Dr C

I figured that, if the mixture is richer than it should be, that the gas would, in fact, be deposited on the cylinder walls and be mixed in with the oil as the pistons moved up and down. I first encountered this when I had a car with three two barrel carburetors on it. The rich mixture was deluting the oil. I had to re-jet the carbs in order to correct the problem.

I understand that the mixture has to be richer when the engine is cold but there is an ideal mixture that my car may be exceeding. The idle goes up to about 1200 rpm when the mixture is richer. It usually takes about 5 minutes before the idle slows down. Now, though, this has me thinking so I will time it when the temp goes down again here in KS.

Bottom line. I would rather not have to take my car back in again because the red flag comes on. Hopefully Lexus will figure out what the problem is and get it fixed. I can't accept that it's my fault because I'm driving to from the same home to the same office. Nope. This one isn't my fault.

Bichon

My guess is that the reason that high idle is maintained a bit longer than folks may be used to in their other (perhaps older) cars is that Lexus wants to minimize the time to catalyst lightoff, in order to reduce overall emissions.

ES3

What does the idle eventually settle at?

Scotty99

In general it is not good for any car to make many short trips without a periodic long trip to ensure the oil gets fully up to temp. However you are right that these short trips should not be tripping your CEL. Maybe you had a bad tank of gas. Make sure you are running 91 octane or higher and it may not hurt to run a bottle of good fuel system cleaner (my favorite is Techron).

lexus27

iTrader: (1)

Dang, I got one of these CEL, Triangle with exclamation point and VSC (the picture with car and two skid marks on it, if that is what VSC is) today.

I have the IS350, 2.5 months old, 1850 miles.

The things is, for 98% of the time I've used the car, it's atleast a 25 mile drive and over 40 minutes of driving. So, no short trips for me. I've never pushed the car to red line and I babied it before the car is warmed up. I'll turn the car on again tonight and if the light remains, I'm taking it to the dealer.

BoSS250

i got the same thing the other day, i pulled my car in to the shop to get tinted and to change the bulbs and when i went to pull it out later that night the lights came on so i stoped the car poped the hood to see if the maf pulg was out every thing was find started it back up still on pulled out front turned it of went inside for about 20 min ounched out and called the dealer and be for they answered i was in my car and no lights on.. my car had about 300mi on it and i picked up the car on saturday.

IS2Sav

i mainly take the IS out on long drives on the weekend, but 1-2 days a week ill commute to school which is a few miles away. I always let the car fully warm up where the needle is at least about 1/4 up. But the point is we paid $40k for our car and it should be alot more reliable than my $5k honda civic dont you think?

mcfly

Please don't let your car sit and idle. Aside from being a complete waste, it's actually no better for your motor than driving it easily until it reaches operating temp.

gsrthomas

iTrader: (1)

I think these "short trips" thing is not what is causing the problem.

I never had to worry or think of short trips being bad for a car or causing the engine to malfunction. All the previous cars I've own never gave me problems with this.

Certainly this is a Lexus vehicle and short trips shouldnt harm the new IS. If it does then there should be a recall/fix to this because it is unacceptable.

Nobody is going to drive the longer way to work just for the engine warm up.

mcfly

With all due respect, your logic makes no sense. The fact that other cars you owned didn't exhibit a similar problem when driven for short trips has no relevance.

That being said, yes, Lexus should fix whatever is causing the problem. But again, behavoir of cars you've had in the past does not eliminate short trips from causing a problem another car.

Soda

I have 7k miles on my 350 and haven't had a problem other than the memory system doing wierd things! (knockin' on wood) But I do let my vehicle warm up for bout 5 mins before I drive and my drive is approx 5 miles each way.

Dr C

This morning, after driving about 5 miles, the idle was still at 1,000 rpm (at a stop light) and that was after leaving a heated garage and driving in 50 degree temperature. Is that normal?

TripleL

Dr C

I don't recall the RPMs at a stand still on mine (I think you have an AWD too?) but I can come really close to replicating your scenario tmo morning and let you know what I see.

Question: 'at the stop light was that 1000rpms with the car in gear? or neutral?'

In the mean time I'm sure that others will chime in for you

TripleL

Dr C

tripleL Yep, mine is AWD. When I took it out of gear the rpm's went up to about 1200.
After it had completely warmed up, the idle was more like 650 rpm.

TripleL

Dr C

Went for a ride this morning with my son to Home Depot and the short answer to your question seems to be 'yes' its normal in as much I can tell.

Here's the long answer:
-----------------------------------------
My car is garaged (although not heated) and the temp was 47 in the garage when I started up this morning. The car ran at 1800rpms for less then 30 seconds, then dropped down to 1500rpms at which time I backed up and started out.

First stop sign is a little over a mile away and the car was right at 1000rpms in gear. (btw now the outside temp is reading 28 degrees!)

At about 4.5 miles out I stopped at a traffic light and the car was at 900rpms in gear ( and I had time to determine that is was 1100rpms in neutral.)

At 8 miles I was at the stop light turning into the parking lot and it was at about 750rpms, which is about normal, maybe 50rpms high at the most.

---------------------------------------------

Of course none of this is conclusive of anything, but I wanted to take the opportunity to share and try to add a piece to the puzzle for you.

TripleL