I just had my VTCs rebuilt last weekend, and when I got to the point of reinstalling the rear VTC, the chain would stay loose on the side the VTC is on if I had both sprockets lined up to the timing marks. Also, as soon as I applied tension on the chain, both sprockets would move half a tooth, and stay there. Basically, the front sprockets line up fine, the rears don't. I turned the engine by hand, and I didn't feel anything stopping the engine from moving, nor did I hear any odd noises. Is this normal/passable, or do I need to have them exactly lined up?

 

Did you mark the chain to the specific tooth on each sprocket before removing?

 

it can have slack in it because of the tensioners but you have to align it correctly or it will be out of time. If you marked it the marks have to align correctly when it goes back together. If you just went by the silver links and dots then they have to align correctly. It will be kind of hard now that you have moved the engine already but I guess you can keep rotating it until the silver links align with the dots and move the cam sprocket to match it.

 

rotate the engine forward, and as long as the rear cams line up perpendicular to the valve cover mating surface when the engine is at TDC, you should be okay.

what sucks is that it's impossible to have the botom timing covers off once you put the heads on.

 

Ok, here's an update. The rear bank lines up fine. But on the front, the timing marks don't exactly line up, but are just to the left of the timing arrows on top of the cams. IIRC, that's how it was when I took the VTCs out. Should I go ahead and put everything back together, or do I still need to ensure that the marks line up exactly?

Jeff: I didn't mark the chain, but I kept track of the exact links where the timing marks would go.

 

I ran into this problem during headgasket replacement...it seemed that the cam was 1 tooth off........I loosed the cam caps and manualy moved the cam 1 tooth to correct the timing...when the chain and cams line up correctly, there wont be any slack in the chain