2003 LS 430 Motor Overheated Advice

[AndreasMet]

Hi,
I have posted a similar post over at club lexus and I found this site there.

My 2003 LS 430 with 220K miles was driven 30 minutes by my wife without fluids and stopped running. It was re-startable but had zero power. Did a compression test and here are the results:
Driver Side front to back
1 60, 2 60, 3, 80, 4 90
Passenger Side front to back
1 50, 2 50, 3 40, 4 60

I am proceeding down the path of swapping out the motor (despite some people suggesting I can fix it in-situ). I still need to disconnect the drive line and it's ready to come out. it's been easy getting to this stage, I learned a lot, and I don't mind the extra work.

I have a few questions that need some perspective:
1. 3uz-fe motors cost a lot more than the 1uz-fe. Can I drop the 1uz-fe motor/transmission into the 2003? I don't want to monkey around with modifying stuff to make it fit.
2. If the old motor is salvagble I want to use it in a rat rod. How difficult are parts to find for a rebuild?


Thanks for helping me out. My respect for these motors and cars has gone up 100 fold in the past three weeks, so I plan on being part of the community here.

 

[cribbj]

Andreas, welcome to Lextreme. These are great little V8's aren't they?

I think most of us who fool with these motors have experience with the 1st gen 1UZ and 2UZ. I don't know that many of us, except perhaps Gloverman over in NZ have much experience with the 3UZ.

I would think offhand that the 3UZ ECU isn't going to like the lack of VVTi on an older 1UZ, and it may not like the VVTi setup on the 2nd gen 1UZ either.

And if you went the other way, I doubt that a 1UZ ECU would play well with the '03 car and its newer ECU's.

IMO, I think your only viable option is to find another 3UZ engine or at least a shortblock.

Perhaps someone else can chime in with something I've not thought of?

 

[gloverman]

I would recommend sticking with the 3UZ. They delivery quite different power and Torque to the 1uz VVti.

I have run 3UZ on a 1uz VVti ecu and it went well but had a few funny little spots in the mapping which I didn't really like. I was being fussy. To run the 1uz VVti on the 3UZ ECU you would need to swap the throttle body and engine wiring loom. Power steer pumps are different , some 1UZ have the hydraulic fan pump where the 3uz has a idler unit with electric fans , exhaust manifolds are different. Sticking with the 3uz is much simplier.