Interesting! So.....did they explain WHY this, "occasionally happens after an oil change"? What happens during an oil change that renders the ECU stupid all of a sudden??

 

In my experience, the Lexus seems to use a lot of electrical power especially when accelerating. If your battery or alternator are not putting out at proper levels, this could bring diminished power. I experienced that recently with a faulty alternator even though the battery was good.

 

roadfrog - I don't believe I've ever read some of the things you mentioned on your refresher prior to this thread. Especially about the Toyota Engine Oil System Cleaner. Good stuff there. I suppose it wouldn't hurt to do it on mine, even though mine has never done this. And mine is near an oil change too.

Don't read my post prior to your refresher as a negative, not intended to be. I 100% believe this phenomenon you guys have experienced. I hope I never experience it. I, like many others here, can't seem to wrap my head around what the trigger is that causes this hesitation. I don't believe it's due to the old oil being drained out. Because as far as the VVTI system goes, what's the difference at the VVTI system between draining oil out of the pan, and sitting the car all night with the oil draining to the pan? Both cases would have the same effect on the VVTI system (I think).

But ... pouring the new oil down on the top of the engine ... that could be causing oil to run across components of the VVTI system. I can't see why that would be a problem though. But it IS something that is different versus just sitting all night long.


JBedell - My 2010 model is on the original Panasonic. And I can tell it's not as strong as a fresh battery. I had a guy doing some work on the car the other day and he left it in the ON position (not running) for a couple hours as he was needing to put the windows up and down. When I got home to the car, it almost didn't crank. But after it did and I drove it, and it was still at 100% power as always. I realize this is just 1 instance / 1 vehicle. So, this may be different from other vehicles. Plus, cranking the car later that day while out, it started much easier ... which seems to indicate my alternator is A-OK.


7milesout

 

Yep...and I even posted a picture of the bottle. However, it appears that this product is unavailable in the US. Several members tried to obtain it, but were told it doesn't exist. Here's a pic again:

 

can you be a good and generous person, buy a can for each of us?

 

When i got my 460 last january i changed the oil and used Amsoil version of that but i had the hesitation. Lasted a week.

I changed oil yesterday didn't use any extra product and so far driven about 150 miles both city and highway. NO hesitation whats so ever.

I will report back in a few more days.

 

Has the engine ECM been reflashed? There is a service bulletin that speaks to this. My 2007 did the same thing after oil changes. I mentioned about the hesitation to the dealer. After a search of my service records he noted that the ECM had not been reflashed. My 2007 continues to run great after the refresh and subsequent oil changes.

 

Well funny you mentioned that. I actually did consider it.

 

I had mine done in March.

 

My previous 460 (2009) suffered these hesitation problems after every oil change for over 45,000 miles. It ran like crap for the first 2,000 miles after every oil change. Then it would run great!

A solution was finally found but after numerous "fixes" that did nothing. Those fixes included new engine heads & all new valves, pulling the transmission and replacing seals that "might have been" fouling an electrical loom that was routed through the transmission. .??. Reflashing was tried - did not help. All for nothing.... Mostly funded by Lexus and the dealer.

The fix (that actually solved the problem) was supposedly worked out by factory engineers and explained to me by my dealer's service manager. Solution: use only synthetic oil. Supposedly, Dino oil made the internal working of the engine "too noisy" and caused the knock detectors to retard the timing. He explained that. " As the oil became contaminated, it muted the engine noise and did not effect the knock sensor." Crazy at it sounds, the car ran perfectly with that fix until I traded it at 144,000 miles.

 

I've had the dreaded bogging in my 07L before. I do all the maintenance on my car. At the time, I was using Mobil 1 5-20w, the 5 quart jugs. I then switched to Mobil 1 0-20w Advanced Fuel Economy jugs, and haven't had the bogging ever since. This has been about 5-6 oil changes now.

 

And there you have it. It's what I have been saying all along. DevH summized the same thing. All I know is that my problem has disappeared for over two years now, and ONLY after switching to synthetic.

 

Well, it's a relief to know using full synthetic TGMO will minimize this problem. That's what my dealer used on my last oil change in March, and I will insist on it.

Since someone mentioned that ECM reprogramming fixed the issue for some folks, maybe this problem affects only 2012 and older vehicles. Has any CL member with 2013+ LS experienced this problem?


What to make of this?

 

Quote:Originally Posted by caha14 Definitely not a myth... I keep hearing about it at the dealership, even in cases when they use Toyota 0W20.I will be asking the Diagnostic Specialist at my dealership when I see him in the next several weeks. For years they have been using 0W20 pretty much exclusively on LS460s, so this was the context of our previous conversations. Mind you, in many cases you had other variables (which still triggered knock sensors, retarding spark, etc.), such as cylinder heads (part 2 of the service bulletin), but still, oil changes as a catalyst for hesitation were definitely happening.

 

Yes, I agree there probably are multiple variables involved. Hopefully, switching to TGMO synthetic and if needed an ECM "refresh" will solve the problem for most. I am still wondering whether this issue is restricted to some model years, say 2012 and older. In which case, there could be a connection to the engine management software that may have been resolved in 2013+ cars.