Coleroad

Six, techs don't make money when it takes a long time to diagnose a that for the moment is minor problem. If they can't find the problem quickly it's to their benefit to send it back out the door. Diagnostic is a flat rate time at the dealership. Usually it's one hour. A tech needs to do jobs on average at about half the flat rate to make good money. Him hooking it up to the computer I am assuming the car was warm. Since there was no codes he would need to do a live read of the sensors with the engine still cold to see what is happening in that situation. If it is a vacuum leak it is very minor and that can be a pita to find sometimes.

sixonemale

Agree with your thoughts. They had it overnight and started it cold, that's why it's very frustrating. We all know how these cars start and settle into a comfortable idle. So them telling me everything is working okay and charging me is not a good business model IMO.

Coleroad

No on the consumer side it's not. From the tech's view and the dealers it is. Since now I know they checked it cold. I would lean back to most likely being dirty iac , or a small air leak.

Coleroad

More than once I've seen this one from dealerships. Ac not working. Customer pays thousands for new compressor, condenser, drier, and be sent home with no working ac. Then come in and find out it was just an ambient air temperature sensor ($20 part). The sensor would be reading-40 degrees. Of course the ac won't run if it did at that temperature it would ruin it. I've encountered this multiple times. It's really sad. At least they didn't just start changing parts and not fix your problem. I'm sure there's others on here that have had that happen to them.

sixonemale

Does anyone have a good diagram that shows the vacuum hoses? Thanks in advance for posting.

sixonemale

I spoke with Toyota today and the conversation was simple, they immediately understood how Toyota/Lexus cars start up. They fully agreed and understood that they initially start-up at about 1,100 to 1,200 RPM and in about 30 seconds go down to about 800 to 900 RPM. I hope Lexus is reading this because to have a dealership that does not understand how their own cars start-up. They hook the car up to a computer and charge one hour of time and say there is nothing wrong, not good.

I'm going to replace the ECT sensor within the next day or so as my next step to solve this idle dilemma. I am purchasing an OEM sensor from Toyota.

Coleroad

Before heading out to buy one. Get your ohmmeter out read the resistance cold make note of it then warm the car up read it again. Cold it should read somewhere between 2,700 and 2,200. Bgw can probably get you the exact range from the shop manual. Do both readings with the ignition off so you don't throw a code. 2,700 should be about 50 degrees 2,200. about 80 degrees.

Coleroad

Lets go through this as a technician ( someone who diagnosis the problem exactly then repairs it). A mechanic replaces things he believes to be the problem till it's fixed. That's my take on the difference between the two. Go through this one thing at a time. Checking each thing till the problem is located then you can fix it. No sense in throwing parts and money at it till you find. Throw time and knowledge at it. Then the right part or parts.

Coleroad

Another thought, if the egr valve is letting just a small amount of leakage happen. That is a vacuum leak. Maybe just enough carbon has built up on the valve so it doesn't seal well, but not enough of a leak yet to throw a code. Another point in why vacuum leaks can be a pita.

Bgw70

Just wanted to let you know, it took about 90 second for my idle to go from 1200RPMs to 800RPMs. The temp was 67 degrees.

I have had the car for about a year, 63k miles when purchased, now 71k miles. The idle has always been this way...I think it is normal but then again maybe I have the same problem as you.
I am not going to worry about mine because it runs great.

sixonemale

After further research I chose to replace the ECT and had my mechanic do it yesterday. While changing the ECT, we inspected all vacuum hoses and the air intake system for possible leaks and did not find anything close to a leak, plus my mechanic said the engine sounded good and did not idle like it had a leak. This morning it was about 44 degrees, cool for this time of the year, and after starting the car and initially idling at 1,200 RPMs it seem to go down to about 1,000 RPMs within 30 seconds or so, I did not test for a lengthy period of time, but will test it one more time tomorrow. If the idle drops again in a fairly quick manner, problem solved. It the problem is solved, it's good to know that the ECT can degrade, before going bad, affecting the idle without throwing a code.

Coleroad

That sounds normal now to me. Glad it helped and was inexpensive.

sixonemale

I always give credit where credit is due. Bgw70 nailed my cold start idle dilemma some time ago, the PCV valve going slightly bad or getting somewhat plugged up seems to have been the source of the problem. I had purchased the valve quite awhile ago, but never installed it. After installation yesterday I tested it this morning with the outside ambient temperature of about 40 degrees and it started up at just over 1,100 RPMs and soon went below 1,000 RPMs and when completely warmed up with the auto climate off it still idles at around 600 RPMs.

Harold57

Glad to see that you got it resolved sixonemale.