Originally Posted By: ThomasJagGuy
I recently finished repairing a friend's 2003 Saturn Vue with the 2.2 Ecotec and 5-speed GETRAG manual. When it reached over 139k miles it began sounding like a diesel at idle. This was a strong warning sign that the timing chain guides were failing. The adjustable guide's plastic friction strip was broken and the chain had begun to eat into the metal substructure under it. The fixed guide broke into 5 pieces, 2 of which went down into the oil pan. The fixed guide's lowermost bolt broke off, as did the upper one in the head behind the removable plug. On his way home from work the chain jumped, bending all 16 valves. Worn timing components, a damaged valvetrain, and two broken bolts were the result, not a "destroyed engine". I removed the head and had a machine shop install 16 new Enginetec valves I purchased and they replaced the valve guides and seals then did a valve job. I reinstalled the original cams, and put in 16 new Enginetec lifters. I used a product called Semichrome and the polishing tip on a cordless dremel to polish the cam bearings, prelubing everything with 10w30 synthetic oil. That took care of the head. I couldn't get the broken bolt out of the engine so I removed the block from the top, taking it to a metalworking shop who removed the bolt and tapped it for a slightly larger custom bolt for the lower fixed timing chain guide (the one on a boss). I replaced the balance chain set & timing set with Cloyes kits (sprockets, oiler, tensioners, guides). The timing chain tensioner is of the last of three designs, the factory installed tensioner was stuck in the retracted position and was the first design version with a big "O" ring. I finished the repair off with a new Enginetech head gasket, reused the original front cover gasket and swapped on a 4-to-1 stainless header & Autolite plugs. I dropped and cleaned out the oil pan. After it was back together it purrs like a kitten, is buttery smooth, and the owner states it has more power than it ever had before. Sitting at a stop you cannot hear or feel the engine running.
Let me state that had the owner replaced the timing and balance sets at 100k miles the cost and repair downtime would have been considerably less. I didn't charge him anything for labor. Parts and contracted services came to about $900 and here again had he had the mentioned parts kits replaced the cost and downtime would have been minimal. It's a fact that nearly all I4 and V6 engines these days have plastic chain guides in them. With chains rubbing continuously against plastic it will eventually wear out. Folks, these absolutely HAVE to be replaced, there are no if's and's or but's. I think it is a bit comical that people resist having such maintenance done on a otherwise good running engine as if it will continue to run well forever. Nothing could be further from the truth. Along with the Ecotec chain kits comes a updated tensioner and oiler, these are not extras.
Omg i should be SO worried.
Fact: I know someone with approx 380k original miles on a 2008 2.2 ecotec.
The tensioners can go bad from poor maintenance and can cause sloppiness in the chain. This results in the chain beating on the guides, causing breakage. GM updated the tensioner twice to be more forgiving in less than favorable maintenance situations.
Every 2.2 ecotec ive seen with a broken timing chain/tensioner problem looked like it had tar for motor oil and an owner that couldnt be bothered by maintenance.