What happened to my car?

[Catbox_95]

So, I was fine-tuning my SAFC-2 and doing a couple 3rd gear pulls (literally, just a couple), and on the second pull, at around 5,800 rpm, I hear this clanging noise so I let off and it's clattering REALLY bad - push in the clutch, kill it, tow it home. Pull the valve cover and ALL of the intake side rocker arms are laying around, popped off.

1 of the rocker arm's roller is split in half and the roller-bearing is sticking out. So, it this a cause of the problem, or is this an effect of another problem? Anyone ever deal with this?

I have all new timing components, i.e., new timing belt, new tensioner, new valves, new springs, locks, retainers, etc. I haven't checked (but am about to) to see if the timing belt jumped, but so far it looks in great condition.

 

[Catbox_95]

Well, I pulled the timing cover and found that the balance shaft belt is broken into 4 pieces, the crank sensor is busted, but the timing belt seems to be in perfect condition. However, the crank seems to be 180 degrees off of the cams! I can't figure out how that would happen and still have the belt seem intact and tight.

Still waiting for any thoughts you guys might have...

 

[mysticfire6602]

my thoughts? something was wrong with the tension of your timing belt, you might hav a bad auto tensioner or a bad tension pulley, or you could have been given a bad timing belt...

 

[Catbox_95]

I guess that could be the case. The belt is a new Gates belt, the tensioner is also new, and even after the incident, it had good tension.

I pulled the head. For some reason, the intake cam managed to rotate about 90 degrees out of sync. This caused all 8 valves to collide with the pistons, and you know the rest. The good news is, the valves bent but stayed together and there is minimal damage to the pistons, none to the cylinder walls, and none to the head. So I just need to replace the valves.

I still can't figure out why the balance shaft belt would shread the way it did. There has to be some connection between the intake cam getting way off and the balance shaft belt breaking in 4 places, but I can't figure out that connection.

 

[Defiant]

Your timing belt jumped, probably from eating a piece of the broken balance shaft belt. Was the balance shaft belt new, too?

 

[Catbox_95]

Your timing belt jumped, probably from eating a piece of the broken balance shaft belt. Was the balance shaft belt new, too?

No, actually it wasn't. Do you think that it could have failed and a piece of it was damaging enough to make the timing belt jump?

 

[tfoti]

Yes, the balance shaft being the cause of timing belt slipping is common. Even on a perfectly adjusted timing belt. If you decide to keep that belt it has to be replaced with the timing belt. It's also another good excuse to remove the b-shaft altogether.

 

[Catbox_95]

Thanks tfoti and Defiant. That is the only thing that makes sense to me now. It pisses me off though that I went through all the trouble of replacing all that other stuff, and not the measley balance shaft belt, and got burned.