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Discussion Starter · #1 ·
So I have what I think is a timing chain related problem on my 2000 9-5 aero with 82k miles.

Over the past couple weeks, my car has developed this rattle that sounds almost like vibrating sheet metal on sheet metal. It comes in waves, getting louder then softer with a period of around 2 seconds when the car is idling.

This sound is intermittent and only happens right after startup usually going away after the car has warmed up and been driven for 10-15 minutes. Also, it doesn't happen after every startup, and after it goes away the chain is as quiet as it has ever been. Furthermore, you can barely here it inside the car with the blower off, I've had cars with exhaust and heatshield rattles that were louder. When the engine is running, the sound sounds like it is coming from the timing chain side of the engine under the timing cover.

So my question is what could this be?, and if it is the timing chain is it OK to swap to T5 cams on a stock ECU when I have the chain replaced.
 

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There are half a dozen threads on here right now about timing chains.

Have a read through this http://www.saabcentral.com/forums/showthread.php?t=112942

When a chain rattles through being worn it rattles all the time!

If its nosier particularly after start up its likely to be oil starvation, pointing to sludge potentially.
 

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Discussion Starter · #3 ·
The strange thing about sludge is that the car had the pan off back in january when the transmission was replaced, and supposedly it was sludge-free then.

I do need to do the PCV upgrade though, I'll just send it back to the shop to get the PCV job done along with getting the oilpan dropped and cleaned and the intake screen replaced.
 

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Maybe it needs a good oil change with a flush additive :confused:

82k is very early for a chain :confused:
 

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Discussion Starter · #5 ·
Oh I forgot to say I got the car at 69k miles, and I have been doing oilchanges with mobil1 0w-40 every 3k miles. It's been 600 miles since the last oilchange, and before the oilchange I drove the car for 100 miles with half a can of seafoam in the oil (never exceeding 2500 rpm and keeping the boost needle in the "white" part of the gauge at all times). My theory is that if it's sludge, the seafoam dislodged alot of old buildups and they're now clogging the catchcan, especially since this problem has popped up after the last oilchange.
 

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Your theory makes sense, I've never used the product so I cant comment, sorry ;oops:
 

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Discussion Starter · #7 ·
Chris 9-5 said:
Your theory makes sense, I've never used the product so I cant comment, sorry ;oops:
It's basically a hydrocarbon-based engine cleaner, it's used through the gas tank as a fuel injector cleaner, through the intake manifold as a valve and exhaust manifold cleaner, and in the oil to clean up buildups in the crankcase and oil passages. All I know is that occasionally you can end up with a clogged cat when you run it through the intake manifold because it's so effective at breaking up carbon deposits so I'm basing my theory off the crankcase equivilent of that.
 

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It might be interesting to drain the oil out through a piece of muslim cloth and see if there are lumps present :confused:

Its fresh oil so you can always put it back in ;)
 

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Discussion Starter · #9 ·
Chris 9-5 said:
It might be interesting to drain the oil out through a piece of muslim cloth and see if there are lumps present :confused:

Its fresh oil so you can always put it back in ;)
could I do the same thing with drops of hot oil off the dipstick?

I don't really have the time to get under the car right now
 

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My experience is that a worn timing chain makes the most noise from cold start until warmed up and mostly at low revs. The SAAB I4 engine has a chain guide fastened to inside of the valve cover. If the chain contacts this because it is loose and the tensioner is out of stroke, the noise is amplified by the cover. No amount of sludge removal, oil changes, snake oil or voodoo will quieten a worn chain. Change it. The beauty of a chain is that it (usually) gets noisy well before it breaks, unlike a timing belt.
 

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born again said:
My experience is that a worn timing chain makes the most noise from cold start until warmed up and mostly at low revs. The SAAB I4 engine has a chain guide fastened to inside of the valve cover. If the chain contacts this because it is loose and the tensioner is out of stroke, the noise is amplified by the cover. No amount of sludge removal, oil changes, snake oil or voodoo will quieten a worn chain. Change it. The beauty of a chain is that it (usually) gets noisy well before it breaks, unlike a timing belt.
But at 82XXX miles?
 

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Rattling noise on start up

I have a 2000 9-5 with the exact same symptoms, I first thought it was the turbo. It turns out the noise is coming from the middle muffler (resonator).
 

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woywitka said:
But at 82XXX miles?
my 95 20 lpt has a worn timing chain and it was like that at 78000 miles the trouble is its so expensive to change that it is cheaper to use it as it is then get another car when " or if " it snaps !!!!!!!!;oops:
 

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I have a similar issue with my 2.0 lpt. But as soon as it warms up any rattles go away & dont return until the car is started cold.

If it were me I would have changed the PCV pipes at the same time as doing the sump drop. If the insides of your PCV pipes are crumbling away, then thats just more gunk going into your cleaned sump & blocking the nice clean strainer.
My advice to anyone thinking of a sump clean would be to do the PCV upgrade first.
Just my opinion you understand. :D
 

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I hope it's not sludge

I may just be paranoid.

We recently bought my wife a 2002 9-5 Linear Wagon with 75k miles.

Right after I bought it I did the following:
-Changed serpentine belt & Idler pulley
-Did the PCV #6 update
-Changed thermostat and flushed the cooling system (changed with red antifreeze)
-Changed plugs
-Flushed transmission fluid
-Changed fuel filter
-Did the breaks & got new tires all around
-Changed oil & filter with Mobil 1 oil & filter

But I can't help being concerned with sort of loud engine noise I hear when listening to the engine from the outside. I can't tell what it is, you can't hear it from the cabine. It might be the timing chain, it sounds like some of the posters here describe.

I hope there is no sludge. After the oil change I ran the used motor oil through a cone paint filter and didn't see any debris. I will continue to change the oil as soon as I see the color change.

The car is getting about 22 MPG on the freeway. I think it is too low as it should be more like 28. Could all this be the sign of sludge?

Is it sludge?
Is the timing chain too stretched?
Can I tighten the timing chain without dropping the engine? Are there any tensioners that are exposed outside the engine?

My 900SE engine has a lot more room to work on, and from what I have seen is much easier to access the timing chain to tighten.

Any advice would be greatly appreciated. I just don't know what to expect if god forbid the chain snaps, or something else goes, or is, wrong.

thanks
 

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Boston-SAAB900 said:
I may just be paranoid.

We recently bought my wife a 2002 9-5 Linear Wagon with 75k miles.

Right after I bought it I did the following:
-Changed serpentine belt & Idler pulley
-Did the PCV #6 update
-Changed thermostat and flushed the cooling system (changed with red antifreeze)
-Changed plugs
-Flushed transmission fluid
-Changed fuel filter
-Did the breaks & got new tires all around
-Changed oil & filter with Mobil 1 oil & filter

But I can't help being concerned with sort of loud engine noise I hear when listening to the engine from the outside. I can't tell what it is, you can't hear it from the cabine. It might be the timing chain, it sounds like some of the posters here describe.

I hope there is no sludge. After the oil change I ran the used motor oil through a cone paint filter and didn't see any debris. I will continue to change the oil as soon as I see the color change.

The car is getting about 22 MPG on the freeway. I think it is too low as it should be more like 28. Could all this be the sign of sludge?

Is it sludge?
Is the timing chain too stretched?
Can I tighten the timing chain without dropping the engine? Are there any tensioners that are exposed outside the engine?

My 900SE engine has a lot more room to work on, and from what I have seen is much easier to access the timing chain to tighten.

Any advice would be greatly appreciated. I just don't know what to expect if god forbid the chain snaps, or something else goes, or is, wrong.

thanks
timing chain cannot be tensioned as it is done automaticlly by the chain tensioner, you can change the chain without removing the engine but only if the sprockets on the cam shafts are not worn and also the chain guides are ok ,if they are not it is a engine out job ,and in the uk this costs over a grand " £ 1,000 pounds" so on a older model it is not worth doing it unless you can do it yourself, the chain kit is about £250 !!!!!!!!:cry:
 

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There is a procedure to check the extension of the timing chain tensioner. It is a bit tricky to do, esp. without the detailed instructions from WIS or Alldata. The wear limit is 15mm and the end of tensioner stroke is 18mm. Your indie should be able to do this and evaluate the sprockets and guides with the valve cover off. If OK you can have a new chain rolled in for much less cost than pulling the engine for the full job. If you want to go DIY, there is the possibility to undo the engine mounts and shift the engine/transmission assembly enough to get the timing chain cover off.
 

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Boston-SAAB900 said:
I may just be paranoid.

We recently bought my wife a 2002 9-5 Linear Wagon with 75k miles.

Right after I bought it I did the following:
-Changed serpentine belt & Idler pulley
-Did the PCV #6 update
-Changed thermostat and flushed the cooling system (changed with red antifreeze)
-Changed plugs
-Flushed transmission fluid
-Changed fuel filter
-Did the breaks & got new tires all around
-Changed oil & filter with Mobil 1 oil & filter
Whats the purpose of changing the serpentine belt and idler pulley, please explain in detail.
 

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leon_ng said:
Whats the purpose of changing the serpentine belt and idler pulley, please explain in detail.

They are regular wear items that need to be replaced periodically.

Nothing at all to do with the title of this thread, just preventative maintenance that the poster decided to do for peace of mind.
 
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