[ChoosZ]

Necessary to reset timing? Does the CAS position affect this? Engine runs great otherwise. I had a little knock before new tbelt as well but its getting worse.

 

[Zedmonton]

Necessary to reset timing? Does the CAS position affect this? Engine runs great otherwise. I had a little knock before new tbelt as well but its getting worse.

Check mechanical timing with a timing light, adjust as needed with the CAS; with Engine warm and proper idle. 15 deg BTDC is recommended.

 

[jzack]

FYI - if you find it can’t be adjusted to 15 BTDC then the t-belt may be off a tooth.

 

[ChoosZ]

Had timing checked .. its @ 16 deg- but the it pulled a code 33 and 53 / no voltage to 02 sensors.
Are there typical trouble spots in connectors / wiring? I don't want to spend hours in a shop to diagnose.

 

[jzack]

O2 sensors don’t normally have frayed wiring issues. Could be a mouse that chewed through something? Do a visual inspection of the o2 wiring runs...shouldn’t be hard on the passenger side. Driver side will be more of an issue.

It’s also possible an o2 just failed? Always a fun time getting the rusted threads to unscrew out...

 

[ChoosZ]

Ok, replaced both O2 sensors (they were really old anyways) and it seems to have more power -- however, I am still getting some knock at times, it's very unpredictable though,, I can hear a faint "rattle" in OD at low rpms. I also have some lifter noise upon cold startup which may be related?
Which direction should I pursue now?

Ps , engine has only 109K on it so it's not exactly high miles.

 

[jzack]

Lifter noise is pretty common on these engines after sitting a while. Takes a bit of driving for it to go away...

What kind of intake do you have? If stock, critters love to make nests inside since very easy to climb inside the down low intake runners. Pull the air filters and inspect.

Should also check your MAF...could need to be cleaned.

Assuming you are running the correct spark plugs too? Is ECU stock too?

Otherwise can’t think of anything else to check?