djpeakSD

So my car has 12k miles on it and I got it over a year ago. Some of you may of remember me posting a video of my abnormal idle about a month ago. When the idle happened I asked my advisor about it, and he said "Well if there is no engine light we cannot diagnose it" blah blah blah.

So I did get an engine light last week, I believe it was p303 (misfire) so I took it in and they have had the car over a week now, and the most recent update is that there was a significant amount of carbon buildup so they are doing a full engine carbon clean out (he said it different than that) but said they aren't just running some additives through the car but that they are actually taking the engine apart to clean.

I do get gas at valero and Arco/Usa gas. I guess I will be getting gas from shell or chevron from now on.

BarrettF77

I just use Quick Trip. Always had good luck there. I've used valero for a long time in other cars. Don't really know of any mechanical issues from it per say, but they are always far and few in between here and I get more benefit with QT and getting points there.

jkeifer3

I don't think there is anything particularly wrong with Valero or Arco gas. If that were so, there'd be quite an uproar as lots of people use it.

djpeakSD

I wonder why my car has a significant amount of carbon buildup? What else would cause this besides cheap gas, any thoughts?

homeboyv

Personally I typically stick to Shell or Mobil if a Shell isn't around. Some people feel that the quality of gas is all the same but I beg to differ. IMO you get what you pay for...

Joeb427

iTrader: (1)

bitkahuna

iTrader: (20)

do you do lots and lots of short trips or sit in traffic a lot?

bruce van

I stay away from any brand that is not Chevron or Shell. Some people will tell it's all the same, and from your experience, it's not.

I've had pretty good luck with reliable cars following this rule and it seems to have helped.

GSthe4th

iTrader: (1)

Honestly DJ I am sorry this happened to you and your car. While I cannot say it was the fuel alone as I have no real knowledge, I am pretty sure it is at a minimum partially to blame. I must agree here, 1) Chevron, if not 2) Shell. I worked for a Chevron jobber in high school, and the difference was explained to me then, much of which I dont remember. Of course I was young and impressionable then, but it made sense. The one thing I remember is that a tanker ALWAYS had to have the tanks steam cleaned before hauling a load of Chevron gas, unless it was dedicated to Chevron fuel. The smell is also different, look at the stains on the concrete at various gas stations. I used to LOVE the smell when I was loading up 5K gallons into our rigs!

larryinWA

I've been using Costco gas. It's reported to be good quality. Anyone know who makes it for Costco? Other than that, I prefer Chevron.

a310pilot

Oh no not MISFIRES again. This is a known Lexus issue and since a long time. MY 2006 GS had it and it had it with all cylinders. Started with one and spread like a virus to all of them eventually. Lexus did engine wash and whole bunch of other stuff but it used to keep coming back... eventually they took the whole engine apart and serviced it including changing valve springs. Car drove brand new again but after another 30k km it started to come back. Do a search on rough idle and you'll come up with thousands of links. Lexus IS same issue and with many different year models.

Now this is a different engine so I had my fingers crossed that this would be fixed. I just hope this is random one and isolated with your car... feel for you man. If you going to keep the car over warranty this is a sign to buy Lexus extended warranty and only get the one which covers this issue... Because I have a feeling this won't be your last time. Although I wish it is.

BarrettF77

You also want to be sure and occasionally redline the engine heavily from a stop. You will see a large light black soot blow out the back which is carbon buildup being blown out.

It's funny how those who push their engines hard more frequently have fewer issues. I'm not saying you do or don't, but it's worth doing off and on. Plus it's fun.

bigblack06

iTrader: (20)

+1 on this.

mrpartsman

u are right , I go for Shell first then Chevron, my third option will be Mobil, but stick to one gas trust me Gas makes a big difference, there has to something different in it, that keeps the valves clean, and thats y there is always price difference, u get what u pay for , but I hope u get ur problem fixed.

Outrage

Carbon deposits on the spark plug electrodes are typically caused by an air/fuel mixture which is too rich or spark plugs which are too cold.