If you ever shopped for a new 986, 996, 987 or 997, you couldn\u2019t help but notice that
\nthose cars were expensive. You have probably also noticed that a used, clean early
\n986 can be bought for really nice 914 money, and an early, clean, 996 can be bought
\nfor nice 911 SC money. On the surface that doesn\u2019t seem right. Is this because of the
\nway they look, or something deeper?<\/p>\n
Let\u2019s examine some problems these cars can have, with a clarification that those
\nproblems might happen sooner, or later, in a car\u2019s life. To illustrate, a 1973.5 911T
\nwith CIS fuel injection will probably require valve guide replacement between 110K and
\n125K miles. An \u201987 Carrera will probably need clutch work between 60K and 75K
\nmiles. Unlike the predictability of those repairs, an early 986\/996 can have a leak
\ndevelop at the crankshaft seal, let\u2019s call that seal the RMS (Rear Main Seal) behind the
\nflywheel, but the leak might not occur until after you\u2019ve bought a low-mileage garage
\nqueen, and actually start using it.<\/p>\n
![\"Watercooled](\"http:\/\/staging.redlineservice.net\/wp-content\/uploads\/2013\/05\/MarcWaterCooled.gif\")
\nThe RMS and related parts can have a host of potential problems. Very early 986\/996
\nengines were constructed using a bearing carrier that supported the crankshaft and its
\nbearings. That carrier, in some engines, can move out of position, which will cause the
\ncrankshaft to be off-center inside the engine crankcase. The result is that the
\ncrankshaft will also be off-center inside the RMS, and oil will leak past the seal.<\/p>\n
Porsche offered for sale a device that has a precision fit for the crank to case interface,
\nand is used with the seal removed. If the tool does not fit, the technician reads in the
\nPorsche manual, \u201cthe motor must be replaced.\u201d Uh, oh. Can you imagine buying a
\ntop-dollar, show-winning, 996 with only 10K miles on its odometer? And six months
\nlater you have to spend $15,000 to replace its engine
\nAs close as one outside the Porsche system can determine, an RMS\/carrier failure
\nusually occurred in the first 15-20K miles, some as early as 8K miles, and many of
\nthose engines were replaced under warranty.<\/p>\n
In addition to the above, the RMS can also leak from normal wear and tear, or after
\nreplacement by an installer with inadequate skills or an incomplete tool set. Porsche
\nhas had three different installation tools, along with a number of seal updates. If the
\nlatest generation tools and seal are used, an RMS repair can usually be done with longlife
\nsuccess.<\/p>\n
Speaking of the RMS problem, you think that you might have one, because of oil
\ndripping at the engine to transmission mating point. You remove the transmission and
\nflywheel to do the repair. It turns out that the RMS is dry, but a few inches below the
\ncrankshaft is a cover, and it\u2019s soaked with oil. That cover is usually called the IMS
\n(Intermediate Shaft) bearing cover. It is secured using three bolts. Those bolts screw
\ninto threaded holes, and according to Porsche, should be replaced with bolts that are
\nmicro-encapsulated with sealing material. When the repair is done it is also
\nrecommended the five, visible case half bolts be replaced. Replacement bolts will also
\nbe made with sealing material on the threads, and on the sealing surface of each bolt
\nhead flange.<\/p>\n
![\"Water](\"http:\/\/staging.redlineservice.net\/wp-content\/uploads\/2013\/05\/watercooled.jpg\")
\nOK, the IMS bearing cover has been mentioned, but what about the IMS bearing? Well,
\nwhere does one start regarding the IMS bearing, other than to speculate about poor, or
\nunder-engineered design. Porsche started the bearing fiasco by using a double row
\nbearing, then switched to a single row design, followed by a larger single row
\nbearing, ending with a complete re-design in 2009, when the IMS bearing was
\neliminated. It would be fun to compare the IMS bearing issue to the long-ago, 944
\nengine mount fiasco, but when difficulty of repair, and costs, are considered, it\u2019s no
\nlonger funny.<\/p>\n
Can a failed IMS bearing be fixed? Kinda. There is even a \u201cfix\u201d that might be
\nconsidered better than what Porsche is currently offering. An engineering firm in
\nIllinois has re-invented the wheel, er, bearing, and has made an upgrade kit to fix the
\nIMS issue. Their kit includes a ceramic bearing, which seems to have a longer duty
\ncycle that any of the Porsche bearing versions. The engineering firm, with the help of
\ndurability tests, has determined that reliable life of a stock bearing is about 40K miles,
\nwhile a ceramic replacement should last 60K+ miles.<\/p>\n
Along with regular oil changes, Red Line Porsche Service, in Los Angeles, CA,
\nrecommends a thorough inspection of the oil filter at each oil change. If any metal
\ndebris is found in the filter, chances are good that its origin is the IMS bearing.<\/p>\n","protected":false},"excerpt":{"rendered":"
If you ever shopped for a new 986, 996, 987 or 997, you couldn\u2019t help but notice that those cars were expensive. You have probably also noticed that a used, clean early 986 can be bought for really nice 914 money, and an early, clean, 996 can be bought for nice 911 SC money. On […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[6,7,8],"tags":[11,13,25,26,27,10,28,15,19,17,23,18,22,20,16,29,24],"_links":{"self":[{"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=\/wp\/v2\/posts\/90"}],"collection":[{"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=90"}],"version-history":[{"count":11,"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=\/wp\/v2\/posts\/90\/revisions"}],"predecessor-version":[{"id":126,"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=\/wp\/v2\/posts\/90\/revisions\/126"}],"wp:attachment":[{"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=90"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=90"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.redlineservice.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=90"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}