Driving with engine running smoothly, gets very rough, can threaten to stall


Jun 11, 2008
2004, Chevrolet, Aveo, L91 E-TEC II 1. 6L DOHC, 16 valve, 4 cylinder, 42,300 mi.
Without any indications previously, the engine started to run extremely roughly, threatening to stop running. It could not accelerate and the check engine light went on. We had it towed to the dealer who replaced plugs, an element (GM PN 96536696), a valve (GM PN 96495288) and used or replaced a "cleaner" (GM PN 88661011). They said they performed a tuneup (no details on invoice). They claim that they found no codes. A PCV kit was ordered and installed. They recommended we use certain brands of gas and and cleaner every 3 fillups to remove deposit from the fuel system. All this has not improved the situation one iota. The engine continues to act up while driving "whenever". We had it serviced at another dealership about 4 mths later. They recorded a code P0300, cleared it and "road tested" According to them, the engine did not act up for them. However, on the way out of the parking lot, it started up again with the engine bucking periodically with the engine light going on. The light would go off until another episode of the bucking action. Since then I looked this up and found TSB 050601030 dated Sept. '07 (1. 6l l91 intermittent misfire cold during deceleration or steady state highway driving after cold start with dtc's p0300, p0700, p1781 and/or u0401 set (replace valves and valve stem seals) *tt updated 11/02/07 *nj
However, other owners have implicated coil packs (electrical) and fuel filters (mechanical). I but need some advice as to how to determine what the diagnosis is. I can't rely on the dealer since they never admitted to knowing about any problems and seem to be just trying things until something works. By that time, we will have run out of money and perhaps still end up with an undrivable car. But if can go to them with a good understanding of what needs to be done armed with the right TSB, then I might be able to get them to fix this.


Dec 8, 2006
First of all, if you went to two GM dealerships, and they did not solve your problem, you should have gone back to them and told them what they did did not fix it....second, if they have not fixed your vehicle to your satisfaction, get the number of GM Customer Assistance....should be in your owner's manual or call any GM dealer for the number....tell them your problem...that you paid for repairs that did not fix the vehicle....and you want some action...complain!