broken timing chain

[domperignon]

The timing chain on my 9000 cd turbo broke, while I was driving, (of course) but thankfully not at high speed or rpm. What I am trying to find out is if saab has built in enough clearance so the valves don't slap the pistons. Hubby can do the timing chain itself, but do we need to be concerned about piston damage? Any help is appreciated. Thanks, dom

[boxman]

i cant say for sure but what i can say is the valves do pertrude past the head to block mating face when open so its possible that the valves and pistons have met, you wont know until the engine is dismantled i'm afraid, unless any one else out there knows for sure

[klarking1075]

The bad news, is that there is no gurantee at all that you will get away without damage on an 'intrusion' engine (i.e. the valves intrude into the piston stroke). I had the timing belt tensioner go on an 1800 Mondeo (those are intrusion engines), and all 16 valves were bent.

So don't count on being lucky - when the mondeo failed, it was sitting just above idle (1,100 rpm).

If you want to snap the timing belt on a car - certain of the Mazda MX5 engines are non-intrusion (and they are in the minority) - so snap the belt at whatever rpm you want and all you need to do is put the new belt on. Wish everyone did it that way. I guess though, they do intrusion so that if it snaps it costs a fortune to fix. Bah humbug. Back to being cynical again.

Cheers


Kenneth

[Basre]

Unfortunately .. the Saab IS an 'interference' engine.. Valves do hit the Pistons.
Even on the starter.. the Valves.. WILL.. be bent and will require replacement.. sometimes the 'bend' damages the guides as well.
With a lot of luck you 'Might' not have to replace the pistons.
Strange that yrs 'snapped' they rarely do this, usually jumping a tooth on an appalingly worn chain (same result tho :-)..
these are Tough Parts onna Saab.

[domperignon]

I was surprised too! Didn't worry a lot because of the chain, not a belt. Upon examination, the belt did not show undue wear, don't know what happened, but sure wish it hadn't. Love my car, love the "get up and git" and the luxury it affords. Hubby swears he's gonna make a weinie roast out of it, but over my dead body! lol If it jumped a cog, it did it at the same time, because I never had trouble with starting, running consistantly, and, of course, acceleration. (my personal favorite!)

[klarking1075]

Sorry, I must be old fashioned - I always knew them as 'intrusion' rather than 'interference'. I guess as long as we all know what I'm talking about.