It seems to be a commonly held belief that the 100 series is overall a more reliable vehicle than the preceding model. However, I've begun to question this dogma lately. It does em like the 2UZ doesn't have as many common oil leaks as the 1FZ, and head gasket failure is far less common in the V8. But what about the heater Tees that routinely leave owners stranded, not to mention the ticking exhaust manifolds? That latter issue can cost almost as much to fix as a 1FZ head gasket - I've seen "get it out of my shop" quotes of 5 grand to replace the manifolds. This is not a common or expensive issue on the inline six. Meanwhile, the bottom end is much stouter on the 4.5, with its seven main bearings and beefy rods. The conrods on the 2UZ are undersized compared to its progenitor - the legendary 1UZ in the LS400.
The other elephant in the room is the IFS in the 100. Problems with the 8" front diffs have been more widespread than most would care to admit, presumably including Toyota. Why else would they "beef it up" with the 4-pinion change in 2000? The issues didn't appear to be resolved after that change either. If anything, they may have been exacerbated by the shockloads of the crude early version of ATRAC. There have been numerous documented cases of ring and pinion/spider gear failures on later model 100s even in completely stock form on something as innocent as a slightly snowy driveway, let alone on technical terrain on oversized tires. Front end failures in stock form on the 80 are very rare if as long as the maintenance is kept up. And as long as fluids are topped up and you don't let it overheat, head gasket issues should be avoided.
Overall they're both still fantastic, if flawed vehicles, but am I the only one skeptical of the claim that the 100 series is on average more reliable, all else being equal?
The other elephant in the room is the IFS in the 100. Problems with the 8" front diffs have been more widespread than most would care to admit, presumably including Toyota. Why else would they "beef it up" with the 4-pinion change in 2000? The issues didn't appear to be resolved after that change either. If anything, they may have been exacerbated by the shockloads of the crude early version of ATRAC. There have been numerous documented cases of ring and pinion/spider gear failures on later model 100s even in completely stock form on something as innocent as a slightly snowy driveway, let alone on technical terrain on oversized tires. Front end failures in stock form on the 80 are very rare if as long as the maintenance is kept up. And as long as fluids are topped up and you don't let it overheat, head gasket issues should be avoided.
Overall they're both still fantastic, if flawed vehicles, but am I the only one skeptical of the claim that the 100 series is on average more reliable, all else being equal?