My passenger side valve train has been making a rattling noise on and off for weeks, its now getting to the point it rattles most of the time. I removed the valve cover and checked all the valves, nothing is loose. I thought it may just be a pulley or a tensioner, but the noise is definitely coming from inside or under the valve train.

I was thinking I may have a loose timing chain? When i wiggle the crank shaft, it moves about 1/2 then makes mild "click" before it starts moving the belt system. Is the tensioner on the timing chain adjustable? or do i need to just replace it. I just had the front of the block apart too dangint when i did the pump and plenum..

Any ideas? Am I totally off with the timing and could it be something else making all this racket?

thanks!

 

V-8's didn't have a tensioner stock, and the morse style chain is prone to stretching. Replacement is about the only option.

You may also have some lifters failing there, that would give you the tick you are describing... (or, and exhaust leak....)

 

There is no chain tensioner on a stock motor unless you put one in.

Wouldn't hurt to put a double roller timing chain on it as the stock chains wear out rather quick and get some significant slack in them.

 

Before I did the plenum job on my truck it had the same noise that I thought was "valve rattle", and while it was making the noise it was also a gutless pig... Anyway... Have you fixed your plenum yet?


After the plenum fix I have the same noise every now and again, although it's much quieter and has no ill effect towards power, I'm thinking it needs another bath in SeaFoam.

Or could what I though was valve rattle be spark knock?

 

I did the plenum. Truck has all its power. I could burn the rubber off my 37's in minutes if I wanted. =p

Lifters and valves etc all looked normal. Clearance and torque was good even [i only checked the passenger side] but there was one lifter not quite pumping oil like it should. but it wasnt the source of the noise. I couldnt really narrow it down to just one lifter when i was scoping them. sounded deeper [why i thought about the chain]

 

Double roller timing set with tensioner www.mopatsracing.com. Tensioner is direct bolt on.

I suspect lifters failing.