monarch

I'm not saying I have a "pristine, carbon-less 400K mile Toyota engine". I'm just saying that the carbon that exists in my engine hasn't been causing pinging or preignition or a decline in fuel economy, power, compression, drivability, spark plug cleanliness etc. As far as "proof" is concerned, well most of us know that if an engine is consuming excess gasoline it's also producing excess hydrocarbon emissions which in turn causes the EGR valve and pipes to become clogged with carbon and decreases the life of the catalytic converter. Now since my 468,000 mile engine still has it's factory original EGR valve and catalytic converter and still passes California smog testing, I believe that proves these components are still in good operating condition and in turn proves carbon deposits never caused my engine to burn excess gasoline.

The engineers say the additives "can be harmful to the fuel system and engine" but don't say specifically what the consequences could be. I'm just pointing out that the Lexus owners who disobey the engineers and go ahead and use gas & oil additives and / or advise others to do so don't know what the specific consequences could be either.

We still have not resolved the issue of whether or not the '95-'97 Lexus V8 is a "Non - Interference" or an "Interference" engine ? I'm hoping for more professional input about whether or not the pistons and valves will collide and be damaged if the timing belt breaks on the '95-'97 Lexus V8.

I bought my two identical trucks brand new, one got driven 468,000 miles, the other sits mostly in the garage, but serves as a baseline about how well a near new truck can perform. I've monitored fuel economy, power compression and emissions of both trucks since they were new. The 468,000 mile truck still idles as smooth as the low mileage truck and power and fuel economy continue to be like new, despite never having been treated with gasoline or oil additives. To get to my house I have to climb a long 7% freeway grade nearly every day which requires near full throttle to maintain speed up the hill (if I use 5th gear). If my power was down, my speed up that hill would be down, but it hasn't gone down.

But TOYS and SK have not explained why the factory engineers warn owners not to use gasoline and oil additives. TOYS and SK havn't explained the specific short or long term consequences that can happen to an engine following their use. Likewise there are owners on the forum who disregard the warnings of the Toyota engineers and advocate extending oil changes when using synthetic oil and who further say there are no consequences if an owner switches back and forth between synthetic and conventional oil. But these same owners can't tell you why the Toyota engineers warn against these practices.

In addition to my 1992 Toyota pickup with 468,000 miles, I have a 1993 Toyota pickup with the same engine, but only 74,000 miles. I bought both vehicles brand new. So the low mileage '93 engine gives me a point of reference to evaluate any change in '92 engine in regards to power, fuel economy, emissions, compression, etc.

You'll notice your fuel economy is up 1-2 MPG too and therefore the new oxygen sensors will pay for themselves within 25,000 miles.

Toysrme, I don't have accelerated spark plug wear problems on my 468,000 mile and 248,000 mile Toyota engines that have never been treated with gasoline or oil additives. I don't have lowered engine compression, fuel economy, power or increased emissions so I don't have valve sealing problems. I don't have carbon build-up on my intake or exhaust valves sufficient to cause a severe decrease in the flow past them because my power, fuel economy and exhaust emissions are still excellent. I don't have carbon buildup on the top of my pistons sufficient to cause combustion pinging or preignition. I don't have carbon build-up on my EGR valve sufficient to cause a decrease in power, fuel economy or failing scores on the California nitrogen oxide smog test. I think a very important reason for NOT cleaning the carbon out of an engine is that many of the world top automakers (Toyota / Nissan / Honda /BMW) urge owners NOT to use gasoline or oil additives http://www.saber.net/~monarch/nis.jpg Reasonably, the graduate degreed engineers of these automakers must know there are consequences associated with the use of these additive products. Reasonably, these automakers would also market there own brands of gasoline and oil additives if they thought there was a legitimate need and if there were no negative consequences.

I agree with Kennyr - just install new Lexus pads and pray the Indie is competent enough to install the pad hardware correctly, including using the correct grease on the correct spots if specified in the factory service manual. If brakes squeal, something is usually wrong with the pad mounting hardware / installation. The Lexus factory technician training service manual advises techs to replace rotors only if the runout exceeds a certain limit. In other words, don't replace or resurface rotors unless there is an excessive amount of pulsation felt when braking. Lexus rotors may also wear too thin, but normally not until the 3rd pad change.

My experience has been that Dynamat Xtreme type products are vibration dampers, not sound absorbers or sound barriers. Since a Lexus already is already extensively vibration damped, products like Dynamat Xtreme do not cut down much on interior noise levels. I believe the most prominent noise in a Toyota/Lexus is road noise and traffic noise it needs to be attacked with sound absorbing materials like fiberglass, 3M thinsulate, jute padding or accoustical foam and sound barrier materials like loaded vinyl mats or asphalt impregnated jute padding. You either have to spend $500+ on these types of products from commercial sources or visit auto wrecking yards and take them out of existing luxury cars and passenger vans.

Can you tell me why should I be concerned? Is my '92 22R-E engine power down after 468,000 miles? Answer: NO. Is my fuel economy down? Answer: NO. Is my idle smoothness down? Answer: NO. Is my engine compression down? Answer: NO. Does my engine ping? Answer: NO. Do I still pass the tough bi-annual California smog test with lots of room to spare? Answer: YES. So I don't understand why I should be concerned about the cosmetic condition of my combustion chambers or intake manifold. Sure I imagine there is carbon in there and it's been there for the last 100,000, 200,000, 300,000 and 400,000+ miles. And it'll be there when I top 500,000 and 600,000 miles too. Same situation with my carbureted 1989 Corolla 4A-F motor with 248,000 miles. No additives ever used and no noticable decline in power, fuel economy, idle smoothness, still passes smog, etc. So I don't understand what specifically I am missing by not engaging in "blowing out the carbon" rituals with Marvel Mystery Oil, Seafoam, Chemtool, and similar products.

I havn't used Seafoam or additives of any kind for 468,000 miles. Instead I prevent fuel injector or intake valve deposit problems from ever developing by using a top tier, high detergent premium gasoline like Chevron or Shell. About every 30,000 miles I also scrub the throttle plate clean manually using a toothbrush, throttle plate cleaner and some old rags.

Your '94 ES came from the factory filled with Toyota long life antifreeze (red in color) and distilled water. To find out what happens when early 1990's ES owners have used aftermarket coolant for a long time, just search the ES forum using "head gasket", "overheating", "new radiator" as your search words. Toyota has been aware of what happens too and that's likely why, beginning with the 2003 owners manuals, Toyota has strongly urged owners to use the factory red (or pink) antifreezes.

The Lexus factory service manual recommends draining the coolant through all three drain plugs (the one at the bottom of the radiator and the two at the bottom right and bottom left of the engine block), then refilling the cooling system with a 50/50 mixture of Toyota Long Life Antifreeze (red in color) and distilled water. The problem with the heater hose method ( if used instead of removing the engine block drain plugs) is that it leaves the engine block full of tap water which, over time, leads to corrosion of the aluminum cooling passages and pipes in the engine and leads to mineral deposits inside the radiator. These problems in turn can lead to cylinder head gasket failure and engine overheating. The Toyota red antifreeze is a concentrate you dilute 50/50 with distilled water. The Toyota pink antifreeze is ready-to-use as is. Therefore the red antifreeze is less expensive to use even if it costs more per gallon.

According to Consumer Reports owner surveys, the '04 RX330 had some brake system problems that were completely resolved by '05 http://i5.photobucket.com/albums/y189/mastertech/cr.jpg The overall reliability record of the '04 RX330 is better than average.

There are two types of genuine Toyota oil filters for the Lexus V8's. The part #90915-20004 filter has a soft, spongelike synthetic resin filter element. If this is the filter your friend opened up then he mistakenly assumed the filter element was made of paper. The other genuine Toyota oil filter for the Lexus V8's is part# 90915-YZZD1. This filter has a tough paper filter element. If you open one a used 90915-YZZD1 yourself you'll see how tough the filter element really is. Independent auto repair shops can't buy genuine Toyota oil and air filters or other Toyota parts any cheaper than you can, but they can get deep discounts of NAPA and other aftermarket brands. For this profitability related reason, independent auto repair shops* generally only use aftermarket parts, filters and fluids and they bad mouth OEM parts, filters and fluids. *an exception is Toyota / Lexus specialty repair shops which often use genuine Toyota parts and filters. Oops, I forget the part# for the Lexus V8's is actually 90915-YZZD3. The D1 filter is for the Lexus V6's

But Blake has a '95 model which had some updated engine features, including (presumably) improved oiling to the particular valve lifters that tended to suffer wear on the first generation LS400 motor. I know for sure from first hand experience and reading other posts that the '90 & '91 models have this wear problem and it can show up as a ticking noise at warm idle in as little as 70,000 miles. Whether or not the '92-'94 models also have the problem too I can't say for sure. In any case, if your '94 V8 doesn't have any ticking noise at warm idle then none of your valve clearances are likely badly loose. Checking the 32 clearances is actually quite easy once you get the valve covers off. Adjusting the clearances (if needed) is more complicated.

Lexus.com FAQ: Use of Synthetic Engine Oil Question:Can I use synthetic engine oil in my Lexus vehicle during its break-in period? Corporate Lexus's Answer: "Synthetic oil can be used at the first scheduled oil change. Even if synthetic oil is used, we do not recommend longer oil change intervals. Once synthetic oil is used, it is best not to switch back to petroleum-based oil." Valvoline.com FAQ: "How often should you change your oil? The answer is simple—it depends. The general guideline for changing motor oil is every three months or 3,000 miles—whichever comes first. Although some car manufacturers and motor oils claim that maintenance intervals may be extended, there are still many benefits to changing your oil every 3,000 miles: 1. the emission of dangerous pollutants like hydrocarbons, carbon monoxide and nitrogen oxide increase as oil ages. In other words, old oil increases air pollution. 2. cars that have been subjected to extended drain intervals may continue to emit higher levels of pollution even after they adopt a more conservative maintenance schedule. 3. Fuel consumption also increases as oil gets old, and vehicles may continue to burn higher quantities of fuel even after the oil is changed." Camlex, as you know, the purpose of changing your oxygen sensor recently was to optimize engine power, fuel economy and reduce the concentration of hydrocarbons, carbon monoxide and nitrogen oxide in your exhaust stream, thereby prolonging the life of your expensive emission control components. Extending oil change intervals (even when using synthetic oil) as the Valvoline website pointed out, has the same self defeating consequences as extending oxygen sensor replacement intervals and tune up intervals. So it's no surprize to me corporate Toyota / Lexus is against extending oil changes when using synthetic oil. There are lots of specialty lube salesmen, oil analysis salesmen on a popular private motor oil website that favor extended oil changes (to justify the $7 per quart cost of their specialty oils). They always say: "get your oil tested (oil analyzed) - that way you'll know for sure whether or not its safe to extend changes up to 10-15,000 miles" . What they don't ask you to test is your fuel economy and tailpipe emissions because if you did you'd find out there are self defeating consequences of extending oil changes.

In the late 1970's, before there were government mandated fuel economy standards, Toyota owners manuals recommended 20W-40 and 20W-50 oils for all engines and all temperatures above 10 degrees F http://i5.photobucket.com/albums/y189/mastertech/78.jpg A good way to find out if it's OK to use 20W-40 and 20W-50 oils in a 1UZ-FE Lexus V8 is to consult the owners manuals of 1UZ-FE Lexus's that were sold overseas in countries like Saudi Arabia. The owners manuals of Toyotas sold in tropical climates in other countries of the world typically permit the use of thicker oils. The valvetrain of the first generation Lexus V8 is quiet and does not tick unless the clearances on some of the 32 valves are looser than factory specs. Looser than spec clearances cause a decrease in engine power and fuel economy and an increase in valvetrain wear and exhaust emissions which in turn reduces the life expectancy of some pricey emission system components.

Congrats Threadcutter, for sticking to your guns on this issue. You were right, as was mehullica, the Lexus dealer tech http://i5.photobucket.com/albums/y189/mastertech/tb.jpg

Read this thread to learn how independent car repair shops may sabotage Toyota / Lexus brake systems: http://us.lexusownersclub.com/forums/index...topic=27176&hl= No owner should reasonably expect factory original brake performance from a factory system that has altered For $10 you can download a factory repair manual at http://techinfo.toyota.com/ to learn how the brake hardware should be installed and the recommended brake bleeding sequence. Use factory pads, factory hardware and factory brake fluid http://i5.photobucket.com/albums/y189/mastertech/rxbf.jpg if you want factory original brake performance.

If your LS400 is a first generation engine ('90-'94) then yes you should worry because the ticking noise likely means that at least one and probably 3-4 of your 32 valves are badly out of adjustment (clearances way too loose, degrading engine power and fuel economy and increasing emissions). A temporary fix is to install new valve adjusting shims to bring the clearances back within specs. However, a lasting solution requires replacement of the damaged valve lifters that hold the shims, which in turn requires camshaft removal (and adds some labor time and cost to the procedure). mehullica, the lexus dealer tech, previously explained the lifter damage problem this way: "The last intake lifter on the driver's side head, near the firewall is also notorious to go bad due to poor oiling in that area. The lifter that hold the shim becomes damaged over time on the #7 intake side. The steel insert that pushes on the intake valve gets pressed towards the shim. This will cause the lifter to sag lower on the valve increasing clearance." The '95 on up V8 models don't appear to have this lifter damage problem over time on some valves as evidenced by the fact that the valve clearances on blake's '95 LS400 motor were still all within specs after 250,000 + miles.

Threadcutter said the following about his '95 LS400 engine: "I have a couple of bent intake valves from # 1 Cylinder to prove [the '95 engine is interference]." And mehullica, the highly experienced Lexus dealer tech who has performed hundreds of timing belt replacement jobs and owns his own LS400 told us "1995 on up is interference".

I have found the answer to fustrations like you experienced is prevention. Use only the highest quality six point sockets and six point box wrenches available - like S&K brand and others. That way you won't round any bolt heads off (although rarely you may break them off) Expensive, yes, but the savings in fustration is worth it IMHO. The other answer is to have patience and use the best bolt penetrating fluids available like Kroil and Toyota High Performance Penetrating Lube a day or two ahead of time. These penetrants help prevent the bolt heads from breaking off and help prevent thread stripping.

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