H engine in 9-5?

I think you have lost your head so here is some help to see if you can get it back on its stand (neck).

He is honest. He probably knows the problem but wants an easy(ish) life and no customers coming back to complain.

Missing the meaning of WTF.

Crankcase pressure can happen in one way (and with imagination in two more ways).

Method 1. Gases escape from the piston rings/cylinders into the cranckcase etc. Worn/broken rings or worn cylinders.

Method 2. Gases escape via the valve guides.

Method 3. Completely screwed up ignition timing (not really).

The first is the most likely. If you have blue smoke and possibly reduced performance you are looking for a broken ring(s). The chances are the problem is at (1). A compression test should reveal what is happening. If you follow the normal steps you should see if some cylinders are faulty or if they are all worn it should show up when you test with some oil dropped in the cylinder.

If it is a real knock (following from point 1 above) then it is a completely worn out engine (big ends or small ends or both are gone).

If however the ignition timing is gone wrong (faulty chain, gears or electronics) then ... sorry my timing knowledge is using stroboscopes nothing with the electronic stuff.

I have knows bad timing (valve timing) in my previous C900 to cause fuel and a lot of oil to go back in the air filter only to be sucked back in and cause a lot of dirt everywhere. Something like that could happen with a stuck valve or a faulty hydraulic tapet (thingie on the valve). Not enough though to explain all the things you describe.

I would start from a compression test. Sorry I am not saying what it involves as I am not sure of the proceedure to isolate electronic ignition systems ... and catalytic converters.

If you have a worn engine it may be worth rebuilding, if something is broken a lot will depend on damage in the cylinders.

If it helps at all. Charles

Could be. Seems a logical next step is a compression test, after which pulling the head is physically and logically next.

Well, he's also a personal friend (we've been firefighters and EMTs together for a decade or so) so I take him at his word.

What The Fuck. As in, "this doesn't make sense, what is going on here" with a "I'm a bit upset" connotation.

He's thinking rings. At 93K miles???? Again, WTF?

Ah.

Postulate 4: Massive air leak in PCV system causing engine management system to not know when to fire so it _sounds_ like pinging maybe?

He's doing one for me this morning, will know results soon.

It's just that I have this nice nearly shiny B-engine I'm rebuilding right now for the '78 99 Turbo.

Which would be odd.

Same here, that's why Bill is working on it at the moment. If it turns into a mechanical issue again (rings/valves/etc) I'm good to go, but I'm just not comfortable on the newer ones like I am on the older ones. Maybe that's about to change.

Right, and I'd probably have heard tappet noises which were decidedly not there at all.

I am hoping that it's as simple as gauge in spark plug hole and crank it? It's a DI car so it won't start running at that point, all things considered...

Yup.

It does, I appreciate your time and thoughts as always. I think we've been crossing paths on Usenet for over a decade, haven't we? Misc.rural back in the 90's, and here at least?

Dave Hinz

"Dave Hinz" skrev i en meddelelse news: snipped-for-privacy@uni-berlin.de...

I don't believe so....!

What about your crankcase-ventilation, you're sure it isn't blocked up. It's a common fault on the 9-5 and Saab has released several bulletins about it...

Cheers!

Do you have a link to said bulletins? Best I have is the article on photo.platonoff.com showing how to do the PCV retrofit. Is this a "I pay for it" update or "Saab pays for it" update? And is the Saab part number

Thanks, if this is all of the problem my day has just got a LOT better, Dave Hinz

"Dave Hinz" skrev i en meddelelse news: snipped-for-privacy@uni-berlin.de...

I'm not sure about the part number, but I can check the EPC to see. You'll have to ask Saab about the warrenty-issue.

The swede Göran Larsson, who writes alot "in here" has made a VERY informative page about the problem. You can read it here:

The car has 90,000+ miles so I doubt it's a warranty issue. I don't care so much about that to be honest, I just want to get it fixed.

He does nice work, doesn't he? (Göran, in your "tips" section the otherwise excellent translation to English is incomplete, "och" appears several times).

Dave Hinz

"Dave Hinz" skrev i en meddelelse news: snipped-for-privacy@uni-berlin.de...

Means "and", but I guess you already figured that out. ;o)

Cheers!

Yes, thanks. I can read Swedish / Danish / Nynorsk fairly well, but when I try to write it my attempts have been nicely described as "amusing".

I am hopeful that this is all just PCV plumbing issues at this point. Can I bypass the oil-trap and learn anything useful, or would that overcompliate diagnosis?

Dave

Sorry. The translation from the Swedish page was done very quickly so I could reply to your article that started this thread. A quick cut-and-paste was the origin of the spurious "och".

in article snipped-for-privacy@uni-berlin.de, Dave Hinz at snipped-for-privacy@spamcop.net wrote on 14/10/2004 17:18:

... That's Scottish :)

Sorry to hear of your problem(s) Dave. Your idea that there might be a huge air leak causing the engine management to be so confused it just fires at around the right time seems be quite a logical approach, but don't forget that simple things like spark plugs "feed" the engine management system with information. I'm not too clued up on the new(er) SAABs ... Or the older ones for that matter :)

Is there a way to "reset" the engine management computer?On DI cars that I've owned, disconnecting the battery for 15 minutes "resets" the system.

Good luck with it ... Hope the SAAB karma you've given out over comes back!

Paul

Is the knocking the sound from detonations inside the cylinders or is it the sound from a broken big end bearing, small end bearing, or a broken piston? A broken piston would explain both the knocking sound, the high crankcase pressure and the broken hoses. You have to make a compression test to see if that could be the explanation.

A B2x4 (long engine) (about 1993 and later) should fit nicely. This engine swap is done by some 9-5 owners here in Sweden as the B234 engine isn't as optomized as the B2x5 engine, i.e. it has more metal in certain places that makes it better for high power outputs.

Trying to fit one of the older longitudinally mounted engines is going to be an interesting job. They were never designed to fit a car like the

A broken piston.

Should be A B2x4 (short engine) (about 1993 and later) should fit nicely. This

No worries; the meaning is perfectly clear, I just wanted to help you with a bit of proofreading. Still waiting on the compression test...

Thanks for that, Paul. Either way, I really want to understand the root cause of all this and will share the findings with the group. If it does end up being something mechanical, _that_ I can deal with OK.

On that topic, if I do end up rebuilding the 2.3L engine in my 9-5, is there any performance updates I can do while I'm in there, or are all the performance mods these days in the T7?

Dave

I'm glad to see that you and I have come to the same next logical step for diagnosis.

Interesting, good to know.

OK, then I'll get the 99 Turbo going with that engine then.

Ouch. A PCV problem could lead to a broken piston?

in article snipped-for-privacy@uni-berlin.de, Dave Hinz at snipped-for-privacy@spamcop.net wrote on 14/10/2004 18:39:

The guys & gals here would know:

A broken piston can have several causes. The one involving the crankcase ventilation system is: * The crankcase ventilation system puts in oil in the throttle housing. * Enough oil will lower the octane rating of the petrol. * Low octane rating increases risk for pre-detonation/ping. * If octane rating is low enough then Trionic will not have enough headroom to compensate. * Pre-detonation/ping will damage piston. * Broken piston lets combustion gasses into crankcase. * Crankcase pressure increases. * Hoses connected to crankcase, e.g. part crankcase ventilation system, bursts.

I have no idea if this is what has happened to your engine, but it is one explanations that has been put forward as an explanation of piston damage in B2x5 engines.

Fortunately I have had no problems of this kind in my own 9-5, so I have no direct knowledge about broken pistons.

Look at this image: <

The piston on the left is from a low friction Trionic 7 engine. The piston on the right is from a Trionic 5 engine. Note the crack on the Trionic 7 piston. The crack starts at top left and continues down and right until it reaches the hole for the piston bolt. This type of crack, unfortunately, is not always visible after removing only the cylinder head.

Lets hope the problem with your engine is something less serious.

If I do have something bad mechanical going on, I'll take pictures so we can use it for a training aid of some sort.

That is a _very_ odd-looking piston, at least compared to the B-engine pistons I've been juggling lately.

Yes.

Not so odd. Just the way it is today. Less material and less surface towards the cylinder walls reduce friction and reduce fuel consumption. Just look at the pistons in the pictures; from the old B202 piston to a piston from a formula 1 engine. The B2x5 (Trionic 7) piston is closer in appearance to the F1 piston than to the B202 piston.

B202 piston to the left. B2x4 piston to the right.

B2x4 piston to the left. B2x5 piston to the right.

F1 engine piston.