Moonstruck

My neighbor here in Naples FL has a 2015 LS460. Today he asked to use my Toyota minivan to move some stuf. I drove his LS while he had my van. The car is luxurious and extremely nice. For almost having 400 HP I thought it was a little sluggish. I know it is a big car, but I'm just saying. Is it the same V8 as the one in our cars, just with a longest stroke to give the extra 300 cc's?

Coleroad

It's a whole different block, cylinder head. It has direct injection. It uses aluminum magnesium alloy block. This was brought in in 07 to phase out the 4.3. Like all direct injection engines it probably has a lot of carbon build up on the back of the intake valves. With no fuel to keep them clean they get a very thick build up of carbon that needs to be cleaned. So if it's got 50 or more thousand miles it's probably down on power from this.

Moonstruck

OK, that clears that up for me. Not sure what the mileage is on his car, but I'll check with him in the morning.

Coleroad

Here is a video so you can see what I'm talking about with direct injection

Bgw70

Thanks for the education Cole!
I was curious, what is the advantage of direct injection?
Direct injection seems to have more negatives than positives!

Coleroad

T
Better fuel metering, better atomization of the the fuel. More power, better fuel economy. Better control over how the fuel burns.

Down side, intake carbon build up. A high pressure high volume fuel pump that seem to have shorter service life.

It's all about more power from less fuel and weight. That's also the reason for the run on turbochargers.

texsexlex

iTrader: (3)

...so I'm thinking about purchasing a 460 later in the year, what's the best way to clean or help reduce buildup that might be already in the intake

Bgw70

Cole posted a YouTube video and the guy explains how you remove the carbon buildup.

Coleroad

The fastest option, but special equipment needed

Coleroad

You can clean with picks, brushes, soaking in cleaner. Effective but labor intensive. Not the best video but you get the idea.

riknchar

I own a 2008 LS600hL, in addition to my 2002 SC430, and I'm an avid follower of both the SC and LS forums. I can say from my experience with the LS 460, and from reading virtually every post on the LS460 forum, that carbon build up due to Direct Injection is not common. If you do a search for Carbon Build Up on the LS460 forum, you pretty much come up empty. Some people do complain of the somewhat diesel-like noise that comes along with the Direct Injection, but no one complains of carbon build up.

Coleroad

Is the 4.6 using the duel injection. Mean a small fuel injectors in the intake along with the direct injectors? So that some fuel is being sprayed on the back of the valves.

Moonstruck

As stated in my original post, I did notice some sluggishness in the LS460 compared to my Sc430. I do have to say that for a car with almost 100 more HP than my SC I also was disappointed in the performance. I would not believe that it could be carbon buildup as the car had just turned 20,000 miles. Again I do realize that it is a big car and that it is intended for a different buyer than the SC was. The 8 speed transmission does seem to be amazing.

riknchar

That's right, Coleroad, the LS460 uses a combination of Direct and Port injection. It's an amazingly effective and reliable fuel delivery system, with the only reported problem (by some) being an audible "diesel-like" clicking sound from the Direct injectors. I haven't experienced that issue, and haven't taken any specific steps to clean my fuel injectors (other than running good Premium gas).