SC400slide

iTrader: (11)

Had a similar false diagnosis on a 96 SC400 I had several years back. Was told it was a coolant leak behind the motor somewhere. Turned out it was just the heater control valve that had a slight leak and the coolant traveled down the hoses and for whatever reason made the trek all the way to bellhousing area. I have never seen a 1UZ with aforementioned coolant leak.

Barbary

Thanks Slide, I'm putting my money on the thermostat and feeling a lot better and you just doubled down

RXRodger

iTrader: (2)

If it's at the back of the engine, are you sure it's not the connections to the heater core? Those are at the back of the engine and much more likely than a freeze plug.

Barbary

Thanks Rodger, looking more and more like the thermostat, no leaks at the back. Seems engine may have overheated from a bad thermostat
taking it in tomorrow 🫰

PERRYinLA

Very true - that's the leak I have, and I've lived with it for the past several years, since it's a small leak that never got worse, and the fix is no fun - that's a cramped area.
I was told you have to lay cushions/blankets over the engine and then sprawl out over the top to get down there.
But at least the trans stays put.

Barbary

I did a google search and forum search looking for the location of the thermostat on my engine or even a full 1uz engine diagram and came up with only confusing stuff. So can anyone let me know where my thermostat is located on my engine
much thanks

LeX2K

'Stat is right by the ignition coil follow the upper rad hose.

Barbary

LeX2k, Thank you so much

Barbary

Well I've been put off on the thermostat install till next Thursday. From where the stat is located it looks to be a very simple job, but I don't even own a wrench and wouldn't know what to do w it if I did. Started thinking if they do have to pull the motor I might as well swap a 2000 year 1UZ-FE, into it, a refurbished one, if there good ones like that even around. Looked at some places (Ebay) and google saw only as is, nothing rebuilt

The car is still knock me down beautiful to me, and after all these years is exactly the way I want it (including a hardtop), with some modern updates. Not many, Interested in driving, not infotainment.

Starting to sound exciting driving around in a very late year 1UZ-FE maybe w a newer 6 speed auto, up here

Barbary

Hello guys, well it's been a wild "Goosey" chase. It's tough getting care for an SC in small mountain town. Especially when it's the only one, I think, ever been up here.
Anyway, got a new thermostat, water pump, which was the problem, (leak) and a new timing belt installed. Up and running, with some more peace of mind. Case closed
Thanks guys

Bimmerbill

Hey Barbary,
Now that is what I call good news. Now you are ready to roll again with no worries, you can get out there and take some more of your great pictures.
Good luck,
Bill

SC400slide

iTrader: (11)

Great to hear you got it figured out. While on the more costly side of things I'm sure, i'm glad to hear it was as simple as the water pump. Timing belt must have been fairly old for water pump to leak, or it was not installed perfectly when T-belt was done. On my 93 SC400 the P/O had never done the T-belt. I bought it non-running with coolant leak. Water pump, tensioner, and T-belt were all original from 1993. The belt was so bad it literally was in a crumbling state and came off the upper cams like strands of string. Glad you got it figured out!

Barbary

Thanks Slide, Glad you caught the belt before it went all the way.
I did put a new belt and pump when I first got the car, so they've been on there at least fifteen years, probably longer. And they have been hard 15 yrs (lot of deserts, long miles, and mountains). Have kept an eye on the belt along the way and have been told they were in good shape. So the pump failed and was OK putting out the money for a new belt, the whole works. For the peace of mind. Hope they put it on perfectly
I mentioned in my build this is the cars 3rd timing belt and 3rd windshield ...(not sure what that means) 🤞🏻

Barbary

Addendum added
Got the car back w severe miss fires, now it's starting to be never ending.
My poor car, poor me
Got the car to a chain repair shop (wasn't easy) had them double check the timing belt and timing. They diagnosed the miss fire.
The rotor plug wires were shot. Replaced them all and plugs. Wound up with a pretty decent engine overhaul. Drove home everything running good.

I'm exhausted