bbalexy

Greetings. I have been using this forum for a couple years but this is my first time creating an account and making a post. correct me if I Breaking decorum.

I currently have a 1996 SC400 and I have recently acquired a 1993 SC300 with the factory 5 speed manual, 195k miles.
My intentions were to use the SC300 5speed to manual swap my SC400.

I bought the SC300 complete but not running. Using this forum I was able to get it running with little investment by Jumping the Clutch pedal switch and bypassing the fuel pump ECU.

After getting the SC300 running I discovered it had a bad water pump leak due to failed water pump bearing. I noticed that a previous owner put a radiator in the car so I felt pretty confident that they noticed a water leak, assumed it was the radiator and when that didn’t fix it they gave up and sold it.

I just got through changing the water pump, timing belt & tensioner along with cam and crank seals. Water leak solved.

The car now seems to have an intermittent misfire at idle and hesitant to build RPMs before it warms up.

Once it warms up I can stomp the gas and it will Rev up without hesitation. Once it warms up there is light steamy exhaust coming from the tailpipe.

I let the car idle for an hour or so and the temperature stays at safe levels and does not rise.

My question to you all is, what should I do with this car? I believe there may be a failed head gasket due to overheating in the past caused by loosing coolant. The only symptoms as of now that point to bad HG are the white smoke from exhaust once the car warms up. I haven’t been able to run it long enough to observe any coolant loss.

I really like the car and I’d hate to tear it apart just for the Trans components but at the same time I’m not sure if I have the time or energy to replace the HG as I have several other Projects like my SC400 and my LX470.

is the factory 5speed rare/desirable enough to justify ditching my SC4? Should I take all the good interior parts from the SC4 and give them to the SC3 and build the 2jz?

long term plans are to have a comfortable, reliable 400hp SC3/4 just as a fun project car

bbalexy

Ok so this morning was my first time driving the SC3 5speed around the neighborhood. Trans shifts through all 5 gears well. Some clunks in the suspension ( probably a blown shock).

prior to the drive I topped off the radiator. did observe some coolant loss after it cooled down so I’m like 95% sure it’s a failed HG. I’ll have to check compression once I get the time.

after I slept on it I think I may actually keep going with the SC3. I planned to build, boost and manual swap my SC4 so keeping the SC3 instead is actually less work overall because it’s already manual and the 2jz is definitely capable of my power goals.

Just sucks I won’t be able to drive it until then.

I’ve heard really bad things about HG sealing goo but would it be worth a shot until spring time? Or will it just create a big mess when I pull the motor for build?

I’ll post some pics of the cars for you all here soon enough.

gerrb

iTrader: (34)

If it was me. I will keep that 5speed sc300 and get it where it runs good .

Tallyhoe

Suspension clunk is probably an end link and not a shock. Radiator loosing coolant may be a variety of things and not always a head gasket failure. Check your radiator, remove all plastics from above it and warm it up and check for leaks. I thought I had a blown head gasket on my SC4, but it turned out it was first seeping through a corner before it got worse and started blowing out the center.

Turbostar

If you want to go for performance, I think SC300 is better than SC400. If you plan to keep it mostly stock and drive it, the SC400 is a good choice.

KahnBB6

iTrader: (5)

My vote would be to focus on the much rarer and more desirable SC300 5-speed. It's a bit faster in stock form than 1992-1997 SC400's and has plenty of potential if you want a solid JZ inline six manual platform to modify for performance.

That being said, if you do not prefer a manual transmission car then the SC400 or an automatic SC300 with a turbo build may be more suited to your tastes.

The SC300 5-speed M/T is certainly the one that gets the most attention from enthusiasts and collectors.