lamb03

90 ls400 with around 300k miles



I posted here a while back after the connecting rod bearing on cylinder#3 spun/detonated, when i pulled the bearing out it looked like it was smashed, the crank and everything around it i couldn’t see any scratches but i lightly sanded the crank and cleaned it with brake clean, put a coat of oil on the crank and the inside of the new bearings and i also cleaned the oil pickup and everything below.

But i started it up sounded perfect, drove it to the gas station and drove it across town no issues so on my way home i brought it up to 80mph pretty quick and when i slowed down i heard the bearing fail and i’m pretty sure it detonated again,

I already have plans for a new 1uz but if there is any chance of saving this one it would be a cool side project once i have it out.

Check out these bearings New vs Old

paulo57509

Once engine bearings spin, what ever is in contact with them is fubar. The diameter of the bore where the bearings are housed gets enlarged, the bearing loses it's "crush" (the force that keeps the bearing from spinning) and the replacement bearing will spin again in short order.

Save a 300k mile engine? Use it as a core exchange for the rebuilt.

400fanboy

Just think... all of the fragments of the bearing that aren't in your hand are circulated, at speed, throughout the rest of the engine. The bore will be scoured throughout the engine as the metal shavings get circulated. So that also hits on the oil pump, and there probably are pieces lodged in the oil passages.

And since the piston rings no longer have a correct seal they are potentially scraping the cylinder lining too so there goes your hone... And and and and and and

The motor is dead man. Maybe there are pieces of it saving which weren't damaged, but even then, Paulo is right at 300k miles what's the point.

lamb03

yeah you guys are right it’s time to let go
time for a swap

pucks18

I've always been interested to ask someone knowledgeable like you who is dealing with a 1uzfe/2uzfe. Where and what brand parts do you use for the bottom end bearings, rods etc? The factory ones are obviously of amazing quality, and the metallurgy is amazing enough to last 500k miles.. and I'm worried that no aftermarket supplier would be able to touch the years of r&d to develop this engine. I'm also worried about oem parts like rod bearings from the lexus dealer not being the same quality as they were at the factory. For example the radiators from the dealer in 2023 are NOT the same quality as the ones from the factory in Japan back in the 90s.. but yea where do you source you parts? Am I wrong about aftermarket suppliers not being the same quality?

400fanboy

You don't have a choice. You have to buy what you have to buy. In theory, OEM parts should be manufactured to the same standards today as they were back then. But I can't say one way or another if that's true.

The aftermarket for this car goes in two directions.

1) performance, solid bushings or motorsport\drift\VIP applications.

2) cheaper purchase price

Nobody is making more durable, or even comparable to OEM quality components. This often true for other cars as well to be fair, but it's not as overwhelming and there are many exceptions. It's a universal rule for any LS400 component.