Gs400 Engine In Ls400?

Harbison · February 4, 2015

Can I replace the engine and transmission in my 1998 LS400 with an engine and transmission from a 1998 GS400?

jainla · February 4, 2015

I think you probably could although I'm not sure why you would; they are almost identical. The mounts may be different; and some of the ECU programming might change.

Harbison · February 4, 2015

My LS threw a main bearing. Camshaft is fine and I could replace bearings but at 250,000 miles I wondered if I should look for lower mileage engine/transmission. The local junkyard has 98 GS400 which prompted post. Are 98-00 only years I should look for? Thanks

Exhaustgases · February 5, 2015

Any idea why the bad bearing? Was it the oil used, racing the car or what? You just don't hear about LS engines doing that sort of thing even with over 300,000 miles on them.

billydpowell · February 5, 2015

to answer your question YES, 98-00

jainla · February 6, 2015

Ouch. Poor car.

Yes to billy's point 98-2000 should be more of a drop in upgrade. The same car got the 4.3L engine in 2001 but there may be other mods. Some people over at the 'other' forum (ClubLexus) might have some input; I see they seem to do more mods like this on a regular basis.

Harbison · February 6, 2015

Exhaustgases, I'm not sure of the cause. It was basically a one owner car bought by a lady realtor. She put almost all of the miles on it and gave it to her housekeeper who I bought it from. All maintenance done by Toyota dealer. I don't think it was from hard driving. Oil had been recently changed.

VBdenny · February 6, 2015

Hey Harbison. I would think that a 1998 GS and LS engine would be identical. Only the body style is different. Having looked at the SC400 engine I believe that is also the same. Man, bad bearing on a 400 engine? something I've never heard of happening. My guess is that the elderly lady dropped it off somewhere for an oil change and someone forgot to add the oil after the drain. Started it, noticed the light on and then remembered to add the oil. I've seen that happen. Had friends who had their oil changed at a Jiffy Lube, drove off heading to Florida and the engine bearings let loose in South Carolina. The damage was there, just took awhile to manifest into a disaster. Of course Jiffy Lube denied any responsibility.

Sckit · June 6, 2023

Hey yall so i got a 98 ls400 the trans recently blew on me and i was wondering if i could use the same 3rd gen trans out of gs and sc400's in my ls400 i dont mind swapping the harness and little stuff as long as it works