96' 850 timing belt snapped

Cook.p.michael · Post by **Cook.p.michael** » 13 Mar 2017, 13:13

Sooooo I didnt know that the cams should be able to be moved by hand, before i put the belt back on after the head gasket job, they wouldn't budge a bit. So to be clear, cams should be able to move freely? I couldnt find a TB in town, theres one where I am going in an hour, ill be gone for the next 5 hours and then work on it late into the night. Nothing can sound sweeter to me than the sound of my engine starting, my lack of transportation is the root of almost all my stress in life right now so im sure you guys get how badly I want to finish this project. Im glad to have gained so much knowledge from the hands on experience and research ive had to do to get this far though, i hadnt changed my own oil before i started all this. So I take off the upper cylinder head, oil the journeys, then do the anaerobic gasket, do the 40 bolts, and put the belt back on and time it?

bugs11 · Post by **bugs11** » 13 Mar 2017, 14:09

I'm pretty sure I hand spun the crank 2 or 3 times after putting on the timing belt when I replaced my head gasket. The crank bolt needed a big socket as I recall, 3/4" drive. I turned it by hand to make sure nothing hung up or made any funny noises. I do remember lubing the cam journals with assembly grease - at least that's what comes to mind a year and half later.

bugs11 · Post by **bugs11** » 13 Mar 2017, 14:20

The timing has to be done before installing the timing belt. Line up the crank, then line up the cams before installing the cams. The cams have to be locked together in the correct timing position before installing. That's how I did it on mine. I lined the crank and cams to the timing marks, locked the cams (front and back) together before removal, left them locked together until after they were back in and the cam cover was bolted down.

Post by **erikv11** » 13 Mar 2017, 19:20

Cook.p.michael wrote:Sooooo I didnt know that the cams should be able to be moved by hand, before i put the belt back on after the head gasket job, they wouldn't budge a bit. So to be clear, cams should be able to move freely? I couldnt find a TB in town, theres one where I am going in an hour, ill be gone for the next 5 hours and then work on it late into the night. Nothing can sound sweeter to me than the sound of my engine starting, my lack of transportation is the root of almost all my stress in life right now so im sure you guys get how badly I want to finish this project. Im glad to have gained so much knowledge from the hands on experience and research ive had to do to get this far though, i hadnt changed my own oil before i started all this. So I take off the upper cylinder head, oil the journeys, then do the anaerobic gasket, do the 40 bolts, and put the belt back on and time it?

Yes, each cam should definitely be moveable a little bit by hand with the timing belt off. Maybe not very far, because there are valves and pistons doing that dance, but for example the exhaust cam has an annoying tendency to rotate several teeth out of place during a timing belt change.

Also be sure the cams go straight down into place when you tighten the cam cover. If the cam guide disc is not seated properly in the head, the cam will not spin. Similarly the cam cover has to come straight up or the same discs will get wedged in the head; those slots can crack pretty easily.

I always use some kind of cam lube product, or engine assembly lube grease, on the cam lobes. Examine the bearing (head) surfaces closely for damage when you get in there.

Beware the Gates timing belts, several people have had trouble with them. Fine to get you out of a punch but don't use them long term.

Post by **tryingbe** » 13 Mar 2017, 19:43

Cook.p.michael wrote:One more thing im curious about, wouldnt the metal of the valves being bent by the pistons be loud enough to hear? There was no sounds like that if it would have been audible.

No. You won't hear it over the starter.

I think you will find bent valves.

Cook.p.michael · Post by **Cook.p.michael** » 14 Mar 2017, 13:50

So gentlemen, i messed up, see that hole? That's where I dropped one of my upper cylinder head bolts, since then I realized I need to put a rag in it. Anyone know if those bolts are magnetic? I will go to an auto parts store and get one of those magnets on a stick if someone thinks it will work. If it doesnt, any ideas on how to get it out? It looks like a major choir to take that whole part out just to shake a bolt out. Thanks

Post by **Clemens** » 14 Mar 2017, 13:56

The nut most probably is magnetic. If not, there are claw shaped grabber tools that can pick up non magnetic things.

Cook.p.michael · Post by **Cook.p.michael** » 14 Mar 2017, 14:07

Thanks!

Post by **abscate** » 14 Mar 2017, 14:47

Magnet will get it. I got a great one at Lowes which I used 28 times doing by BMW crankcase service

Post by **ZionXIX** » 15 Mar 2017, 05:54

abscate wrote:Magnet will get it. I got a great one at Lowes which I used 28 times doing by BMW crankcase service

Only 28?