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What Is The Highest Rpm You Have Had Your Ls400 ?


90LS400Lexus

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Although I don't routinely run my Lexus to redline, I have on many occasions. The first time I floored it I was getting onto an Interstate. Well, it surprized me! the engine downshifted into what I believe to be first gear and went directly to 6200 before kicking into second. I held it until I was up to about 90. As promised by others, the Lexus has a sweet sounding engine at high RPMs. Set me back in the seat. Since I didn't want to feed the bears, I let off. Since then I guess I haven't been able to resist.

I also have heard about breaking engines in at high RPM's. Since my engine only has 133000 miles on it I figure that is what I'm doing. All I can say is make sure there aren't any cops around.

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That's not true at all. Break-in periods are required in every engine that I have read about or have any experience with. In fact, with modern designs, they're setting up engines so that break-in will be even more important than it used to be. They let the final machining be done by the engine itself during its break-in period because the engine itself is more precise than the machining equipment used to make the engine parts, and it's signifigantly cheaper.

Look in your owner's manual, I bet that it has info about engine break-in in it. I know that mine does.

And for modern advanced engines like the BMW E46 M3's, break-in is crucial to the life (and survival) of the engine.

And deposits can form with any oils, even synthetics. And not every lexus has synthetic oil in it. And the technology for Dino oil hasn't changed that much in the last few years.

And I wouldn't suggest taking a lexus that hasn't been over 3k rpm's before and starting it up cold, and immediately revving it up and holding it at the rev-limiter all day long. If anybody'd like to try, be my guest.

And the fact that your eyes can't tell a crankshaft spinning at 3k from a crankshaft spinning at 6k doesn't mean that there's no difference.

Just because you drive a modern car (like a lexus) with a modern engine (like your lexus's) doesn't mean that your engine is immune to abuse.

Your concerns about your engines are warranted.

Level8Drummer

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They let the final machining be done by the engine itself during its break-in period because the engine itself is more precise than the machining equipment used to make the engine parts, and it's signifigantly cheaper.

And for modern advanced engines like the BMW E46 M3's, break-in is crucial to the life (and survival) of the engine.

And I wouldn't suggest taking a lexus that hasn't been over 3k rpm's before and starting it up cold, and immediately revving it up and holding it at the rev-limiter all day

I don't know where you got the idea that modern cars need MORE break-in. Ever rebuilt a Ford flathead? The Lexus engine is machined to closer tolerances.....and doesn't need a break-in.

As to the BMW M3 engine, there is a nasty TSB on them for "machining particles left in the engine at assembly" requiring replacement of the connecting rod bearings. And the BMW V-8 of the early 90's is noted for excessive cylinder wall wear and the company spent a ton of money on warranty claims. All the break-in in the world won't fix those problems. I owned a BMW once. Never again.

And I don't recall advising revving an engine from cold.

List the engines you have rebuilt and warranteed to customers. Here's mine:

Lotus

BMW

Porsche

Mercedes

Volvo

Ford

Chevrolet

MG

Buick

Alfa Romeo

and others I forget.

I advised the folks to "take it easy" for a few miles, and who knows if they did. Didn't matter as none blew up.

There is no replacement for good machine work, and if you have that, you don't need a break-in.

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No I haven't rebuilt an engine, but I know how to read a book. And I don't think that the engine designers at BMW spend that much time with wrenches in their hands either.

Actually, both of your BMW references are out of place. That service bulletin and the engines that BMW has replaced had nothing to do with the way that the engine parts were machined, it was due to customers not properly breaking-in their engines, and then taking the RPM's up before the engine had time to reach operating temperature.

And as for the M60 (which is the V-8 engine that you're referring to, and the one in my car), neither break-in or machining had anything to do with those failures. They were due to the sulfur in US gasolines bonding with the nickel in the cylinder walls, and eroding them away. Eventually, the engines would lose compression, and not run. But BMW replaced those engines for their customers (including myself) with brand new Alusil engines.

It's a shame that you don't have a BMW anymore. They're great cars, and they make the best engines in the world. They also make the best handling 4-door sedans on the market. They win awards for their engines every year. I didn't know that ls400's had timing belts until I came to research it for my father. BMW switched to timing chains in the early 90's.

You didn't advise revving an engine from the cold, but you did say that you could keep the engine at 6k rpm's all day long. I don't think that your engines could stand up to that. I don't think that most BMW engines could either.

I'm not going to turn this into a *BLEEP*ing match, I just hate to see people be ill-advised about how to take care of their cars.

And maybe you're the kind of guy who rebuilds engines and doesn't tell the customer how to take care of them, and thereby gets more business with engine problems a few years down the road. Back when I was younger the guys who worked on my brakes never told me about breaking-in my pads and rotors either.

There are old sayings like, the doctor's kids are the sickest kids on the street. And nobody takes worse care of their car than a mechanic. You know why? Because a mechanic can cheaply fix his car when he breaks it. The average guy, like me or some of the guys on these forums can't. We have to take the car to somebody like you. And it's just not right for them to be ill-advised.

Level8Drummer

PS. Break-in your engines guys, and follow maintenance schedules, and your Lexus's will last a long time. If Lexus (or your owner's manual) tells you one thing, and your mechanic tells you another, listen to Lexus. They already made their money when your bought their car.

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Sorry. I did not mean for this topic I started to cause problems.

Actually I think it is a great topic, and went a long way to promote discussion. No need to apologize in my mind 90LS400Lexus.

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