Not a new topic but I thought I'd add my expreriences. Looks like swapping a 2006 to 2008 Engine into a 2004 to 2005 Aveo is a successful swap.
My situation is I had a premature T-Belt faillure as the replacement only had about 45,000 km on it which doesn't even reach the recommended inspection interval. I opted to replace engine although I considered just rebuilding the cylinder head. Pistons definately hit valves so I figured engine replacement was the best option.
The belt that failed was made or at least imported by KMM... I'm now using Continental (Contitech) in replacement engine. Water pump, tensioner, and idler wheel were also replaced prior to failure (for those wondering).
The engine I used was a 2008 1.6 litre Pontiac Wave motor with about 50,0000 km on it. On start up the valves were very noisy from the engine sitting too long but this went away by increasing the revs to about 1500 rpm for a couple of minutes. The engine was difficult to start also. Check Engine Lite (CEL) came on and turned out to be P-0300 (random misfire) - to be expected with engine replacement according to GM shop manual.
Notes for Swap (into earlier Aveo 04 or 05):
Use 04/05 intake manifold, throttle body, and fuel injectors onto 06 thru 08 engine.
Use Knock sensor and Crankshaft position sensor that belong to 04/05 engine (or at least cross-reference)
To be really safe use all sensors from old engine (assuming you had no CEL in old engine) although most are the same.... I only observed / cross-referenced some changes with Crank and Knock sensors.
Now the issues I had:
Firstly I found gear oil in the bell housing of my 5 speed Aveo transmission.... replaced shaft seal in housing (not too hard) just have to remove seal retainer (3 bolts) and replace seal (similar to half-shaft seals). Cheap at about $5 but was not inventoried and had to wait 8 days for parts to come from Detroit
Secondly, GM for some reason didn't manage to do Crankshaft Re-learn procedure (although I paid about $150). This led me down the path of checking for other faults (vacuum leaks, ignition system, etc). I didn't spend too much time on this as I started to doubt Crank Re-learn that GM "did". A local shop (not GM) managed to do this procedure for only about $40 using a Snap-On calibrator.
Thirdly, the PCV system changed from earlier to later engines. This can be noted by a large diameter (maybe 1" tube) that runs from crankcase to top right side of valve cover. And this, I believe, is the reason earlier 04/05 engines (head and block) are NOT interchangeable with 06 to 08 engines (head and block). The PCV system became internal in later engines. To note the differences and how to connect PCV system of 06 thru 08 Engines vs 04 thru 05 Engines I Googled images of both these engines to compare routing of PCV system. The 2008 engine I now have is more what I am used to in terms of PCV systems with other cars.
Final notes:
Just be careful labelling everything as not too much slack in any wiring (needs to go back the way it was) No need to swap computer and use 04 or 05 wiring harness with 06 thru 08 engine.
Overall a relativly easy swap without the issues of the Crankshaft Position Re-learn which turned out to be the biggist pain. I did run the car for a few weeks with the check engine light flashing and it did run fine...
In closing I am seeking a refund of $150 from GM for the Crankshaft Re-learn that was not accomplished and caused undue headache.
In the end a happy swap and I will be checking T-belt at 25,000 km or less!
As an update GM refunded $150 for attempted Crankshaft re-learn procedure today! Mystery why couldn't get done there but seems it can be a bit tempermental that procedure...