aradmahogany

I believe the chain in ecotecs is something to replace if there is a problem; best way to get near unlimited life out of them is to use good quality oil at the proper intervals. Also, there was some change to the guides in later years that made them a bit weaker (I think). At any rate, though chain failure in these cars is one of the most talked about subjects, its actually one of the rarest issues to have. Plenty of HHRs out there with hundreds of thousands of miles with original chains and guides. Unless people have the money or arte well versed in the art of chain and guide replacement, they are setting themselves up for a nightmare by attempting to replace the chains as a "regular maintenance item". Also, the OEM design of the water pump gives it near infinite lifespan. Regular maintenance of oil and coolant keep these cars running damn near forever.

Still, good write up!

UWZerokoolX

There were two charges to the timing chain tensioner and a bigger timing chain oiler port.

donbrew

The pre-2006 Cobalts/Cavaliers had a huge problem with the timing chain. This is the second time I remember somebody having a problem with only the balance chain.

The tensioner was actually a part number consolidation. The VVT engines always had the hydraulic kind, but the non-VVT had mechanical with oil ports anyway. Somebody decided to just consolidate the part numbers like parts books like to do.

Oldblue

Our 2003 2.2 Ecotec, 230,000 miles, original chains and guides and tensioner.

UWZerokoolX

Yep, about the same as mine. That's why I recommended at around a 180k seems failure comes from there on up.

I believe mine was kind of a mixture. That black guide has been broken for a while and that timing chain had been grinding up on that bolt for quite some time. (Reference pictures). Now I found pieces of that black guide and parts of the sheered bolts in "strategic" locations that might say the timing chain assembly was the overall issue and caused the balance shaft chain kit to fail. Because when I shows the techs the pictures and brought them in the gear at the multiple dealers I went to hunting for those darn bolts, they were astounded by the balance shaft system failing like that. They all said, it's usually the timing chain kit that fails. But it's best to do them both since you have it apart.

Oldblue

Yes, we always suggest to change both and the water pump whilst you have it apart, your sleeves rolled up and your hands dirty!

UWZerokoolX

Okay guys, this Friday or Saturday I am running oil flush through the engine and changing the oil. Wife is complaining that the car is still misfiring a little but I am betting it's just the metal shavings clearing out of the cam phasers and messing with cam shaft positioning solebouds, so I am going to swap those again and hope that it resolves the issue.

I need a few serious opnions...

That missing bolt was never foubd, nor was the other part of that missing balance shaft gear. I think I can rightfully assume that they fell into the oil pan.

Does anyone think I should drop the oil pan and get them out? Or just leave them? And is there anything else I should replace or be looking for?

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GALLANTSIRGARY

I ran a posting today myself for the same kind of issues sort of. My problem turned out to be the balance shaft chain tensioner collapsed so there was no tension on the chain. Chain was jumping the water pump, overheated into limp mode and being an SS, Turbo was right in the way of 3 bolts in the thermostat housing...replaced everything you did. 3.5 hours to get that housing off, and 3 more to get it back on !!! 3.5 days of wrenching only to discover the head gasket blown...grrrrrrrrrrrr

RJ_RS_SS_350

2.5 year old dead thread....

Oldblue

Head gasket , that’ll give you access to clean the intake valves , I’d order ARP head studs or at least new head bolts.