What does an oil analysis tell us

I've read through the IMS sticky. And I searched the forum to look for any information about what an oil analysis might tell us if we had an IMS about to fail. I found nothing. According to Bob is the Oil Guy's web site, here are the things that are revealed during a Used Oil Analysis: Al = aluminum Cr = chromium Cu = copper Fe = iron Pb = lead So my question is does a report on these items in a UOA tell us anything about our 996 engines and especially about an impending IMS failure?

An oil analysis is similar to a basic blood work up for humans. The data is especially useful when compared to previous readings. The Signum Oil Analysis, a Mobil-Exxon product now known as Mobil Serv Lubricant Analysis, shows data for 10 "Wear Elements", 5 "Contaminants" including coolant, and 5 "Additive" elements. The analysis shows most recent data AND trend data based on previous analysis. No, it can't specifically foretell an IMS failure, anymore than a blood test can foretell an organ failure. But "the pro's", meaning fleet operators, race teams, and military maintenance centers, rely on such analysis to plan oil change intervals, re-builds, and general mechanical mission readiness. Sounds good to me. relinuca

for most of us mortal po owners it is a waste [pun] of time. For the tinkerbells that believe that their po was built by and for the gods it is just another dna faulted trait of over thinking everything. all that is needed is po approved oil/filter changes at NORMAL intervals

I've had Blackstone do an analysis for me a couple of times. The numbers means nothing to me but they also give you a couple of paragraphs as to what is or isn't going on with your motor. For me it was just piece of mind before I had my IMS upgraded. Now that I've had it done I won't do another analysis for quite some time. In lieu of getting my IMS done I had changed to Joe Gibbs DT40 oil, added a magnetic drain plug, inspecting my filter after oil changes, changing oil every 6 months. The analysis was just one more safe guard for me while I was procrastinating getting my IMS upgraded.

Porsche951 - you sound exactly like me. My '03 C4 (owned for 14 months) now has 38k miles on it. The clutch seems very solid. I've been putting off having the IMS done until I also have a clutch done. Also frequent oil changes - inspection of the filter and a magnetic drain plug. I just can't seem to bring myself to have this work done with so few miles and what seems like a solid clutch. Probably short sighted.

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When I had mine done last month at 82k miles, I still left the clutch original since they said it was only 50% worn.

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The analysis results could provide you with an early warning of a pending IMSB failure, by say a high iron (or ferrous) PPM count, but the problem is if the bearing is bad enough to be shedding metal that gets pulverized to be fine enough to show up as parts per million in an oil sample the engine's probably just seconds away from grenading as the IMSB boom. High PPM readings on other metals or the presence of water or anti-freeze compounds can be a sign of metal to metal contact and wear or other trouble but the analysis only probably confirms what someone suspects based on the engine's behavior. Oil analysis is a mixed blessing tool. In some cases when one is dealing with a huge amount of oil analysis is a way to track the oil's condition to avoid replacing maybe 10s or 100s even 1000s of gallons of oil prematurely. In this case the cost/time involved in doing an analysis is more than offset by the savings that arises from *not* changing a huge volume of oil too soon. Also, of course one wants to avoid changing the oil too late, too. While even a 1000 gallons of lube/hydraulic oil is a lot of money you can be sure the system in which it is used represents magnitudes more money should it need to be replaced or repaired due to a break down in oil. As an aside, when I was talking to the guys at a truck stop oil change shop (and which had an oil analys system on site) and talking with the big rig drivers who were in to have the oil changed in their rigs, the word I got was some used oil analysis -- which cost at that time around $100 -- and some just changed the oil every month or so (every month or so on a big rig engine can be 20K to 30K miles...). For owners of private passenger vehicles -- no fleet managers included -- an oil analysis can be interesting to have done once or twice but as a regular thing? Not really. Where one might think an analysis might come in handy is with a new car, that one can do an analysis after so many miles to get a feel for the oil's life span. Even in this case there is trouble. One is -- this is my advice but one I follow -- is to do an early oil/filter service on a new car engine because a new engine sheds lots of metal and contaminates the heck out of its oil as it proceeds to advance thorough its break in phase (which can last thousand of miles based on field and lab testing). Thus an oil analysis of the initial fill oil would likely find elevated levels of all wear metals to the point you might think the engine's on its last legs. Even the 2nd fill of oil would very likely show elevated levels of metal after maybe just 1000 or so miles. (After changing my 2008 Cayman S's oil at around 750 miles and then again at not even 1500 miles upon examining the oil filter housing oil in a clean drain pan I could see faint signs of glitter -- aluminum -- in the oil. The engine was still shedding loads of metal.) So one would need miles on the engine to the point it stops shedding metal to provide a more realisitic oil analysis result. The trouble is what is one going to do in the mean time? Just run the oil? Well, my advice would of course not just run the oil. My advice would be to after the initial and premature oil/filter service -- unless forbidden in the owners manual -- then at least change the oil again at the end of "break in" and then on 5K mile intervals from then on. Say one changes the oil at 1K miles, then again at 2K -- end of "break in". Then the next oil change would be at 5K miles -- just 3K miles after the 2nd oil change -- and then again at 10K, 15K and so on. If at some point one wanted to run the oil longer than say 5K miles an oil analsys might provide some idea of whether one's usage and the oil and the engine were up to a longer change interval. The trouble is one would need to establish some history so periodic analysis would be needed to get a feel for the oil's rate of degradation. Given the time and cost of doing an analysis: the preferred method is to remove the oil filter housing and take a middle sample of this oil for analysis. Send it out then if it comes back "ok" to install a new filter element and the necessary o-rings and fill the filter housing with fresh oil and install until the next time; this represents a considerable expense. And the car is laid up while one awaits the results of the oil analysis. (When I lived in mid-MO I had a big rig truck stop just two miles away that I could run an oil sample out to and have analyzed while I waited. But I didn't have to run a sample out to the facility. I could and did just drive my car into a bay, a big rig bay which from inside the Boxster was like straddling the Grand Canyon, and the tech managed to pull a sample of oil out via a small tube fed down the Boxster's dipstick tube. The cost then -- circa 2002 -- was around $25. This represented a good portion of the cost of just changing the oil.) I've got better things to do with my time and my cars so I just pick an oil change interval that based on my experience has the oil replaced while a bit prematurely not that much. As I have often stated I would much rather toss away some oil with some life left than have to toss away an engine with no life left because I tried run the oil too many miles too many times. And I leave the oil analysis to those that have huge amounts of oll to worry about.