8AR engine internals look
01-31-19, 11:11 AM
#16
I let the engine idle for about 2-3 minutes after long highway driving or after some hard drives. is it necessary to let it idle for a couple minutes with light city driving?
01-31-19, 11:17 AM
#17
Intermediate
It was two 8AR-FTS engines, not one. One had 60k and the other 61k. They both had the same issue, which is an issue we are inspecting for the 8AR. I would rather not talk about the issue because I don't want to start some kind of false panic. If it turns out to actually be a large scale problem, you would hear about it as a recall. Nothing you could do about it but worry anyways. If you are having your services done at a dealership, they are trained to look for known issues during inspection. It's not something that will make the engine blow up or anything.
I will say, NOT RELATED TO THIS ISSUE, I don't think a single driver does the turbo cool down time procedure on the NX200/300,IS200 and RC200 when parking. Am I correct?
Acheuk, You are correct. These engines are direct injection and port injection. The port injection is periodic for cleaning purposes, not all the time.
Loophole, These engine were brought to Lexus for break down, inspection and parts replacement. I did not put the miles on them. The owners stated that followed the rules of premium fuel. I will agree that the carbon build up on DI only engines was much worse.
I will say, NOT RELATED TO THIS ISSUE, I don't think a single driver does the turbo cool down time procedure on the NX200/300,IS200 and RC200 when parking. Am I correct?
Acheuk, You are correct. These engines are direct injection and port injection. The port injection is periodic for cleaning purposes, not all the time.
Loophole, These engine were brought to Lexus for break down, inspection and parts replacement. I did not put the miles on them. The owners stated that followed the rules of premium fuel. I will agree that the carbon build up on DI only engines was much worse.
'That amount of carbon build up worries me a bit... spoke with a tech last week saying that carbon build up should not be there due to port injection, and even so it should not appear until at least 100k miles.
I'm having issues with knock correction learn value being low, which is retarding my timing. The tech is blaming fuel, but I wonder if build up is affecting that.
01-31-19, 12:31 PM
#18
Lead Lap
Thread Starter
I would blame fuel too. That is a response by the engine from the knock sensor being tripped too many times. I would wager bad fuel, low grade fuel, extremely cold start up, water in fuel etc. If you had the car checked at a dealership, the Lexus tech is informed by TIS to check octane, ethanol and water levels. Meaning he can test your fuel instead of guessing. What did he say? Are you/have you used low grade or cheap (**** gas station) fuel?
01-31-19, 12:32 PM
#19
Lead Lap
Thread Starter
01-31-19, 01:30 PM
#20
Is the idle time really necessary? My previous GTI had an auxiliary pump that would continue to run coolant through the turbo after a shut down. I let my is200t idle for about 30 second max after a high speed drive. I'm at 78k miles now and 0 problems so far.
01-31-19, 01:46 PM
#21
Intermediate
I commend you on following the procedure. Not many do.
I would blame fuel too. That is a response by the engine from the knock sensor being tripped too many times. I would wager bad fuel, low grade fuel, extremely cold start up, water in fuel etc. If you had the car checked at a dealership, the Lexus tech is informed by TIS to check octane, ethanol and water levels. Meaning he can test your fuel instead of guessing. What did he say? Are you/have you used low grade or cheap (**** gas station) fuel?
I would blame fuel too. That is a response by the engine from the knock sensor being tripped too many times. I would wager bad fuel, low grade fuel, extremely cold start up, water in fuel etc. If you had the car checked at a dealership, the Lexus tech is informed by TIS to check octane, ethanol and water levels. Meaning he can test your fuel instead of guessing. What did he say? Are you/have you used low grade or cheap (**** gas station) fuel?
My knock correction was degraded to 17.8 degrees. Nominal is 20 degrees, and a degrade from low-octane fuel is 18-19. Since the degrade was even worse than of using low-octane fuel, I find it hard to believe that the fuel I am using is the sole cause... I always use 91 (max octane in CA) and primarily use Costco gas, but will refuel at Shell or Chevron when more convenient. Never at the no-name places.
01-31-19, 01:47 PM
#22
Intermediate
The 200t does not have that system in place as far as I know. Since the manual specifies a cool down period, I would definitely follow it just to be safe if heavy driving was involved.
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skyshadow (02-05-19)
01-31-19, 02:51 PM
#23
Pit Crew
Ugh! After watching that video and looking at how similar the Ford block is to the Lexus block I'm feeling concerned. That 2.3 liter Ford engine is in a number of Ford products and I would be interested to see if that engine in other applications is having the same problem.
02-01-19, 08:29 AM
#24
Lead Lap
Thread Starter
Pngo, you might be over generalizing the problem. Maybe it was bad fuel and a cold start up? Maybe bad fuel with water in it. The tech should have tested your fuel. Did you throw a AFR code?
02-01-19, 08:31 AM
#25
Lead Lap
Thread Starter
RVague, Don't worry. Seriously almost all modern blocks are open deck. Only high performance blocks are semi closed or closed. In fact, if you listed the last 3 cars you've owned to me, I bet their blocks were open deck.
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rVague (02-01-19)
02-01-19, 08:37 AM
#26
Lead Lap
Thread Starter
You are right, if used VERY incorrectly it can hurt things. But, I called a local dealership and they told me when you have your throttle body cleaned they spray a can of B12 Chemtool into the intake (while running & holding 3k rpm) and pour another can in the tank. That being said, I would assume the cat is safe. If it could damage the cat, dealerships wouldn't do it.
02-01-19, 10:24 AM
#27
Intermediate
As I understand it, the knock correction LEARN value changes over a long period of driving and acts as a global... the tech was saying that it typically takes 2-3 tanks of fuel to affect that value. When I brought it in, my tank was nearly full as I had just filled up the day prior. So if what the tech is saying is true and that it takes a while for the KCLV to change, then that particular tank of fuel should not have affected it that dramatically so quickly.
No codes showed up. I wish I had known they could easily test the fuel like that - I will keep that in mind for next time. At the moment, I am switching to Chevron fuel as recommended by the tech to see if it changes anything.
02-01-19, 11:28 AM
#28
Intermediate
In regards of blocks with semi-closed or closed design on high-performance cars, Ford Focus RS is a high-performance car and has open deck block.
Last edited by Lex2000TL; 02-01-19 at 11:32 AM.
02-01-19, 09:59 PM
#29
Pit Crew
Good article on open dock vs closed deck blocks. From the article: “The downside to an open deck is that it provides the least amount of structural support at the top of the cylinder walls, where they need it most. This reason alone makes an open deck block the least reliable choice for almost any type of forced induction or nitrous application, and should be left to low compression, naturally aspirated engines and low boost platforms.”
So this does concern me.
https://www.enginelabs.com/news/supp...r-closed-deck/
So this does concern me.
https://www.enginelabs.com/news/supp...r-closed-deck/
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Lex2000TL (02-02-19)
02-02-19, 10:52 AM
#30
Lead Lap
Thread Starter
Same place I got the "data" that open decks are not death sentences, Experience. For example, how you think you got the pics of the 8AR broke down. You think it wished its way like that?