Hey everybody, my car was doing around 20mpg for a while, but at the last measurement it ran around 16mpg if not worse. Also performance increase is never a bad thing. I was told that replacing the timing chain could have tremendous results for both, especially since people here are used to working with belts and seem to think chains don't wear down so it probably hasn't been done since ever. But what kind of results do you guys think would be realistic to expect? Will probably replace the tensioner as well, any other tips maybe?

 

IMHO I wouldn't really expect any real noticeable gains, that is unless the chain is very stretched, but at that point you should hear it making all kinds of noise.

 

On the 60* V6's it makes a big difference. Some on here say to replace it ever 60K miles. I did one at 80K miles and it was very loose. It even took a small piece out of the chain guide.

The reason the chains don't hold up is the irregular lobe spacing of the cam. This jerks the chain tight then loose.

RBob.

 

This ^^^

I wouldn't expect to notice anything different.

The OEM gen1/2 chains stretch quite quickly. On my only hybrid build the chain was stretched to the same degree after only 20000 kms, as the old chain was that had at least 100000 kms on it. They seem to get to a point of stretch and just stay there.

The gen3 chains seems to stretch a lot less, but are not compatible with gen1/2 cams.