Doublebase

Nice! Can you post the results when you get them? I don't think I've ever seen a used oil analysis of TGMO from one of our engines.

I've become a rather huge fan of this engine, so I imagine the results would be pretty good.

Devh

I'm sure replacing the heads solves the issue as I'm sure the dealer would like to stick the bill to the customer or Lexus. The VVT screens clogging is not a novel issue as it has plagued other Toyota cars and trucks. If excess knock is causing hesitation and retarding timing significantly then there would be a CEL.

Devh

My advice is not to trust the dealer. Request that your oil change is done with Toyota 0W-20 synthetic oil even if you have to pay the difference. I would also ask that the empty bottles are given to you after the work is completed just so they are reminded. I have heard of horror stories from the dealers not taking the time to do it right and quick filling the oil with what they have in bulk for all of their cars even though you requested Synthetic.
The guys that usually change the oil in dealerships are not mechanics and are usually low level workers that do nothing but change oil and rotate tires. They also over-tighten the oil filter and drain plug because they are in a rush to get to the next car. Any dealer that offers free or $20 oil changes are to be avoided if you want piece of mind and I would avoid any unnecessary multi-point inspections where they rummage though your car.

If it were me I would find a good independent and just bring him the Toyota oil and filter and request that a torque wrench is used when tightening the oil filter to it's specification.

roadfrog

https://www.clublexus.com/forums/att...eports-pdf.pdf

There ya go. That was my last one and hopefully this next analysis will be better. As you can see from the report, sodium was high which concerned me, but does not seem to indicate a coolant leak as potassium was ok.

I agree about the SES (CEL) light. Especially when the hesitation was so severe. Let's be clear....the "hesitation" was more like, "hell no, I won't go!". I would press the gas and the engine would not respond AT ALL....for several seconds and sometimes, even when it did respond, was way underpowered. This would happen several times in a few hundred to several hundred miles (weeks).

As for the head replacement, I'm only repeating what at least one person said. In his case, the head replacement was done under warranty, but the hesitation was still there afterwards and Lexus Corp was looking into what else may have been causing the issue.

Devh

If the heads were replaced maybe they put back the VVT solenoids without checking the screens. there are so many little things to obsess over when doing the job right but unfortunately those that work on the clock just do the bare minimum rather then investigate the primary source of the issue which is confirmed during the tear down.

As to the hesitation if the VVT screens are obstructed or the tiny passages are occluded it will cause hesitation and delay in power however if the solenoid is at fault then it would throw a CEL.

williakz

Don't know about the factory fill, but I would imagine it remains constant for long periods of time.

Dealer fills vary widely, often depending on the best deal the purchasing department managed to negotiate. My dealer in Alabama (a Sonic unit) has used Pennzoil Platinum 0W-20 for years (written right on service order). I've always used the same oil (in self-changes after dealer freebies) so that there's no brand/viscosity issues if I ever have to press a serious engine warranty claim against my dealer/Lexus.

Johnhw2

Thanks! My dealer only gives first two changes free. It's park place lexus in Plano, the only Malcolm Baldridge award winning dealer. This is a quality award for having good processes and following them. I will ask for a synthetic and get the empties back to remind them.

I looked up factory fill and found the owners manual indicates TGMO is used.

williakz

I would recommend you find your dealership's "default" fill (it'll be synthetic), then determine whether that particular oil meets your standards. I would forget about the "empties" (they pump oil by the drum anyway at dealerships). Just have have them document the oil brand/type/viscosity used right on your service record.

CRowe14

It appears I've placed my question in the wrong thread (Oil change)
This is where I meant to place it, my apologies.
Interesting here...
I purchased my car from a GMC dealership who did the oil change about 1500 miles ago.
I've read the numerous entries regarding hesitation upon stepping on the gas and the effects the different oils can have on the engine (namely Road Frogs well documented situation) so I was a bit weary when I saw that a GMC dealership did the last oil change.
Not sure if I'm being overly OCD or if there is anything there, but every once in a while, there is a very slight hesitation when I step on the gas, but it's very subtle. I also haven't driven it alot so that may have something to do with it as well (more lending to the ideal that I'm not completely accustomed to how this vehicle drives).
I was decided on the fact that I should just allow this oil to cycle through-miles wise then get the Toyota blend with an additive on the next change.
What do you guys think?

Doublebase

Excellent, thanks.

I would think the high sodium reading was because of the Super Tech you said you used, they and Valvoline, Carquest, and Napa, all use a sodium additive for their protection pack.

Was it the Quaker State Ultimate Durability that gave you those hesitation problems? I always see it on sale.

Trumpanche

Follow-up after using 0W-20 for the first time:

Right after the oil change I took a long trip and there were a couple instances of extreme hesitation and the usual jerkiness for a few hundred more miles after that. About 1200 miles after the oil change, I felt like everything was fully back to normal where the acceleration is smooth and effortless etc. I suppose I'll do one more oil change at 5k and cross my fingers, but if I still get hesitation next time, I think I'll go to a 10k mile oil change interval to minimize the amount of time I have to deal with the issue. At least that's my current thinking... and I've changed my mind on this at least half a dozen times before.

roadfrog

On your next change, I would seriously consider using the Toyota Oil System cleaner like I did. I have not had anymore instances of this hesitation since I did that.

Also, you state that you used 0W20. Did you use Toyota branded oil?

Trumpanche

Roadfrog - no, I used the Pennzoil Ultra Platinum 0W-20. In retrospect, going with the Toyota oil may have made more sense, but my thinking at the time was to maximize the cleaning and that's what the Pennzoil is marketed for so I went for it...

I had also added an engine system cleaner (Marvel) a few hundred miles before the oil change to hopefully get the cleaning kicked off before adding the new oil. Can't say what, if anything, that accomplished.

roadfrog

You really need to give the Toyota stuff a chance. It's not cheap - about 25 bucks, but it's specifically formulated for the VVT-I systems used in the LS.

Again, I can only go by my personal results from using the Toyota oil and their cleaner. My hesitation issues are no more after using them. Based on that, I'm done with using anything but the Toyota products. I just think the VVT-I system in our cars are just too sensitive to anything else. My car is a dream to drive now and is soooo smooth. I was very concerned when these issues cropped up last year. EVERY oil change resulted in severe hesitation - even with quality oils. I will continue to espouse the benefits of my results in the hopes that it will help others in the same boat.

Lavrishevo

iTrader: (1)

Maybe the cleaner played a big factor in eliminating the issue. Especially, if something was clogged and oil was not circulating properly.