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Discussion Starter · #1 ·
A friend is looking at buying a 2002 900SE 2.0L Turbo Convertible. An odd ticking sound has him thinking it's a valve issue. I'm thinking it may be a lifter as the sound fades away as the engine gets warmer. Anyway, I'm going to do a compression test to at least rule out a leaky valve. So, I need to know which fuses to pull, etc.

As I recall, the procedure runs like this:
On a warm engine and with the engine running, pull fuse #___ to the fuel pump and then the engine will stall.
Pull fuse #____ to the ignition.
Disconnect wiring harness from the DIC.
Remove the DIC.
Remove all 4 plugs.
Screw in compression tester to each plug hole and crank 10 times.

Did I miss anything? Anyway, I need to know which fuses to pull.

Thanks.
 

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Fuse 32 is the fuel pump
Fuse 17 is listed as : main instrument, SID, Trionic(Turbo), auto trans.
When doing a compression test there shouldn't be any obstruction to air flow, throttle valve should be held wide open.
I don't think a leaky valve would tick. Sounds more like a valve lifter Problem?? I'd want to make sure there is good oil pressure
 

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Discussion Starter · #3 ·
He is seriously considering buying this Saab fully in the knowledge that the B205 has been known for it's sludge problems. I've told him that #1 on the fix-it-when-he-gets-it-home list is to drop the oil pan. I think it's a lifter problem too, but he wants to be sure.
 

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Discussion Starter · #5 ·
It's done

185-185-185-185. Still would like to learn how to check oil pressure. What sounds like a ticking lifter and an intermittently rattly turbo, and given that it's a 205 engine, I'm betting it's oil-starved. If he buys this car, I'm going to suggest we drop the oil pan, clean the screen, and refill with synthetic. Then, we'll button her back up and see if that doesn't take care of the rattles and ticks.
 

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There are kits on the market for this oil pressure testing. A sandwitch plate deal at the oil filter has been discussed here.
But, as far as I am concerned, if the oil lite ever glows - its o'er and time for a "new car".
 

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The firsy thing that I would do is turn on the ignition (witout starting the engine) and make sure that the oil light on the instrument cluster lights. At least that will tell you if the oil pressure circuit is connected. Just remember that if the oil pressore sensor in the back of the engine brings in alarm, the oil pressure is down to around 5 lbs, which is way to low. Also, be aware that oil pressure is waht pumps up the hydraylic lifters; if the oil pressure is already low, the lifters will start to chatter. BTW, there is no quick way to check the oil pressure, like EW said, the sandwich is the easiest way. But you have to remove the oil filter (probably change the oil too), connect the sandwich adapter, put on the oil filter, find a suitable battery & ground, run the wires into the cabin, mount the guage, connect the guage, start the enginge, test the oil pressure. If the pressure is already low, the engine may need bearings and maybe even a crank... Ron
 

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I would also check for an exhaust leak. These sound just like ticking lifters/valves and usually fade away once the engine warms up and the metal expands. However, knowing that this is a 2002 T7, I would run from it if it's in the valve train. He doesn't want to buy a sludge monster.
 

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Discussion Starter · #9 ·
I would also check for an exhaust leak. These sound just like ticking lifters/valves and usually fade away once the engine warms up and the metal expands. However, knowing that this is a 2002 T7, I would run from it if it's in the valve train. He doesn't want to buy a sludge monster.
Hey Frank,
I have forwarded your input to my friend. I am familiar enough with this forum to know about the sludge issues and have also passed along my concerns to him. I would ask you however, how can I go about determining whether or not this could have a leaky exhaust valve. I did do a compression test thinking that would tell me. 185-185-185-185. Would this not show up a leaky valve? Engine was run for about 5 minutes at the time of the test, so just barely warm. And did it dry...not wet. Suggestions?
 

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Hey Frank,
I have forwarded your input to my friend. I am familiar enough with this forum to know about the sludge issues and have also passed along my concerns to him. I would ask you however, how can I go about determining whether or not this could have a leaky exhaust valve. I did do a compression test thinking that would tell me. 185-185-185-185. Would this not show up a leaky valve? Engine was run for about 5 minutes at the time of the test, so just barely warm. And did it dry...not wet. Suggestions?
I was referring to a leaky exhaust manifold or flange. I found a crack in one of the flanges on my exhaust at the turbo. It sounded just like a valve with a constant tick-tick-tick that would change with engine RPMS. All you can do it check for tightness on all of the bolts and listen for it.
 

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Discussion Starter · #13 ·
Seems like we're in agreement

John, thanks for the confirmation. I agree that these compression readings show good valves.

Frank, I always value your input. Since we seem to be in agreement that the valves appear to be in good shape at first blush, he's pretty comfortable buying this car. We'll be dropping the oil pan on Thursday afternoon (he has strict orders from me to baby this car until then). When the pan comes down, we will be looking very closely at the exhaust side of the turbo when the downpipe comes off. I'll report back here what we find.
 

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While the pan is off, don't forget to check the rods for looseness. It's kind of hard to check the mains without pulling one cap at a time and using Plastiguage to check the clearance... Ron
 

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Before you buy it see if you can pull the valve cover and check for sludge in the head. Also, you could drain the oil through a gold permanent coffee filter ($5) to look for signs of sludge in the oil that comes out. I always drain my oil through one and when my 2001 showed "coffee granules" in the filter I dropped the pan. Good luck with it. Don't forget to pull the oil pressure regulator and give it a good cleaning.
 

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Wouldn't you need a leak down tester to test for valves that don't seal properly (i.e. bent or burnt)?

Like this thing: http://en.wikipedia.org/wiki/Leak-down_tester

Seems like a long time ago I read an article that described different behaviors of the needle of a compression checker to give you clues on valves as the needle ramped up (or not in the case of major failure). I would trust the leak down tester to at least find out if all the valves on a given cylinder seal properly.

I don't think a compression checker will tell you the full story.
 

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Discussion Starter · #17 ·
Don't forget to pull the oil pressure regulator and give it a good cleaning.
It's been 2 years since I dropped my oil pan. Remind me where the oil press reg is?
 

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Discussion Starter · #19 ·
While the pan is off, don't forget to check the rods for looseness.
That's a great suggestion. What does "too loose" feel like? Just grab onto each rod and give a good shake?
 

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Right, there shouldn't be much play. If you can hear it move, that's too much. Look for a post from Nicole a few weeks ago. Her bill was $1500 or so to drop the pan and get the main bearings changed without pulling the engine.

ANd you might talk your friend into cutting the balance shaft chain and pulling it out. That's one less thing to break... Ron
 
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