[initiate]

I just did a head job in which I replaced my timing chain. I had bought an ENGBLDR chain with tensioner and steel guides, but when I was doing the install my chain bound on the lower sprocket and busted so I had to go out in the middle of the weekend and pick up a chain and lower sprocket (on the crankshaft hub) from Kragen. The ENGBLDR tensioner, camshaft sprocket and steel guides stayed in.

Ok, so I've been running for about 5-600 miles since the change. Within the last 100 miles or so I've noticed a rattle in the engine just when I start to apply throttle at very low RPMs. Kinda like a really fast rattle-can sound. The sound is NOT there at idle, it is only just as I start to accelerate in 1st and maybe 2nd gear and then once I get to higher RPMs it goes away (I only hear it for about 1 second).

I was thinking that it sounded maybe like the timing chain was not tensioning fast enough as I started to accelerate and it is rubbing against that steel rail. Does that sound like a probable diagnosis? Is there any danger here or is that normal? Like I said, brand new chain, sprockets, tensioner, everything, although the chain wasn't the best.

 

[ohgood]

I just did a head job in which I replaced my timing chain. I had bought an ENGBLDR chain with tensioner and steel guides, but when I was doing the install my chain bound on the lower sprocket and busted so I had to go out in the middle of the weekend and pick up a chain and lower sprocket (on the crankshaft hub) from Kragen. The ENGBLDR tensioner, camshaft sprocket and steel guides stayed in.

Ok, so I've been running for about 5-600 miles since the change. Within the last 100 miles or so I've noticed a rattle in the engine just when I start to apply throttle at very low RPMs. Kinda like a really fast rattle-can sound. The sound is NOT there at idle, it is only just as I start to accelerate in 1st and maybe 2nd gear and then once I get to higher RPMs it goes away (I only hear it for about 1 second).

I was thinking that it sounded maybe like the timing chain was not tensioning fast enough as I started to accelerate and it is rubbing against that steel rail. Does that sound like a probable diagnosis? Is there any danger here or is that normal? Like I said, brand new chain, sprockets, tensioner, everything, although the chain wasn't the best.

maybe you have too much timing advance ?

are you certain you didn't put the wrong bolts in the portion of the timing cover over the oil tensioner (chain tensioner) ? if the wrong bolts are used it's possible to bind the tensioner, and allow slack.

 

[initiate]

I don't trust myself 100% on anything, but I was pretty careful with the bolts. Will too much timing advance cause this? I don't really understand how but that's definitely a possibility. I've been fooling around with my ignition system so I need to set the timing again anyway. I will try and let you know if that helps.

By the way, how do you keep the spot you make on the crankshaft from jumping around underneath your timing light? The first time I tried to time my engine, the mark was rock solid when I had the timing dialed in. But every time since then it jumps 0.5-1 degree back and forth, like it's all jittery. I have to just get it as close to the spec as I can.