I've owned the 95' SC400 for a week now and have a few questions for those DIYers. Searched with no luck.

I'm a huge fan of Royal Purple and run it as engine oil, trans fluid and gear oil in my 4Runner and Subaru Foreste XT.

Book says 5-30 for oil "new". Still run the same weight at 135k?

What about trans fluid type? A few more to select from than there was in 1995!

Gear oil good with 80-90w?

My temp gauge seems to stay very low even with the engine warm. Heat is blowing warm, not HOT. 30 min of driving and it still only reaches the first notch on the gauge. And I have fun on the way to work every morning. It is 30deg on the way to work bet it's the same on the way home when it's 70. Thermostat? Temp sensor?

Thanks for the newb help!

 

RP in the engine would be fine, 5-30 unless you are seeing blue smoke.

In the trans, NO to RP. Use the Toyota T-4 ATF. I speak from experience, you do NOT want to deviate.

RP in the diff should be fine.

Likely thermostat is stuck. Replace that and coolant while you are at it.

 

+1
10char

 

I used mobil 1 in the tranny, nothing bad has happened so far, been about 7000 miles.
Is there a reason not to deviate on our cars? I don't see why it'd be a big deal. Mine is a stick though.

+1 on the thermostat and coolant flush. The stock thermostat sticks closed when it's broken on the 92, but I imagine that the 96's probably have the newer thermostats that stick open when they break. And it takes about 30-40 minutes for the engine to heat up without a thermostat or with it stuck open, so it definitely sounds like your thermostat is stuck open.

+1 on the oil advice as well. 5-30 is fine.

 

T-stat was stuck open. Replaced it and got to normal op temp finally. T-stat and o-ring from dealer at $36. But during the replacement I snapped the outlet off the radiator that goes to the reservoir. Barely touched it! Had to fish the plastic pipe end (which was corroded really bad, very soft) out of the hose. JB-Welded it back in place so that I could drive it for a couple days while I waited on the radiator to come in. Once again JB-Weld has come through for me for a quick fix.

I did a little research and ended up with a Spectra B1306 rad for $186. I think the rad was slightly clogged as well. I had to add about a qt more water to it on top of what I recovered. No more bubbling noise from the heater core. Looking forward to the improved mpg's thanks to it running at the correct operating temp rather than under the second mark, whatever that is. Always smelled slightly rich.

Oil changed with RP 5-30 and Wix filter. Running that setup in all my cars for past 6yrs.

So, trans fluid needs to be the T-IV from Toyota? Similar with my Forester. It works great for a day or so but then you feel the different shifts that are just...off.

I'm trying to keep this car on a budget, tight one! It's just a daily driver. I love the way that it drives, and yes, I corner it pretty hard every day on the track-like road I take to work every day. Only thing that bugs me right now about it is the wheel/tire setup. The thread on that is awesome! I'm only gonna swap out if the right deal comes by, but they will be wrapped in Nitto Invo's fosho! I'd love to take it to Leguna Seca this summer.