Date: Fri, 13 Dec 2002 04:58:59 GMT From: "Morgan Bullard" <mjbullardnopsampammersdie.earthlink.net> Subject: Re: Saab 900 2.1 oil leak at front of car
"tom reingold" <tlr244nopsamnline.net> wrote in message news:3DF7C40C.2090208nopsamnline.net... > > > Homer wrote: > > It's a 900 Cab, and the oil leak is at the front of the car and from where > > that bulbous bulge joins the motor. It looks as if it's a rear main seal, > > but with a Saab everything is arse about, and it's an Auto so I'm confused. > > Assuming it is a RM seal is this a tricky job for someone with a small brain > > to do at home? Is it possible to press a new seal successfully in without > > pulling the whole motor substantially apart? Thanks. 5000km of ownership. > > Headgasket, roof hydraulic strut $12000 crash and rear main seal. Ya gotta > > love these Swedish monstrosities doncha. > > > > > > I don't know how hard it is to do, but my mechanic charged me about $350 > to do. That implies to me that he didn't have to pull the engine to do it. > > I believe -- but will never be able to confirm -- that the cause of the > leak was switching to synthetic oil when the car was old. My mechanic > says he swears off that stuff, perhaps for this reason. Synthetic is usually easier on oil seals than mineral oil, (diester oil not included!), but most synthetics have few VI enhacers and Mobil 1 has _very_ good/strong detergents. The result is, compared to minerals oils, different "rubbers"* used in seal will tend to swell less. On a new seal that is still soft and flexible, this isn't a problem, on an old hardend seal leakage can often result. This is more true with the older seal designs that used, NBR, ACM, and silicone elastomers. The newer seal designs often use FKM, which doesn't swell as much, but gets brittle at low temps and is expensive. Synthetic oils are also less likely to carbonize under the seal lip. Carbonization can cause leakage, but isn't a common failure mode. But in an engine with newer seals, synthetic oils should work just fine, on older engines, use what every you have been using, assuming it meets the required API or ACEA specs. * "rubber" = Nitrile(NBR) , Hydrogenated nitrile (HNBR), Polyacrylic (ACM), Silicone (VMQ), Fluoroelastomer (FKM, often refered to as Viton(tm DuPont)) etc. > > This was a 1986 900turbo. I think I had the work done in around 1995. > I don't have that car any more, and I miss it. But to be honest, it did > give me a lot of trouble. > > -- > Tom Reingold > Noo Joizy > >
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