GU 2.8 vs 3.0 questions

[Cyclone]

G'day Guys,

I am in the market for an early 2000s GU at the moment and was just after some advice from you blokes.
I don't think I would be able to afford a 4.2 so my other options are either the 2.8 and the 3.0.

What are the 2.8s like compared to the 3s, is there much noticeable difference when driving?
Also are the 3.0l's as bad as everyone really makes out in regards to engine problems? Thought I would ask here as I am sick of getting ambushed by toyota drivers telling me I should buy a land cruiser.

Any advice would be appreciated.

Cheers
Chris

[johno90]

They both have there issues, rd28 hate heat and commonly blow head gaskets and crack heads. and the zd30 can be grenade happy but you can easily buy a N.A.D kit and good servicing should last a good while :)

[Cyclone]

Righto, thanks.
I have heard that the NADS kit can also be ineffective sometimes. Is there a certain kilometer range that they usually "blow" in?
What is the average km life of the rd28 and the zd30?

[johno90]

Both up to around 200-300,000km some have gone more, some have gone alot less.

[mudski]

The NAD's is not a fix for the grenade issue. It just prolongs the inevitable.
This is a hard question. If it were me... If I found a 2.8 that had been rebuilt, or low K's, I'd go that way. Or if you found a 3ltr with a fresh motor, I'd go that way. Lol. The 2.8's are a bit slower than the 3ltr, but a few mods and they can go alright. Still no rocket ship but, nor is the 3ltr.
What I don't like about the 2.8

is its a big heavy motor with such a small displacement.
Few heating issues as stated but not that bad I think.

What I do like about the 2.8.

V belt pulley system. Yes its old school but atleast its reliable.
They sound really nice with a bigger pipe, can get up and move better with a few mods.
Cheaper on purchase price, which means more mods can be done. With the savings I would put some reduction gears in this model. Only reason I, they tend to "run away" a bit more that a 3ltr would on 1st low down hill runs. Plus I've seen these to some quite steep up hill runs in 1st low and it seems they just need that little extra maybe extra low gear to help the little motor up those hills. They still do anything a 3ltr or 4.2 would, but do struggle just a bit. In my opinion.


What I don't like about the 3.0ltr.

The sh!tty single belt multi groove belt system. Most unreliable POS on the car. Yes worse than the grenade itself. They sqeak and squeal and carry on what they get any water on them. Even with a new belt and tensioner they will do it. Not as bad as an old one but still do. The pulley bearing doesn't seem to last long, the tensioner shocker the same.
A/C idler bearing cops all the dirt and crap and prematurely wears. Just a GU thing though...
The the way the electronic motor is controlled in this motor. It seems everything you do to the motor, you need to "tip toe" around it, so you dont get the motor upset and go into limp mode.
The inevitable we all know. The GU I bought a few years ago had the motor rebuilt at 160thou K's. I bought it with about 230k on the clock. NADs put on soon after. The injector pump died at 353k on the clock. Motor came out, conversion was done. The head came off the ZD and number 4 piston was cracked. So it was ready to drop the pin. Not all ZD's are like this. You will see grey nomads driving around towing massive vans clocking up massive K's on a stock ZD and they have no issues in the world. I would think that the actual numbers on ZD's dieing to number out on the road still going on the original motor would be minimal, its just that it is quite more common for this motor to pop than any other motor. Maybe because there is so many of them around it just seems this way???

What I do like about the 3.0ltr

Small and pretty fuel efficient motor.
They rev to the moon and back with no issues.
Love the high boost.
With a few motor mods, you can get these going quite well for what they are. Some mods a bit dearer than others...
You can run a straight through 3inch pipe with no mufflers and still be under the EPA limit. Lol.

Now to put the flame suit on....Lol

In the end, you need to see what also comes with the car, drive both if you can to see the difference. The 3ltr will leave the 2.8 a dust trail though...If I was to do it again I'd go the 2.8, only because I have had a 3ltr and never a 2.8.

[mudnut]

The RD28 uses the same block as the RB30, and therefore a similar gearbox. The ZD uses a heavier more robust gearbox.

Some other problems with the RD28 is that sometimes the key in the harmonic balancer chews out, which can be an expensive repair. There has been some mention of the cam gear breaking off as well. After having said that, the RD28 appears to be a lot cheaper and a lot more reliable than the ZD.

[mudski]

I forgot about those points Craig....
Just to add to those comments. If you do end up going the 2.8 path. Its a good idea to replace the balancer keys, bolt and washer. Just so you know its been done.

[Cyclone]

Ok, thanks for all the helpful advice guys. Seems like the 2.8 is going to be the better option then and the more reliable engine by the sounds of it.
Mudski you said "The 2.8's are a bit slower than the 3ltr, but a few mods and they can go alright. Still no rocket ship but, nor is the 3ltr." What exactly are these mods?
I will be using the car for both 4x4ing and everyday use so how do the 2.8's go on normal roads? as I live in a rather hilly area and other 2.8's and 3s in other cars tend to struggle to get up them.

[GeeYou8]

I drove a 2.8 , I didn't really like it, I had owned a NA TD42 and it was similar to drive (gutless).
I ended up getting a 2001 ZD30 GU2, the biggest problem I had was the it tore the splines off 5th gear at 160000km, gearbox had a total rebuild apparently fixed on GU3. I had the radiator let go, spigot for header tank blew off, new radiator, alternator died, replaced.
Had no mods, serviced 5000km intervals went well, got 1100km on 125l tank.
It had 260000km on it when I traded it in (got $7000)ran sweet.
Graham

[Cyclone]

Righto, yeah I have heard that 5th gear problem is a common one with them.
I would still like to find out what the mods are that mudski speaks of to make the 2.8s go a bit better

[Cyclone]

So I have found out that one of my mates relos is selling a GU. It seems to be an affordable price. It is a NA 4.2.
Would this be a better option than the 2.8?
Also it is in the 300 000ks bracket, is this considered a lot for 4.2s?