Under-powered Sc430?

[SteveAvery]

Here is a mystery.

I bought a red & white Sep 2006 SC430 with 28,000 miles to replace my black & tan Sep 2007 SC430 with 56,000 miles (which is now for sale).

The black 2007 car with double the mileage is noticeably quicker in acceleration than the red 2006 car with half the mileage.

This is so when comparing the two with the ECT off or on.

I thought that the SC430 engine and transmission were identical in these two cars.

What could be the explanation for this phenomenon?

[Connoisseur]

Basic I know but with the V8 engine first I'd be checking/swapping out the plugs as a new set made considerable difference to me.

[SteveAvery]

Good idea, Michael.

I bought the red SC430 from Lexus, Cheltenham, who had just given the car an 80,000-mile service because it was 8 years old. It has also had a service every year, despite the low mileage.

Do you think that the plugs would have been changed recently or not, in one of these services? There is no way that I can find this out from Lexus, Cheltenham.

[Connoisseur]

Most likely not changed - iirc plugs schedule is for change at 90k+ so the car may be on its originals. In the States many owners swap them after 30 to 60k miles. If changing then imo v. important to fit NGK iridium plugs (OEM).

M

[SteveAvery]

Thank you very much indeed for your advice. I'll act on it imly.

[Spacewagon52]

Give an update when you have changed the plugs please.

[SteveAvery]

Shall do.

I've also just heard that an ECU reset may help. Any opinions on that?

[Connoisseur]

Worth it so the car 'forgets' previous patterns etc.

http://www.lexusownersclub.co.uk/forum/tutorials/article/17-resetting-sc430-engine-ecu/

[dave1]

Good idea, Michael.

I bought the red SC430 from Lexus, Cheltenham, who had just given the car an 80,000-mile service because it was 8 years old. It has also had a service every year, despite the low mileage.

Do you think that the plugs would have been changed recently or not, in one of these services? There is no way that I can find this out from Lexus, Cheltenham.

If the car has full service history c/w invoices it should be there. If invoices are not there then Lexus Cheltenham should be able to find out.

[SteveAvery]

Great! I didn't realize it was so easy. I'll do it after the new plugs are installed. I've ordered 8 NGK iridium IX BKR6EIX-11 3764 SPARK PLUGS. I hope that these are the right ones.

Actually, I've been toying with the idea - only toying, because it's so expensive - of getting an expert to upgrade the ECU to one that'll provide more bhp AND more mpg. I don't know if that is even possible, because I haven't investigated the subject yet. Now is a good time to ask, I suppose. Any opinions? Or is it only wishful thinking?

[SteveAvery]

Dave,

Although the handbook is stamped throughout by Lexus, there were no invoices. When I asked Cheltenham for them, they provided only very few reports, rather than invoices. It's all to do with privacy, I guess.

[dave1]

Most likely not changed - iirc plugs schedule is for change at 90k+ so the car may be on its originals. In the States many owners swap them after 30 to 60k miles. If changing then imo v. important to fit NGK Iridium plugs (OEM).

M

The interval for plugs on GS430 (same engine) recommended 5yrs/60k. Lexus Coventry changed the plugs on mine when I bought it in 2008 but I haven't changed them since as although 7 years it has only done 27k since and runs perfectly.

[dave1]

Dave,

Although the handbook is stamped throughout by Lexus, there were no invoices. When I asked Cheltenham for them, they provided only very few reports, rather than invoices. It's all to do with privacy, I guess.

They can get the full history if they can be bothered. Try Coventry or Lincoln as they are the same franchise.

[Connoisseur]

Most likely not changed - iirc plugs schedule is for change at 90k+ so the car may be on its originals. In the States many owners swap them after 30 to 60k miles. If changing then imo v. important to fit NGK Iridium plugs (OEM).

M

The interval for plugs on GS430 (same engine) recommended 5yrs/60k. Lexus Coventry changed the plugs on mine when I bought it in 2008 but I haven't changed them since as although 7 years it has only done 27k since and runs perfectly.

I guess that's down to different cars having different service needs/schedules.....

[ColinBarber]

I think all Lexus vehicles in the UK now have a 60k schedule for plugs, and have had for some time.

[SteveAvery]

I've already ordered a set; so, I might as well install them. I'll certainly post the result here.

[dave1]

Most likely not changed - iirc plugs schedule is for change at 90k+ so the car may be on its originals. In the States many owners swap them after 30 to 60k miles. If changing then imo v. important to fit NGK Iridium plugs (OEM).

M

The interval for plugs on GS430 (same engine) recommended 5yrs/60k. Lexus Coventry changed the plugs on mine when I bought it in 2008 but I haven't changed them since as although 7 years it has only done 27k since and runs perfectly.

I guess that's down to different cars having different service needs/schedules.....

The service needs/schedules with regard to plugs will be the same for the SC 430, GS 430 and LS 430 since they share the same engine Michael.

[Chris Skelton]

Red is nice!

For sale-where?

[SteveAvery]

Red SC430s are extremely rare, I'm afraid. I paid £20k for my 2006 one with 28k miles. Although it is currently very slow to accelerate, I now know how to solve this problem, thanks to various Lexus fora, and intend to keep it for ever.

It is my black SC430 that is for sale, not the red one. Sorry. It is shown in the picture at the left. Sep 2007 with 58,500 miles, and it goes like a rocket. I do not need two SC430s; so, I want only £12,839 for it.

[SteveAvery]

I disconnected the Battery, and, after two weeks' holiday, reconnected it. Lo and behold: the performance has improved dramatically!

The previous performance memory settings must have been cleared.

What a clever car, to adapt its performance to one's driving style!

I shall have to stop driving it economically, and drive like a maniac from now on.​

I have the new plugs, but shall get used to this new-found performance for a few months before I change them. Then I should be able to notice any difference they might make. I'll report the result back here at that time.

[Spacewagon52]

How long does the Battery normally have to be disconnected to clear the memory settings?

[Connoisseur]

How long does the battery normally have to be disconnected to clear the memory settings?

..about 30 seconds. This link gives the longer way around doing the reset but Battery off for 30 secs is effective