I just stumbled across this thread while doing some google research tonight on this particular engine.
I happen to have the G4GC in an I30 I purchased completely sight unseen as "not running" yesterday, I bought it thinking if nothing else its a set of spare body panels for my other I30 (with the 1.5L turbo diesel) and for $550 delivered I wasn't complaining.
After installing the battery from my HQ tonner, it was quick to show a complete lack of compression, across all 4 cylinders, and when it did attempt to fire occasionally the exhaust gasses are coming from the radiator cap at a rapid pace. the rest of the car though is immaculate, way too good to part out. the engine itself looks to have been very well kept, not even a weep of oil from anywhere and absolutely no sludge under the rocker cover at 270000km I didn't get a chance to speak to the previous driver as the guy selling it just flips junk cars, I suspect its been replaced.
Anyway, this week I may pull the head to inspect and see if getting the head machined and a gasket set will be worth it, I haven't pulled one of these down before but appears a lot less complex than than a lot of the newer stuff I have seen. Since the block is cast iron I'm hoping there isn't a lot of warpage there and a skim of the head should at least have it running. The wreckers locally quoted $1850 for a second hand engine (not happening for that price) , absolute worst case ill head to pickles auctions and pick up a crashed one at least you know it was running when it got hit.
Ill see if i can attach pics in a little bit.
