Timing belt

[djmarch]

Well...I'm over 60,000 miles since I last changed my timing belt so I swapped out the old with a new Gates kit today. Done this the last time with no problems, but this time my engine lugs back and forth at idle. Is it possible I got one kog off on the belt ? I verified, (I thought anyway), my timing marks when I installed the belt, and manually rotated the gears several times before I buttoned everything up. Sure isn't idling like it was before I tore it down.

By the way, the old Gates belt looked like it could run another 15,000 miles on it. My recommendation to all is when you do this job, stay away from the cheap aftermarket.

[avguy]

Not sure what you mean by 'lugs back and forth'. If it's misfire, then being off a tooth is likely, or maybe the cam sensor was hit. But if it's something other than misfire, then perhaps the harmonic balancer wasn't completely torqued down?

[djmarch]

Not sure what you mean by 'lugs back and forth'. If it's misfire, then being off a tooth is likely, or maybe the cam sensor was hit. But if it's something other than misfire, then perhaps the harmonic balancer wasn't completely torqued down?

Thanks for the reply.. A rough idle that smooths out when raising RPMs....Harmonic Balancer ?...It's torqued.... Please explain how the HB can cause this.....I was thinking about the cam sensor as well. If it is a cog off would it ok to drive it until I can tear it down again ?

[avguy]

I offered the HB as a possibility not knowing exactly what the symptoms were. But now that you say rough idle, the HB should no longer be in the mix. I've never had the timing off on one of mine, so all I can say is that everything I've read from others says no valve-piston contact would take place with it off by one tooth. Assuming that's correct, I'd be concerned about the possibility of raw gas being sent into the cat, possibly resulting in another big job and expense. Naturally that would depend on which direction it was off. If you have an OBD reader that can show you positive (lean) fuel trim readings, that would tend to make running it for a short time a better proposition. Best, of course, to get it squared away asap.

[djmarch]

Well I scaned the Aveo with my code reader and got code PO300...WOW, could be a number of things..Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked/leaking EGR valve / passages
Faulty camshaft position sensor.

I'm going to place my bet on a faulty camshaft positioner...I may have bumped it to hard while putting the timing belt cover on. I don't believe in coincidences. Ran fine before I tore in to it.

By the way, can someone recommend me a good troubleshooting scanner with CAN, and covers OBD1, and II...That software can be updated. I have a 89 firebird, 94 chevy truck, and my 2004 Aveo.