kevin4747

1990 LS400- Do you have any experience with the exhaust on your UZ V8? I need two new cats, the pair next to the exhaust manifolds, and I'd rather go aftermarket to save money. My Lexus dealer says Florida is the one state where it's legal to not have catalytics, can I get straight pipes or will this throw off the engine management or EGR or mufflers?

Any of you familiar with aftermarket exhausts on the UZ V8? My Lexus dealer says Florida is the one state where it's legal to not have catalytics, and I'd like to get a straight pipe system, no matter the loudness, but will it throw off the engine management or the EGR? My car's a 92 SC400.

Anyone ever have luck w/ aftermarket exhausts on the UZ V8? I need two new cats at $2,000 each, but I'd rather put on a less restrictive exhaust, and the Lexus dealer even says Florida is the one state where it's legal to get away without any cats... would really like to get straight pipes no matter the loudness, and would that also help power and mileage? But will it throw off the engine management or the EGR? My car's a 92 SC400.

I'm sure I need to get new catalytic converters for my '92 SC400 so I'm bringing it to the dealer in a week, so can anyone with experience tell me what price I'm looking at? And on a schematic I have it looks like there are 3 converters, do all 3 have to be changed at once and do other parts need to go in also? All my symptoms point to simply a clogged exhaust from a bad cat. Thanks for any advice.

I've had a '92 SC400 with 90K miles for about 6 months now, but I'd stay away from SCs unless you have a few thousand dollars saved for repairs within the first year, or know a good mechanic outside of a Lexus dealer who will do good work. They are moderately reliable, but with the age these cars are getting to parts are going to fail and Lexus parts are very pricey. If you do have your heart set on one it is worth it if you find a good example and can afford to get warrantied parts and labor at a Lexus dealership. I'd recommend looking at GSs or ISs after year 2000, and you'll probably get a more reliable example and a rear-drive Lexus.

Got a brand new radiator and thermostat at the dealership, w/labor and coolant flush/refill it was $1280, they said the old radiator wasn't circulating correctly. Expensive, but worth it since it's all warrantied for a year. Next, I need to find an ECM. The service rep said I could probably find a used one online for about a hundred bucks, and he'll install it for free, any suggestions? Also, anyone know of a good school to go to in order to become a Lexus technician?

Just found out all I need is a new battery. Surprised but relieved, I guess the car can still get electricity from a low battery, but not have the juice to crank the motor? You were right jzz30... cool cars, I had a 94 ES300 that got to 200k easily, now I got this 92 SC400, want to keep it forever, can't say enough about this car. Waiting for diagnosis about Check Engine light and engine overheat/no HVAC heat, see if I can provide some insight about maintaining our cars.

Thanks a lot for the help, got the car towed to dealership and have to wait a few days to get diagnosis, it's gotta be the starter b/c the car has electricity (headlights and guages work), right? Well I was planning to get the car checked out at Lexus anyway, keep you posted

Just go for a Certified Pre-Owned if you can afford it, then you're guaranteed. I've seen Lexuses as old as 2005s w/ CPO warranties, so if you're willing to get a more recent year it should be easy, but I highly reccomend the warranty because the Lexus V8 is actually considerably trouble prone, a dissapointment as I've researched it for years hearing it was bulletproof, and then I finally buy an SC400 (pretty much the same engine), only to find out that it's very common to have trouble with many of the engine's accessory parts, but at least the engine itself is solid,short story, do whatever you can to get that guaranteed warranty.

When I turn the ignition I get the clicking sound and nothing else, car is in great shape with only 94K miles, battery is three yrs old, perfect condition, clean leads, starter and battery have always been perfect, starting right up within a second or two, can't tell from forums what the bad part is, appreciate getting some advice

Search the website for this, same thing has been occurring with my SC400, only I have to deal with the engine overheating as well. Search for 'heater blowing cold air; heater control valve; cooolant; thermostat'- there are many threads as it seems the V8 has a common issue with the entire coolant system. If this is your only issue, hopefully you're just low on coolant or air got into the system, and with the heater core (the heat element of the HVAC system) being at a high point in the loop, it doesn't get hot coolant flowing through, but I can't say for sure the exact way to top off coolant or bleed out air, b/c I'm not a firsthand expert, and I've found about a dozen different opinions on how to work on the coolant system. Hopefully this helps and you could just pay a mechanic an hr of labor to top off fluids correctly without needing new parts. Other than that it seems like there can be issues with the coolant resorvoir (leaking and/or not maintaining pressure), leaks in the radiator or associated plumbing, bad thermostat, or a faulty valve where heated coolant enters the HVAC system. I can tell you if you're determined to top off the coolant level, only take the cap off after engine has cooled, and get the pink Toyota coolant, which seems like it should already be mixed to the proper 50% coolant/50% distilled water solution, and I found a procedure that sounds straightforward to bleed air out where you start the engine,loosen the thermostat (but the forum doesn't show you how to do this) and take the cap off the coolant resorvoir, gas the engine to about 2500rpm, and fill resorvoir with coolant to proper level (though I can't find instructions on what the right level is), and the air will bleed out as you do this for about 3 minutes, stop the engine and when it is cooled top off coolant again, (but I can't find exact instructions- when do you close the thermostat?, and it sounds like there is a gasket in place to seal the thermostat correctly). Sorry if I can't help, but please, someone give us some definitive and detailed advice on how to maintain the coolant- after all isn't the best insurance for a car to keep its fluids topped off?

Is it dangerous to add some coolant/distilled water to resorvoir in order to make it a few days til my appointment at the dealership. A member claiming to be a Lexus technician said this could destroy the UZ V8 as it has to be done as part of a lengthy process. I know to get the Toyota red/pink coolant and distilled water, any advice would be helpful.

I bought an immaculate 92 SC400 with 94K miles, but I'm trying to figure out how to handle bringing the car to Lexus to address a brief and strange overheat. I started to use heat in December, temp gauge went past normal, then heat kicked in and gauge dropped right back to level, a helpful member said possibly a bad thermostat or low coolant, reccomends pressure test to look for leaks, which I'm going to do at the dealership, but the strange thing is at the 90K service with the new timing belt, it didn't get a new water pump. I've been reading forums for a couple hrs a day and it seems like a cardinal rule that you always do timing belt and water pump together. I know the previous owner would not have skimped on any repair because he elected to have all reccomended maintenance done right away at the Lexus dealership. So I'm trying to figure out whether I'll be getting ripped off if they say the overheating issue needs to be fixed with a new water pump, and therefore a new timing belt, even though the previous owner paid for it as part of $2500 worth of routine maintenance less than a year ago.

Thanks a ton. Keep you posted on how I resolve the issue, bringing it to Lexus soon, as I can't find any leaks, coolant level is fine, fan works, love this car and want to keep it perfect.

Look for the forum in the SC club about heater problems, seems like this happens alot, caused by a bad vacuum valve not drawing engine coolant into the heater core for the HVAC. And isn't it annoying with automatic climate control turning on AC when you want defrost? Manufacterers keep saying the AC will dehumidify the air, but in practicality plain hot air works perfect.

Want to see if I can get advice, it would be appreciated. I have a similar problem in that my heater (92 SC400) blows cold air, but the big concern is the temp gauge rises past level, but then the heat will start and the temp needle will drop right back to normal. This just happened today with my first use of the heat this winter. The gauge reading is alarming, but this SC has been perfectly maintained throughout its life, and has been fine in Florida summers. Going to check coolant level when car is cooled down, but what other parts should I look at?