Was the 2UZ-FE an improvement on the 1FZ-FE? (1 Viewer)

[SaturnAscends]

Although I did find my 1FZ-powered Cruiser charming in its own right, it had its fair share of oil leaks which I understand are not uncommon on the old tractor-style inline motors. In researching the 2UZ, it seems to leak and burn far less oil.

Even at the same age and mileage, they don't seem to have as many common oil leaks and don't seem to need top end rebuilds at nearly the same rate as the old 1FZ. I wonder if this is specific to a V8 design as opposed to an inline 6?

I could be wrong, but from my research, they appear to be more likely to deliver 300,000+ miles of relatively trouble free motoring without being torn into (apart from the idiotic starter location and cracking exhaust manifolds, along with the timing belt).

On the other hand, the 1FZ apparently has a much stronger bottom end, with the inline 6 being an inherently more robust layout. The connecting rods especially appear to be far stronger than those in the 2UZ, with those being a somewhat weak point in the 4.7l.

TL; DR: Is the 2UZ-FE a more durable and reliable engine than the 1FZ, all else being equal in terms of age, miles, maintenance, etc.? Why or why not?

Thank you for reading.

 

[ceylonfj40nut]

2UZ is night and day better. Smooth, powerful, reliable, durable. Hard to compare an in line 6 to a v8. @Zjohnsonua has been trying to bring me to church lately on this. I am toying with the darkside with LS flavors.

 

[SaturnAscends]

2UZ is night and day better. Smooth, powerful, reliable, durable. Hard to compare an in line 6 to a v8.

I was wondering if the V-layout is a better design overall that predisposes it to less issues. The 1FZ is undoubtably a venerable motor but it can be a pain to maintain nowadays, especially since they were never especially common stateside.

Then again, are the weaker connecting rods in the 2UZ a concern at all? From what I can see the 1FZ technically has a stronger bottom end and is easier to work on, but that's about where it's advantages stop AFAIK, apart from maybe more usable low end torque on the trail..

 

[Jack90210]

The weaker con rods only seemed to be a problem with the addition of the TRD supercharger. I seem to remember that Toyota switched over to forged pieces in the 2UZ at some point, but I could be remembering incorrectly.

 

[hickuptruck]

My 2uz doesn't burn or leak a single drop of anything. Also, the 2uz cooling system is way more stout than the 1fz.

I've never heard of con rod issues ever on the 2uz.

Head gaskets seem to be a reoccurring issue on the 1fz. Never on the 2uz. 2uz is imo Toyotas finest hour. It comes from a 1uz motor in which more was deemed the most reliable dohc motor ever in the 1980s. 300+ million was spent developing the motor.

 

[BullElk]

I do not know the nitty gritty details but I have owned and driven both for many miles and years. The 2UZ was and is much improved over the 1UZ. No question about it.

 

[ceylonfj40nut]

2uz has a few more pieces to deal with on the front face. I must admit I like the chain driven variants of the Toyota engines. The timing belt is solid in the 2UZ but needs to be replaced. The 1fzfe is simpler to work on and has a timing chain.

 

[SaturnAscends]

I do not know the nitty gritty details but I have owned and driven both for many miles and years. The 2UZ was and is much improved over the 1UZ. No question about it.

Do you mean the 1FZ or the 1UZ?

 

[BullElk]

Do you mean the 1FZ or the 1UZ?

Correct…. 1FZ

 

[FZJ80Cruiser]

For sure. Especially the 2UZ paired with A750F.

 

[newbielx470]

Just out of curiosity, have there been 1-million mile 1FZ engines reported/famous (in North America)? I've heard 1-million mile 4.7L and 5.7L from time to time, but haven't really heard that for 1FZ. (I know the "1-million mile" is kind of extreme case, but somewhat of an indicator of the reliability/longevity.) I'm sure there are some outside the US where 1FZ is a lot more commonly seen

If it's also a very reliable engine, I'd expect a lot more 1-million mile 1FZ given its age and also the trucks overall are less complex.

 

[BullElk]

I was always under the impression for some reason the A442 in 80 series was the most bulletproof of them all. Don’t know the truth but seems I read that as truth.

But really can’t tell when none of my a343f or a750fs have ever had issues.

 

[SaturnAscends]

I was always under the impression for some reason the A442 in 80 series was the most bulletproof of them all. Don’t know the truth but seems I read that as truth.

The 442 is just a big antique slushbox that robs about 25% of the drivetrain’s power. But they are fairy immortal since they’re too dumb to die.

Some will say they’re way better than the 343 and the later transmissions but I’m not convinced of that. The 343 and 750 seem pretty unstoppable too.

 

[J1000]

The 1FE has its roots in post-WW2 Chevy inline 6s.

The 2UZ has its roots in the $1bn LS400 project.

Yes the 2UZ is better.

 

[97 AZ LC]

The 1FE has its roots in post-WW2 Chevy inline 6s.

The 2UZ has its roots in the $1bn LS400 project.

Yes the 2UZ is better.

Remember he didn't ask about "better", he asked about durable and reliable. Better is highly subjective, subject to individual opinion. It's possible that 2UZ is more durable, that is long lived, but it's a close call. The 1FZs are awfully stout and the later ones seem to be less prone to head gasket problems. They are both so long lived that it may be too soon to be asking the question. Let's wait a couple more decades.

But on the subject of reliability I don't think the 1FZ can be beat. Modern electronics cause too many sudden inexplicable no-run failures, often resulting in a tow. 1FZs limp so well. Engine reliability has to be considered in the context of the electronics that make them go down the road. If your ECU fails or your VSC system is braking on one side of the vehicle and running you off the road there's little consolation in knowing that your head gasket is solid. Your modern engine is a co-conspirator in the problem. Modern electronics are not without compromise and are generally shortening the useful and economic life of automobiles.

 

[GTV]

One must ask, has any LC engine been worse than the one it replaced?

 

[hickuptruck]

One must ask, has any LC engine been worse than the one it replaced?

Hmm maybe 1HD-FTE and then it's successor, the 1vd-ftv which has seen some engine failures and the airbox getting dusted.

 

[Njck22]

1fz is a simpler motor. If I was in a country that lacked specialized repair facilities I would want a 1fz. Starter is easy to change too.
2uz wins in every other category. smoother, more reliable, cleaner, etc

 

[beatle_bayly]

Funny how different countries have different views on the same things. Here in Oz I reckon a knowledgeable jury would side with the 1FZ over the 2UZ for reliability and longevity.

IMO, while the V8 rumble is great, and no doubt the 2UZ with A750 is much nicer to drive, I'd feel much more comfortable driving an FZJ80 with manual transmission into a war zone than I would a 100 series V8 Auto

 

[willyroo]

Now 2 x 2UZs + A750 with 1,000, 000 miles (1.6M kms). Having had both, 2UZ for me...

Million mile Tundra 1
Million mile Tundra 2

I remember when the FZJ80 was released with the mighty 4.5 litre inline 6, Toyota's ads pointed to it being able to be bored 30 thou' up to 3 times.

Oh and fuel consumption?