Noisy chain / knocking

[carrera]

This should be perhaps subtitled the "Oops I did it again" thread, as in oops I have taken on another possible rescue project.

I picked up another 9-5 yesterday. It's a 2003 Glacier Blue Vector 2.0t, so not an Aero. Mechanical issues this time, I can either repair this one or use some parts to donate to the Graphite Green Aero. Not much in the way of service history, but the engine bay is generally clean, has fresh coolant and oil level was almost on max. It's done 133,000, the timing cover is not clean with a long standing build up of oil,some fresh.

The engine is noisy, rattle from the timing chain area, and a knocking which seems too light for big end knock but may not be. I thought the knock was also coming from the chain area, but it seems to get louder around cylinders 2/3 in the sump area. Idle is fine, it gets more pronounced above 1500 rpm. No oil warning light issues.

I have been told that the engine still performs fine, so I am a little sceptical that there is a rod issue as I would have expected something more catastrophic to have happened already

I have spent a couple of hours reading around, my plan of action is as follows:

1. Remove the chain tensioner and measure how far it is projecting - that'll tell me how bad the wear on the chains / guides is
2. Drop the sump, check the strainer first, then remove/replace the rod caps one by one to inspect the bearings and crank. I don't have plastigauge, will I be able to get a micrometer in to measure in situ ?

I haven't seen anything saying that the rod bolts are stretch / TTY, are they reusable ?

Any other B205/B235 likely issues I should be looking at ?

Better go change my signature

[phoenix]

WIS doesn't make any mention of needing to renew the rod bolts- they're actually studs with nuts (like the exhaust manifold)

[carrera]

Thanks for that, that was my deduction, at least that means I can inspect without incurring cost, so many other manufacturers had moved to TTY by this time

Any other thoughts on my diagnostic route ?

[fka]

If you take the valve cover off, you might be able to see if the top chain guide is intact (I'm sure I remember someone with a worn chain plus broken guide that made and odd rattle + clunk sound ..) and check wear on the sprockets

[Audax]

From your description I would think that the bottom end has gone. I knew of one chap who had a 9-5 which had a similar problem and he had only got about £1000 to either repair or replace the car but could save a few hundred quid a month. He asked what would happen if he kept driving it and we said eventually it'd die but we didn't know how long. He drove it for 5 or 6 months after that with the bottom end knock getting progressively worse until he could afford a decent replacement!

[carrera]

Cheers both, that's helpful.

I'm surprised that the bottom end could survive that long when it was knocking. To be honest, I'm hoping that's the issue, sump off, a good clean and new bearings would seem to be an easy & fairly cheap fix. I'm a bit more intimidated by doing the chains, given the problems with limited access, especially as I haven't yet got my head around why the new chain needs to be rolled on.

Anyway, here's a photo. Somewhat strangely, I quite like the colour

[sgould]

I've always liked that colour, it only lasted for 2 years.  We nearly bought a 9-3 in Glacier Blue, but got the Merlot one instead.

[carrera]

I dropped the sump off this afternoon. All the nuts came off without any difficulty, which made me think they had been off before.

I drained the oil and though there was not much in the way of shimmer, I found some small particles of metal in the bottom of the drain container.

Numbers 1 & 4 big ends were whipped off first. They looked a little worn, with some signs of micro material removal. Nice of Saab to number the rod in the factory

Then the crank was turned 180 degrees and numbers 2 & 3 were removed

Hmm, that's not right, looks like the bearing has rotated on number 3 and the locating tab has been destroyed allowing lateral movement - this is just as the bearing cap came off.



A better close up



Now let's remove the bearing and look at the journal, how bad is it ?



Doesn't look great does it, but surprisingly after measuring with the micrometer it is still well within wear limit.

...... and now the final reveal



Time to get my thinking cap on

I could clean the journal up "in situ" and provided it cleans up OK and is still in spec put a new set of bearings in (I have "hand repaired" a crank successfully in the past)
Drop the engine out, remove the crank and take it for a polish or regrind
Drop the engine and put a s/h crank in
View the engine as being scrap, take the bits off I need and break the car

Before I finalise my decision I suppose I should do the measurement of the timing chain adjuster

Any other thoughts / suggestions -  from what I have read the bottom ends of the B2x5 engine are supposed to be pretty strong, though perhaps not as good as the B2x4 engines ?? 

[Audax]

Any other thoughts / suggestions -  from what I have read the bottom ends of the B2x5 engine are supposed to be pretty strong, though perhaps not as good as the B2x4 engines ??

Love the colour of that car too, always wanted one but never likely to own one now.

I'd say that the B2x5 engines are plenty strong, I would suggest as strong as the B2x4 just the oil sludge problems gave them a bad reputation. I would seriously take a look at the chains at this point but as you say the timing cover has oil on it then at this point the only way you're going to get the engine good is to drop the entire lump out and rebuild the bottom end, put on new chains, probably want a new head gasket and oil pump seal to get the timing cover sealed up again... once you get into that territory you're looking at overhauling the entire the engine and personally I wouldn't bother to do that. Unless you want to do this for fun and have access to a decent workshop you can leave it all in bits while you do the work it's looking like it's not worth the effort.

[carrera]

I have found the source of the oil coating.... the connector for the breather box was off, so that's good news I think - unless it has been a deliberate removal to reduce crankcase pressure in some way. I doubt that the alternator will ever suffer from corrosion. 

I do do some car repairs for fun, and because of that am fortunate that I do have access to a decent, dry workshop with a ramp. It makes life much easier, but it gets cold at this time of year as there's no heating. brrr

Having taken the sump off for the first time I know how easy that is, and it's great news that mains and big end bearings can be changed in situ. It'll be a bit of a pain (meaning more work) taking the engine out, but I can see it will make doing the chains easier simply because I will be able to see what I am doing.

Do you have to take the head off to replace the timing chains ? It seems you don't if you are rolling the chain on, but do you if simply fitting new ones?

Since posting the update above I removed the strainer from the sump. Nice design by Saab I thought, deep reservoir avoiding the need for the usual baffles. Anyway, the strainer was not massively clogged, but there was more fine bearing material around the outer edges, maybe a 10mm or so band round the edge. It would certainly reduce flow, but I would see that as the consequence of the bearing failing rather than the cause. Likely cause simply low oil ?? I left it draining overnight so might put a picture up later.

Next step is to remove the tensioner, but I will need to check that I have a 27mm socket first. I'm pretty sure I have one,, even if it's 3/4 drive.

Thanks for all the help and advice, it's really appreciated as I'm a bit short on Saab specific engine knowledge.

........and it seems everybody likes a Glacier Blue 9-5     

 

[Audax]

Do you have to take the head off to replace the timing chains ? It seems you don't if you are rolling the chain on, but do you if simply fitting new ones?

You don't have to take the head off but the corner of the head gasket can get mashed when removing the timing cover. I wouldn't bother rolling a new chain in as every 9-5 that has needed new chains (based on tensioner wear or noise) that I've seen also needed new guides and rollers and a balance shaft chain. Given what you've said about the bottom end and the chains it'd be far more straight forward to do a complete strip down and rebuild on a bench if you're so inclined, check oil pump tolerances etc. at that point I'd be going for a new head gasket too just simply due to how much work it is the extra time and cost will be negligible overall.

[carrera]

I extracted the chain tensioner this morning. Lots of faffing around working out how to get access and where the allen key goes to fix the tensioner in a locked position, but now I have done the job I know it's not difficult at all.

Chains need doing I think, about 18mm of extension. Just for fun I included the strainer in the photo as well. The sump has lots of copper bits in it. That seems quite a lot of wear for 133,000 miles ?

Looks like engine out now. As you suggest, better for doing the chains, and for me to check / repair the crank.

When I have done clutch changes on the drive on a 9000 I have always dropped the engine out from below. I now have an engine hoist and have seen a photo with just the engine removed from the top. I assume that's the best way from this point ?

[Audax]

Drop it out from below if you can, only reason I can think of to take it out the top is if you didn't have a tall enough lift.

[carrera]

Right, slight change of tack, the engine isn't quite out yet, and oops I did it again, I did it again.

I'm picking up another 9-5 tomorrow.    It has a good engine (don't they all)  which I can use for this car, and then use other components to do the graphite green car which will leave me with a supply of spares, some stuff for ebay or sale on here, and a shell. I think it makes sense.

The car I am picking up is an auto. I have assumed the big metal bits on the engine are the same, but there may be some detail differences between the auto and manual on the peripherals side so expect to have to swap the engine looms over, maybe alternator,???

Have I been wise or foolish, any words of wisdom for the transplant 

[sgould]

I think that the looms for the engine all go through the big connector on the bulkhead.  Maybe one or two from the ECU bypass that connector.

Most of the bits seem to be the same, but the "engine" mountings on the gearbox side are different.

I've seen someone struggle with the flywheel/torque convertor end.  I can't remember which way around, but the end of the crankshaft on one engine has a central spindle. The spindle is a lump of metal and can be "persuaded" out.  It's not part of the crankshaft.

The actual electrical bits and wiring are beyond my experience, but the instrument panels and SID are different.  The SID difference is usually just programming.  The instrument panel is physically different.  The auto version has the gear selection displayed on it.