3L
Absolutly do not buy an early 3l unless you want a 8K rebuild bill. usally between 150-200,000km. the later ones are ment to be better but it is still basicly the same engine. Every thing from melted pistons, cracked/coroded heads, cracked blocks, failing injector pumps ($3000.00). I know 2 people that own 3l, between them it has cost over $12,000 in repairs and this is doing the remove and refits themselves.
slightly beter performance and economy than the 4.2 in standard form.
The 3L are dearer than the 2.8L but are quite cheap to buy.
2.8L
this is a good fairly reliable engine but it is put up with a hard task pushing a 2.3T patrol around. Off boost they have no go at all. when on boost they go ok. Not as much performance as the 4.2l and have no certain on fuel economy but think it is about the same as the 4.2l
The 2.8's are fairly cheap to buy.
4.2L
This is an old pushrod engine. Put a 3" exaust and dump pipe on they will equal or better a 3L in power but use slightly more fuel (negligable differance) However they are almost unkillable.
The 4.2 are a bit scarce and you will usally pay good money for a decient one but in my oppinion it is definanly worth the extra $$$ for the reliability and simplisity of them especially if you intend on keeping it for a while.
My father has a gq (non turbo) that has done over 700,000km and has not touched the engine except for survices and it is still going strong. well past due for injectors the be done thou as the fuel economy is not what it use to be.
A friend has a gq 2.8L. he rebuilt it when he bought it 2nd hand. cracked head replace, turbo rebuilt, done injectors and went right thru it at that time. I beleave it was due to being over hearted by previos owner. I think it had done about 200,000km then and now has almost 500,000km on it with no further hassels.
Just my oppinion and experiances.
