'13 3.6r iam @ 0.3375

[gimpydingo]

After going through vac leaks and such on my 07 LGT (fixed, knock on wood!) I am now having some issues with my 3.6. While driving home I noticed a metallic/knocking sound when I hit the gas, I could hear the sound bouncing off the retaining wall. Since I was stuck in traffic for 2.5 hours on the way home last night I had to pull the info this morning, so I'll need to do some logging.

 

When I pulled up romraider it shows my IAM at 0.3375 with some FLKC. A/F is all good between 0 to +/- 2.5. I am wondering if I have a loose heat shield or possible some bad gas? Any suggestions and suggestions on what to log just to capture what I need?

 

2013 3.6R, 37,000 miles, stock.

 

EDIT: More details.

 

Thanks!

[Perscitus]

Might be normal on a stock tune. The topic of IAM with the EZ36D with the Denso ECU is a complicated one....

 

With the 6th gens running Hitachi ECUs at least its known that IAM actually fluctuates a fair bit (even with each ignition cycle) and does not give a good indicator of engine or tune 'health' as it did in the past, particularly on boosted H4s.

 

Since all the A/F Learn ranges appear to be good (both banks?) then at least the MAF scaling and load, load comp should be OK.

 

You'd likely want to gather a fair amount of logs that include:

 

Gear, RPM, MAFv, Load,

Total Timing, Learned Timing,

FKC, FLKC, IAM,

AFR#1, AFR #2,

Fuel Learn/Correct (#1 & #2)

Fuel Learn/Correct (#3 & #4)- optional but would be good to see the fuel contributions from the rear O2s

Intake Temp, Coolant Temp (optional), Engine Oil Temp (optional)

 

Then you should analyze your Knock Retard from the logs and see where timing is being added/removed and where/when IAM is changing (ECU enters Rough Correction mode). I wouldn't rely on LV and IAM changes alone to asses.

 

Best to plot Knock Retard vs Load and Knock Retard vs MAFv, sometimes also vs RPM, filtering by gear to see if you're getting most noise in 4th/5th or across lower gears as well.

 

And in terms of logs, if you log both FKC and FLKC, setup an extra column called 'Knock Retard' and setup a function like Kodename47 mentions in the RR thread below.

 

=IF(A2<A1,A2,IF(B2<B1,B2,0))

where

A = FLKC Column

B = FBKC Column

 

See Kodename47's post: Wed Jun 01, 2016 6:50 pm

http://www.romraider.com/forum/viewtopic.php?f=15&t=12870

 

Then you can use VGIs excellent Java-based tool to do the analysis Kodename mentions, fit the data over your Base Timing table row/columns to get a good idea where timing should be pulled and/or where you have issue (if you choose to leave it as-is for now).

[gimpydingo]

Awesome thanks. I was going to PM you as someone suggested. I'll pull some logs and do some plotting to get a better idea. Just hearing that knock sound was a bit concerning, but I'll look over the car for any mechanical issues. I'll post up when I get a chance. Not driving the car this week and will be home until Tuesday starting tomorrow, so I'll have time this weekend.

[Perscitus]

I've heard through the grape-wine that you're running AKI87 (any E** mix?).

That alone could explain the IAM drop.

 

Sure the car is 'rated' to run on AKI87, but that doesn't mean Subaru's knock prevention strategy will not bring IAM down to allow it

 

Try a tank of AKI91 or AKI93 (ideally ethanol free, if available) from a frequently used station and see what happens.

 

The H6s a. run hot b. have a relatively high compression ratio, which is dynamically raised further by AVCS/VVT and both of these factors don't mix well with lower octane gas.

 

Let us know if a tankful of AKI91/93 makes a difference or allows RC mode to bump your IAM back up to >0.8 or pegs it at 1.

[gimpydingo]

I'm in CA, so yeah crap gas. Not winter so will check on the non ethanol. I realized I actually got gas from a station I don't normally use, a 76 to boot. I'll go back to the regular Chevron and go with 91 (max I can get). Thanks again. Different animal than the GT's huh.

[gimpydingo]

Working from home this week so have not had much time to drive the car. Something odd, I cleaned the MAF and tightened somethings up. I got 91 OCT gas and reset the ECU. The odd part being the IAM starts at 0.000 and not 0.500. Possible issue reading the ECU?

[Golferdude1087]

No, pretty sure IAM will start at 0 and then go up from there. It makes sense since the car would prefer to add timing rather then pull. It should go up shortly. Maybe perscitus could give a more detailed explanation why

 

Sent from my VS986 using Tapatalk

[gimpydingo]

I just know on the GT that is starts at 0.500 or 0.750 with a tune. I saw another post about a 3.0 that the IAM starts at the usual 0.500. Hmmm

[Timothy.B]

I had to reload my stock ROM and do a few logs and after resetting, IAM was at 1.

[Perscitus]

Guys, please read my Knock Strategy sticky.

 

On the 3.6R, stock ROMs are configured such that after pulling the battery or resetting the ECU, IAM defaults to an initial value of 0.00 (most tuners will set this initial value to 0.50 or 1.00).

 

Even if set to 1.00, at first cold startup after a reset or reflash IAM will be at 0.00 while under OL as the coolant warms up to operating temp. Once its there, now unde CL, and you let her idle for a few seconds (say at an intersection) it will toggle to its initial value... say 1.00.

 

From there what I outline in the sticky thread occurs. FKC activates first, RC activates if you hit specific load, rpm thresholds, then IAM can but doesnt have to re-evaluate, and back to FKC/FLKC (once IAM resettles).

 

The only IAM you should care about (and only somewhat on an N/A) is the one you see once you notice some FLKC learning to add or subtract timing. Only at that point has the IAM settled on a value the ECU is temporarily happy with.

 

Initial IAM, or the IAM you see/log when only FKC is active are not very telling.

IAM changes (either up to 1.00 or down from 1.00) can only occur in RC mode and they give you an idea of what the ECU thinks it needs to do to reach somewhat stable limited-knock timing... IAM raising up toward 1.00 is a good sign, shifting around close to 1.00 is ok, normal, dropping below 0.5 or staying pegged at 0.00 (meanwhile you still see <-4degs FKC or FLKC) is not.

 

A lot also depends on the IAM stepper value. By default its set to 0.5 and decays from there... which means if your Initial IAM is set to 1.0, as soon as RC triggers, IAM will drop to 0.5, then either go up or down from there based on knock sensors feedback counters. First by 0.25, then 0.125, etc. Decaying unless more drastic IAM changes are called for.

[gimpydingo]

Finally back. Ran some new gas and kept checking the numbers, IAM finally settled back at 1. New issue being the oil consumption. Almost at that quart per 1000 miles. I'll be calling Subby corp about this and get the wiper motor recall fixed at the same time they start the oil consumption tests. Ugh!

[Golferdude1087]

Finally back. Ran some new gas and kept checking the numbers, IAM finally settled back at 1. New issue being the oil consumption. Almost at that quart per 1000 miles. I'll be calling Subby corp about this and get the wiper motor recall fixed at the same time they start the oil consumption tests. Ugh!

 

Sadly oil consumption is a Subaru issue throughout all models. That said, that is a lot. Look at the Nanotech lubricant thread, it helps tremendously with consumption

[Timothy.B]

Seems to have taken a few bottles of the Nanotech to reduce consumption. This time around I'm at 800 miles and it appears to have barely moved. A quart for 1000 miles is a lot. Could also run the thicker 5w40 as well. Good luck on the consumption tests!

[gimpydingo]

I'm just worried about good ol ringland, with the 1QT/1000 miles. Still tracking a bit longer to get a better idea of mileage.

[fahr_side]

I'm just worried about good ol ringland, with the 1QT/1000 miles. Still tracking a bit longer to get a better idea of mileage.

 

 

 

Never seen broken ringlands on n/a models.