that's not normal for these systems. Please email me a video or recording of the sound, so I can hear it. If something is wrong, we can explore correcting it for you.

 

Mark- love the avitar pic!

Here's my $0.02 (think it's been said)- cut open your oil filter at your next oil change (I go 3k miles personally)- if there's no metal in it, you should be fine.

In my experience, using a different oil (not turning this into a oil debate) will significantly quiet the noise. In my opinion, less noise = less wear.

PM or email me, I'll tell you which oil to buy, and where to get it near us.

Paul

 

thanks paul! will do. since SG who does all the wrenching on the car and uses m1 0/40 exclusively..i'd have to switch and bring oil! do you top off? or wait until you need a qt?? when it comes to oil choices, you know your zddp!..and you certainly have excellent taste in neighborhoods!

see ya on the street with those gt2 wheels you got!

 

I keep mine at the full level, maybe one down.

 

i would have thought so.. cheers.

 

Thanks John - the rattle is the one we are discussing in this thread - IMS, not your exhaust. No rattles from that thing, just music!

 

:-) That makes more sense...I was wondering...

BTW, we recently shipped another one to your area...

 

The guy in Reno?