V6 Timing Chain Replacement

It looked like the timing marks were still aligned, so I don't think it jumped. I guess I probably should pull the pan.

I pulled apart the oil pump, and I found some light grooves in the outer part. Just enough to barely feel with a fingernail. I will use some fine sandpaper on a flat surface to smooth it out.

My main holdup now is the seal on the harmonic balancer. I think I need a dremel or something to get the old one out.

 

You mean the seal in the timing cover? Just pry it out. In the past I have used a crow bar to remove old seals. Just don't pry against any surfaces you can damage.

 

The original seal is rope with a metal retainer that is swaged in place. Remove the rope seal first, it should just pull out, then drive out the retainer from the outside inward with a punch. I support the timing cover with wood blocks. Use a dremel or similar to carefully remove the remains of the swaging and then carefully drive in the new seal after thoroughly cleaning everything. This is of course if you are eliminating the factory rope seal and installing a neoprene seal. Which I highly recommend.

 

just curious how you knew the chain was shot? timing jumping around? I rotated my engine back and forth and didnt have any slop watching the rockers. is that a good way to tell

 

It started to rattle and clatter. You can also check by turning the crank back and forth with a wrench and looking at the distributor rotor.

 

Getting close to being finished. I reassembled the front cover and all the accessories. While the cover was off I sanded the oil pump plate to remove a little scoring, then packed it with petroleum jelly.

I pulled the oil pan off and found all the teeth inside. there was also a little silvery gray sludge in the bottom. I'm hoping thats nothing to be too worried about. I wouldn't be surprised if this was the first time the pan has ever been pulled.

 

The nylon covered cam timing gears were responsible ruining a lot of Pontiac V8's in the '60's & '70's. When the nylon coating fell off it and allowed the cam to get out of time with the crankshaft, then piston and valves tried to occupy the same space at the same time-No Bueno! This usually lead to pulling heads and replacing bent valves in addition to timing chain and cam sprocket. "It started to rattle and clatter" I hope you haven't experienced the same thing.This may be where your compression went. Good luck!

 

If it were me, I would install the gears and chain to TDC and leave the front cover off. I would then check the engine compression. If good then complete the assembly.

 

Oops, I forgot to update this thread when I finished up. It was starting to rattle pretty bad when I took it apart, but now it runs smooth and quiet.

Walt, if I had done the compression test before assembling and compression was still low, what would I have done at that point?