SRK

I'll second curiousB and state that the battery must NEVER be disconnected with the engine running. Hopefully the alternator has worn brushes and was unable to produce enough current to blow a diode or two when you did that little trick. If not, the alternator will now require a complete overhaul or replacement, rather than a simple brush replacement. If your power steering pump is leaking, or has leaked, the ATF softens the carbon brushes, and that's the root cause of the trouble. In the future check output voltage with a VOM as a means to determine if the alternator is charging.

I would suspect the crankcase vent system, before rings or valve seals. If it is the result of rings, it will be on only one spark plug more than likely. Pulling all of the plugs and keeping them in order may help locate a bad cylinder. If it's all cylinders, then the venting system would be my guess. Even if it is the worst case, that the engine is damaged from overheating or running out of oil, the repair would be to install a good used engine, not rebuild it. Lexus doesn't supply over-size pistons, and I've never heard of anyone needing them anyways.

It's an interference engine. Seven years is the time interval for the change. I did the t-belt on my GS400 at 100k kilometres when it was eight years old, and it needed replacing. No sense driving these cars while worrying about the belt. Peace of mind is worth it.

Buying any car with your last dime expended is not a good idea, and buying a Lexus with your last dime expended is even worse. Save your money and wait until you can afford the car. Otherwise you'll be sitting on your front porch looking at it, rather than driving it. Needs and wants are two different things.

You could do a search. Common problem, but it's not the starter, it's the contacts in the starter solenoid. Two different things, attached together. I'm glad your mechanic is an "engine guy". Just what kind of mechanic isn't? Clothes dryer repairman? Dish washer technician?

Ask them where the chip is on the LS400. I don't think they'll know. Which means they are BS artists, and bad ones at that. 50 horsepower at the rear wheels. I don't think so.

Strange....most of my pals say the exact same phrase to me, quite often in fact......you don't think.....gasp......that I'm opinionated do you????? Oh No!!!!!!

That guy should be shot with a ball of his own !Removed!.

Perfectly safe. Just keep it in park, and apply the parking brake. It's safe to operate the driveline, if precautions are followed, but just the engine - easy.

Well yes it does make sense. You are thinking of trying different width tires, and compensating for that width with varying aspect ratios that will give the same sidewall height as stock. The problem with that is that any handling improvement will be incremental at best. If you are staying with the stock wheel, stay with the stock tire, would be my advice. My 92 LS has 94 wheels on it now. But I calculated the correct tire in the new 16 inch wheel to match the original diameter of the 15 inch tire size. That worked out to 225/55-16, rather than the 225/60-16 originally used on the 93-94 cars. So my sidewall height is a bit reduced, the tires look good, and handle far better than anything the 15's ever had on them. But the improvement over the stock 16 tire....well it is tough to say....I'd like to think the turn in is better.....but's that about it. Hope this helps.

Always change the filter. I use the Toyota ones. Cheap in a 12 pack. All four O2 sensors have different codes associated with them, so your "shop" should be able to tell you which one has failed, and replace just the one. There is no need to change both, or all of them, at the same time.

If you are so concerned with engine sludge why are you waiting a few weeks to do the oil change? Just change the oil, perhaps at shortened intervals - 2k miles perhaps for a couple of changes. I wouldn't use any additive at ALL. Modern engine oils are one of the most intensively researched and blended liquids you can think of, and the dorks who run "seafoam" don't know more than Exxon.....

Your sequence is correct. Nankang tires are terrible. Buddy of mine peeled a few off the front axle of the company semi-tractor he drives, until he told the boss he would NOT drive the truck unless quality NA made tires were installed. Absolute junk tires.

Radials get rotated front to back - no crossover. In other words, don't change the rolling direction once they have taken a set. Lots of tire guys will tell you "modern tires can change direction, it's no problem". No they can't - you'll get a vibration just like an imbalance and it will never go away. If you have to go side to side, then the tires should be dismounted and installed so that the direction does not change, when they are switched to the other side - the left side tire outer side wall becomes the inner on the right.

The LS ride quality is unbeatable. Far better than the GS. Just where it is compared to the BMW you have I don't know. The LS is the big sled, the GS is more like a 5 series BMW. Different character altogether. I think you'll like the LS - and they don't lack power at all. They are so smooth they'll fool you as to just how quick and fast they are.

They are both great cars, but completely different. You'll have to drive them both and make up your own mind. We can't do that for you. I have an early LS and a first year GS400. At this point I'd buy the LS430, but that's just me. When I move on a LS430 it will be for me, and the wife will have the GS and I'll sell her older LS.

Damn observant of you. See post 15 of this thread. If you pay a grand for this job, you're getting ripped. To a properly trained technician, it isn't a big job. Neither is a water pump.

There are reasons for the starter to be there - it's not "dumb". First it allows the exhaust manifolds to be tucked in tighter to the block, to allow easier packaging of the engine in the car. Second, the cats can be placed closer to the exhaust ports to improve efficiency. Third, the starter is not exposed to heat from the cats. Fourth, because the intake manifold is a "ram" type, a large hollow exists in the valley of the block for it. Other manufacturers place the starter in this location - the Northstar V-8 does it as well, for the same reasons. If you had any experience working on Porsche, BMW, or Mercedes you'd think it an elegant solution. I do. We all know that these cars aren't like a '64 Buick. Don't expect servicing them to be like a '64 Buick either.

No need to apologize Marklouis - I enjoyed your post. No foul at all. As much as bugs and large bits look bad on an air filter, it is the fine stuff that plugs them. Years ago I drove a Cummins powered truck in the summer, and noticed a lack of power one day. The air filter was covered in a fine brown powder, like wheat flour almost, from the dirt roads. I knocked it out for a while and removed pounds of the stuff. Perked up the engine right away.

LOL - Very good one!!!

I am always amazed by how conjecture, opinion, anecdotal evidence, self-fulfilling prophecy, blind adherence, rationalization, and dogma can be passed off as science. Of course many people believe there is a grey-bearded guy who lives in the sky. Change your sensors, avoid the Bermuda Triangle, practice safe hiking around sasquatch, and consult the stars for your future. Myself, I trust science. Submitted respectfully, SRK.

Junk Science.....I like that term! That's exactly what this "sensor change" thing is....and when is the last time a temperature gauge sensor ( very similar ) gave spurious readings....more likely it just failed altogether, and on a Dodge, not a Lexus. I smell an urban myth developing. CuriousB and I will squash it yet!

Thanks for stating this. A failed ECU temp sensor will pop a code, and they are easily tested. Specs are provided to ensure that they are within range, but mostly when they fail, they fail completely and the engine goes into limp home mode. As well, the fuel trims are established by the O2 sensors, so even if the sensor went out of range before failure, the O2's would maintain the fuel-air ratio. Consequently the idea that changing the sensor as one would do for a spark plug is a good idea makes no sense to me. If it ain't broke, don't fix it.

The purpose of the O2 sensor is to maintain stoichiometric under all conditions, except wide open throttle, where overrich is used to protect the engine and briefly overheat the cats to clean them. The reason for holding stoichiometric is because at that point the three major pollutants are at their lowest. Leaner and NOx goes up, richer and CO and HC go up. It's the "sweet spot" for emissions in other words. Stratified charge, if it is used, is intended to keep mixture formation away from the cylinder walls and combustion chamber to avoid the cooling they impart, which raises HC. So as the engine is programmed, without any chance of modification, to achieve perfect combustion within it's design limits, there is nothing to do but drive gently. You may experience a "light load ping" with regular fuel, but I highly doubt it. Even if the engine did ping, the low cylinder pressure means it is quite benign, and will never damage anything. I'm glad you understand aircraft engines. I'm a former pilot, and I am a member of the AEHS -devoted to historical aircraft engines. As you know ALL large displacement aircraft engine must now operate on 100LL fuel, which is far less octane than they were designed to operate on. And yet they still fly. Why? Because the pilots do not allow the engine to develop the boost that they used to - lower cylinder pressure saves the day. So no Merlin can produce 1900 plus horsepower today like they did on 130-145 octane fuels - they make 1400 on 100LL and are glad of it. Same with the big Pratts and Wrights. The boys at Reno run huge boosts, and blow the engines apart routinely, because of this. Engines can't read - they don't know what the valve covers say. They just run, and the principles are the same. The wife puts 89 in her LS and it runs perfectly. I put 92 in my GS (94 is available where I live) and I beat the hell out of it. No pinging. Static compression ratios are not the same as dynamic, which constantly change according to throttle opening and rpm, unlike diesels, which nearly achieve the static CR at all times. Whew.

Given that the engine has a management system that is among the best in the world, the only way you can improve mileage is by driving style. And that would mean !Removed!-footing around and using very little throttle. Which would then mean very low cylinder pressures, and that means no need for high octane fuel, which is only advantageous at high cylinder pressures. You would do well to study engine design (aircraft piston engines in particular), physics, and chemistry.