98 S70 Non-Turbo Automatic Tranny 172K Miles

I have recently developed a mysterious oil leak that I am having a difficult time locating the source. I have read many posts referring to the rear main seal and that this is an extremely expensive fix if it is leaking.

Where is this located? Is this what VADIS refers to as the "Crankshaft seal, rear"? If so, it calls for removing the gearbox - is this done with the engine in or out of the car? (probably showing my ignorance here, never done engine or transmission work - but hey - no such thing as a stupid question, right?)

Where is this type leak most frequently in evidence?

Thanks, Calvin

Thanks guys for the information/tips.

So far, I can't find an active drip, but there is oil on the underside of the "rear" of the engine.

There are 10-12 golf ball size or smaller spots on the driveway but by the time I see them, they are fairly "dry".

Couple of questions.....

I know I have an oil trap but thought the 98 didn't have a PCV valve. Is that correct?

If it is the RMS and I clean or replace the oil trap and hoses, might the leak stop or at least not get any worse?

Appreciate your input.

Thanks, Calvin

Replacing the oil separator and its associated lines will always help. Some have reported all leaks stopped, others have reported less oil leaking. The internal pressure in the crankcase needs to be relieved before it blows the RMS and cam seals completely out.
Volvo isn't the only car maker with this problem. My wife's 2001 A4 had a sudden blowout of a rear cam seal in her car when it was -15F. There was a small fire in the engine bay when she puled into the garage and a trail of oil all of the way up the driveway and into the garage. Her car had 55K miles on it and it always used synthetic oil.

Klaus

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I still miss my 164 and my 854T. Just driving a V70R :)

Klaus, tell me about it!

I have a 1999 Saab 9-5 and these cars are on their SIXTH redesigned PCV configuration.

This is surely one of the costs of the improved engine efficiency of "modern" automobiles. About the time they get it right, we'll probably abandon it all for electric or fuel cell or something.

By the way, Audi, Volvo, Saab......all European. Come to think of it, with a six cylinder and about the same MPG, my wife's 2000 Odyssey has never had a PCV complaint or leaked a drop of oil at 150K plus. What's that all about? Not that it isn't a boring drive!

Regards,

Calvin

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I still miss my 850 Turbo....

(sold it when I got the Saab and regretted it ever since!)

Hi,

just have a look at your power steering fluid as well.
my 850 /94 started leaking at the upper pinion gasket ie. where the steering wheel axel comes to the power steering rack. Resulting into small spots of oil on the ground and very dirty bottom of the car on driver side as the engine cooling blower blowed all the leaking oil backwards.

br Tapsa

The rear main sel is between the engine and the transmission. There is a hole built for that purpose, to let the oil out should it leak. So the oil drips should be on the ground under the steering column.

To replace the RMS, the transmission needs to be removed - read expensive - and the $40 seal is replaced.

Typical cause of this is crankcase overpressure due to a clogged PCV line or oil seperator box. At idle, if you loosen the oil fill cap without lifting it up and it "dances", you need to fix/replace the PCV system. If it gets worse, your engine will blow out the exhaust cam seals also.

Klaus
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I still miss my 164 and my 854T. Just driving a V70R :)

Is this what VADIS refers to as the "Crankshaft seal, rear"?

Yes. You know which side of the engine is the rear, correct? The tranny is on the driver's side, so there you go.

I'm pretty sure the leak is where you would expect - the joint between the engine and tranny. My guess is you pull both together, but the experts can address this.

Good luck. I once thought I had an RMS leak, and the first contradiction was my leak was in the wrong place.

Don