C900 - oil showing significant concentration of metallic particles

Doubtful that it'd be rings, but it's unusual that you'd be seeing it at all. You could send the oil out to a shop to analyze it to find out for sure (different flavors of metal depending on what it is), or just tear it down & do it right. If you can get to the rings, you can get to the bearings, and the other way around...

Let us know what you find out though, please.

Dave Hinz

In more than a decade of tearing apart C900s, I have to say that I have NEVER seen metal in the oil while changing. I have seen metal shavings in the oil pan when doing an engine tear-down or rebuild, and occasionally collected on a magnetic drain plug, but never have I seen metal particles in the drain oil, dipstick, or filter.

You'd know pretty quickly if a ring had self-destructed. Better guess is rod bearings, or something (carbon? spark plug tip? something else?) gouging the cylinder walls. You can determine this with a simple compression test.

There is.

There are many places that do consumer-level oil analysis, I've used Blackstone in Indiana:

The breakdown of the analysis can give you a clue as to where the metal is coming from; then again, they're testing at minute levels, not at the visible. From their own site, the basic explanation is:

• Aluminum: Pistons, bearings, cases (heads & blocks).

• Chromium: Rings, a trace element in steel.

• Iron: Cylinders, rotating shafts, the valve train, and any steel part sharing the oil.

• Copper: Brass or bronze parts, copper bushings, bearings, oil coolers, also an additive in some gasoline engine oils.

• Lead: Bearings.

• Tin: Bearings, bronze parts, piston coatings.

• Molybdenum: Anti-wear additive, some types of rings.

• Nickel: Trace element in steel.

• Manganese: Trace element, additive in gasoline.

• Silver: Trace element.

• Titanium: Trace element.

• Potassium: Antifreeze inhibitor, additive in some oil types.

• Boron: Detergent/dispersant additive, antifreeze inhibitors.

• Silicon: Airborne dirt, sealers, gaskets, antifreeze inhibitors.

• Sodium: Antifreeze inhibitors, additive in some gasoline engine oils.

• Calcium: Detergent/dispersant additive.

• Magnesium: Detergent/dispersant additive.

• Phosphorus: Anti-wear additive.

• Zinc: Anti-wear additive.

• Barium: Detergent/dispersant additive.

Basically, what you're looking for is Aluminum or Copper (bearings) or steel (rings, cylinders, pistons, etc). If you have visible particles, you can easily test for this yourself with a magnet (in fact, this is why magnetic drain plugs exist, or some manuf. put magents in the oil pan baffles, is to catch the more common steel/iron bits from breaking in a new engine).

Start with a compression test, then a simple magnetic test on these particles. That should give you a pretty clear picture of what's going on inside your engine.

lycka till! GTr

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If you have a manual gearbox, are you sure it is not the manual gearbox oil you are looking at? You would see metal particles in the gearbox oil.

regards Charles

No it has a 3-speed auto transmission.

Thanks everyone for all the advice so far on this. I'm presuming that a compression test I need to take the car to a shop for? I'll get a sample of the oil and try a magnet on it in the next couple of weeks as well.

Craig.

-- Craig Ian Dewick ( snipped-for-privacy@lios.apana.org.au).

APANA Sydney Regional Co-ordinator. Operator of Jedi (an APANA Sydney POP). Always striving for a secure long-term future in an insecure short-term world Have you exported a crypto system today? Do your bit to undermine the NSA.

You can do it yourself. A compression tester should cost just under AUD$20, you'll need a torx bit to remove the plate over the spark plug well, and a spark plug socket or tool. To test compression, remove a spark plug, insert the compression tester (get a screw on with proper threaded adapter, and not the "push" type with rubber tips), disconnect the fuel pump relay and coil line, crank the engine, read compression.

Repeat.

Consider picking up at least a Haynes, or preferably Bentley, service manual.

Let us know what you find! Visible metal in the oil is highly unusual in an engine that continues to run.

lycka till! GTr

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Ok thanks for this. I'll hunt around for a compression tester. No doubt Ebay will reveal some for sale. That's how I'm sourcing most of the parts for my C900's btw... Much cheaper than trying to get them through local dealers who want an arm and a leg (and another arm!) for them. 8-)

I had no idea a compression test was that simple to do! You can tell I'm not a professional mechanic. lol

I have a Haynes manual which has already proven it's worth when I needed to replace the fuel gauge sender on my 1985 900i (some of the parts of the old sender are still in the bottom of the tank somewhere!). Trying to find a copy of the Bentley 8-valve Saab 900 book is something that's ongoing. Since it's out of print, they're very difficult to find new. I have a copy of the Bently 16-valve book which is good for some things relating to cars with the

8-valve engine.

That's exactly what I was thinking! I'm jacking up my 1985 900i as soon as I read this to check the brakes on the two front wheels. The person I bought the car from was truthful in saying that the brake pedal has to pressed all the way to the floor to get any effect. I have a spare master cylinder if it's needed, but I'm hoping it's something simple like a buggered seal in one the lines to the slave cylinders.

Once I solve that, I'll get a sample of the oil from the engine in the 1982

900S and do some tests on it based on everyone's advice so far...

Regards,

Craig.

-- Craig Ian Dewick ( snipped-for-privacy@lios.apana.org.au).

APANA Sydney Regional Co-ordinator. Operator of Jedi (an APANA Sydney POP). Always striving for a secure long-term future in an insecure short-term world Have you exported a crypto system today? Do your bit to undermine the NSA.

And a pretty good indicator of engine health, as well as a good diagnostic of problems.

As I always tell people: if you want to own a Classic Saab or Vintage SAAB, you have to have one of two things:

1) Money to regularly pay a mechanic or, 2) Mechanical skills to do the work yourself.

When people don't have money, and they want to keep the Saab, they learn the mechanical skills pretty quickly.

Classic Saabs are great cars until something goes wrong, then, wow, they are a fresh set of puzzles. How do I get that alternator out of there? The water pump is WHERE?!?!?! But, geez, replacing that clutch disc was easy...

lycka till! GTr

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