Date: Thu, 02 Jun 2005 08:52:01 -0500 From: Dan <dannospamam.com> Subject: Re: warranty
On 6/2/2005 3:50 AM, Henrik B. wrote: > "Malcolm William Mason" <mwm1(spam)nospamedu> skrev i en meddelelse > news:ehet9190a0m0hjpl4tntkn2mmnong0pm7inospamcom... > >>This week I receive a letter from Saab USA stating that a small >>percentage of certain Saab engines could fail due to oil"sludge" >>accumulation. > > >>Does anyone have any insight to offer? > > > Hi Malcolm. > > The problem is, that on the newer Saab-engine (I4 with Trionic 7), the > pistons are smaller (and lighter). The piston rings are also smaller. This > all to reduce internal weight and resistance, to reduce fuelconsumption. > This means that during (cold)start, there's more gasoline running by the > pistons, down into the oil. This wears the oil a great deal, so that the oil > begins to build sludge. This sludge doesn't lubricate very well, and kan > cloack (spelling?) the oilfilter, oilpump and so on. > > Saab has tried for the last 5 years to solve this problem, by introducing > different types of oil-filtering-systems on the inlet-side, which obviously > isn't the right way to go. > > As the problem occurs due to the coldstart issue, the problem mainly effects > cars with at lot of coldstarts - short trips. On a longer drive, the > gasoline in the oil will have time evaporate. > > What you need to do, is change the oil (and filter) every 5.000 miles. And > keep and eye on the oilstick - to check for sludge. Use a good > fully-synthetic oil - 0W-30 or 0W-40. This will keep you a happy Saab-driver > for a long time. :o) > > Cheers! > > If SAAB has a confirmed problem, then why do they recommend a first oil change at 15K miles for 9-3? Also, what you describe being the problem I don't get. With modern machining tolerances should be tighter and less of a chance for gas to seep down the cylinder wall...
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