Mk4 LS400 won't rev past 5k

[Dale_V]

8 minutes ago, cornershop said:

Nothing wrong with red lining your engine, I find engines that have been regularly exercised to the red line more performant than those mollycoddled at barely tickover speeds. Stereotyping somewhat but the age groups that own Ls400s are much less likely to do this!

I’ve had 3 or 4 cars on a chassis Dyno, they all feel much smoother and more responsive to drive after a hitting the Rev limiter a few times during the test.

Exactly this. Just tootling around will do your engine, especially the fuel and exhaust system no good. I once bought a Toyota mr2 that felt strangled, after a few weeks with me it was producing good power and behaving how it should. 

And let's be completely honest, the ls400 is adequate in its power, but by no means whatsoever powerful, so giving them a good kicking now and again will not only do it good but it's very unlikely you can get in trouble in doing so. The talk of without due care etc is bonkers. There's a time and a place to perform such antics, basically using common sense will give a good indication when you do so.. Although common sense seems to be getting rarer by the year.

[cornershop]

Aka - The Italian Tune-up

[JohnDavis]

Touching the rev limit sometimes is OK, indeed as others have said beneficial, with such a strong engine, but cruising at 150 for a long time would overstress the driver, never mind the engine! Just make sure your cambelt is well in date before you do it. 

At one place on my drive home from work I turn from a quiet side road onto a wide and well kept main road that's often empty (It's Norfolk, after all) and using the selector I can get 5500 in one and two and 4000 (low eighties) in three - 60 in about 7 seconds - then there's a railway crossing and 40 limit so it's brakes on! Brightens up my journey every time.

[Daveyboy20]

3 hours ago, Dale_V said:

Exactly this. Just tootling around will do your engine, especially the fuel and exhaust system no good. I once bought a Toyota mr2 that felt strangled, after a few weeks with me it was producing good power and behaving how it should. 

And let's be completely honest, the ls400 is adequate in its power, but by no means whatsoever powerful, so giving them a good kicking now and again will not only do it good but it's very unlikely you can get in trouble in doing so. The talk of without due care etc is bonkers. There's a time and a place to perform such antics, basically using common sense will give a good indication when you do so.. Although common sense seems to be getting rarer by the year.

Although I'd argue that nigh-on 300hp is powerful. Certainly feels powerful in my 13.9 second Capri!

[dendonc]

22 hours ago, Dale_V said:

so giving them a good kicking now and again will not only do it good but it's very unlikely you can get in trouble in doing so

OK, but if thats so then its got to be more detailed than ''now & then'', it's that part that confuses me a lot, especially these days with almost all parts of all cites imposing this ludacris 20 mph limit & lots, maybe the vast majority of cars here in London never, ever go outside London at all. Some, almost certainly a small minority, might go outside the city once or twice a year for short breaks, so what do you think the problems are this kind of ownership/driving is causing? Bye the way, the notion of giving cars what is now being called red lining goes back at least as as long ago as 1960's, but no one then ever said why it did cars good, so whats theory behind it?

Looked at from another angle, London based cars, stuck with a 20 mph limit, probably do far, far less mileage per annum that those in rural areas, that tends to indicate there would be far more wear on parts of rural use based than london based cars with very, very low mileages

[Mr Ponkerson]

^ I always thought it was initial low temp running that increased wear rather than out and out mileage - once everything is up to temp the wear is much reduced, it's repeatedly using the vehicle below operating temp that increases wear (hence town driving not being seen as ideal compared to motorway)

[cornershop]

as above - I’d much buy rather a high mileage motorway driven car than a London based car.

[JohnDavis]

The rationale behind giving the car some stick is that the increased temperatures and airflows blow excess carbon out of the combustion chambers ( do it in the dark with a car that's been lazy and you'll see the sparks from the exhaust), impurities and moisture in the engine oil are boiled away, and increased oil flow and pressure cleans out oilways. It also runs some sensors and actuators to their upper limits, keeping them free

That said, not all engine designs can take it, so it is not necessarily a good option on older cars, or those that are not well maintained.  

[dendonc]

26 minutes ago, JohnDavis said:

The rationale behind giving the car some stick is that the increased temperatures and airflows blow excess carbon out of the combustion chambers ( do it in the dark with a car that's been lazy and you'll see the sparks from the exhaust), impurities and moisture in the engine oil are boiled away, and increased oil flow and pressure cleans out oilways. It also runs some sensors and actuators to their upper limits, keeping them free

Yes that I understand, thanks.