Subaru Forester Owners Forum banner

DIT engine and Subaru upper engine cleaner....anyone doing this?

('14-'18) 
69K views 57 replies 28 participants last post by  DrWebster 
#1 ·
Was wondering if anybody with the FA20DIT has had this service done (or have done it themselves).....and if so, how often should this be done and starting when.......not sure if our DIT's will be prone to developing the carbon build up on the backside of the valves (do to loss of fuel wash typical of port injection) that so many other DIT's have suffered from.....so was thinking that this would be good money spent on preventative maintenance and piece of mind........

Only thing that concerns me is what I came across in another post about the Ford Ecoboost engines grenading the turbos after use of what I'm assuming is a similar product which created too much heat in the exhaust manifold where the turbo is near or sits in and super heating the turbo and destroying it either immediately or shortly thereafter.......

I ask because I believe this upper engine cleaner is a recommended maintenance for ALL Subaru engines???.....but I don't want to do this at the expense (literally) of the turbo.....so kinda not sure what to do here...any input from a Subaru tech would also be helpful......thanks...
 
#3 ·
Ed.....The cleaner I am referring to is an aerosol can that is sprayed directly into the intake through a vacuum line (similar to a seafoam treatment)......Subaru has their own which they call Subaru upper engine cleaner.....this is different than the fuel system/injection cleaner that is added to the gas tank (although Subaru has its own fuel system additive as well that they recommend be done at the same time of doing this upper engine clean)...
 
#7 ·
Thanks for the info and explanation on this product. I suppose CRC and the like have developed a pretty powerful cleaner to de- gunk the valves of a direct injection motor. I DONT KNOW IF THE MEDICINE
IS WORTH THE CURE,if you know what I mean.Some of my worries about using this stuff are;Would it harm the piston rings and cyl walls
by washing away the oil.Could some of the product get into the crankcase and dilute the engine oil.What happens to the caked on carbon that this product removes,can it partially clog up the cat.converters. These are some of the reasons why I'm not going out to buy a can of the stuff tonight!. ed
 
#6 · (Edited)
Was wondering if anybody with the FA20DIT has had this service done (or have done it themselves).....and if so, how often should this be done and starting when.......
There was some discussion about the Subaru SA459 upper engine cleaner in the ‘Oil Catch Can install’ thread here.

I would be very concerned if this wasn’t being used on my Subaru at each service.

FleaDog found an interesting thread on nasioc forums about carbon buildup on the 2015 WRX (see link in my following post).
 
#10 ·
Thanks for the info and the links .......

I have to admit though.....I am a bit upset with the fact that we likely have an issue requiring active preventative maintenance..... however....there appears to be no real "safe" (I think?) preventative maintenance for this issue out there??.....and using the seafoam or Subaru upper engine cleaner is a big question mark in the FA20DIT because of the possibility of damage to the turbo?? (if you take the findings with the Ford Ecoboost engines as an example).....talk about a serious case of "you're damned if you do and you're damned if you don't"......
 
#14 ·
I have to admit though.....I am a bit upset with the fact that we likely have an issue requiring active preventative maintenance..... however....there appears to be no real "safe" (I think?) preventative maintenance for this issue out there??.....and using the seafoam or Subaru upper engine cleaner is a big question mark in the FA20DIT because of the possibility of damage to the turbo?? (if you take the findings with the Ford Ecoboost engines as an example).....talk about a serious case of "you're damned if you do and you're damned if you don't"......
Thanks for mentioning the Ford Ecoboost engines, some information posted makes interesting reading - I can understand your concerns. In regards to the turbo concerns, I’m not convinced we are comparing apples with apples when comparing that engine with the Subaru FA20DIT.

I agree with slothman’s earlier comments. I think the preventative maintenance is to use the Subaru SA459 upper engine cleaner at each service as specified in the Australian owner's maintenance schedule. Whether this will be good enough to clean the underneath side of the inlet valves is an unknown (to me anyway), but I believe it is effective in cleaning the combustion chamber & piston tops as well as the throttlebody (when applied before the throttlebody) so it may also be good enough to clean underneath the inlet valves.

With this (SJ XT) engine I have been informed that only 1/2 a can of SA459 is being used at each service to eliminate risk of hydraulic lockup, so maybe the remaining 1/2 can can be used in between the regular 6mth or 12,500km scheduled services. But as mentioned in my post in the other thread I linked to, there isn’t an easy way of doing this compared to previous models, although Danoz’s catch can install has overcome this.

Even though the Australian owner’s maintenance schedule doesn’t list the Subaru SA718 Fuel Additive, Subaru Australia’s website recommends this cleaner to be used every 6,000kms. See Fuel System - Carbon Maintenance | Subaru Genuine Parts for the Subaru SA718 Fuel Additive with the Subaru SA459 Upper Cylinder (Engine) Cleaner below this.

I use the Subaru SA718 Fuel Additive & the Subaru SA459 Upper Engine Cleaner at each 6mth or 12,500km scheduled services, hopefully it will prevent some of the build-up underneath the inlet valves.
 
#11 ·
Just took the XT out for some spirited driving after adding a bottle of techron to the tank....not sure what else to do than adding a bottle every now and then and changing the oil more frequently.... If it's going to gunk up its going to do so no matter what I do..... Sucks to say the least..


Sent from AutoGuide.com Free App
 
#16 ·
Any reason why not? I had a Subaru Service Manager try and explain to me how I needed BG 44K instead of the Subaru Upper Engine Cleaning procedure because of the fact that the injector is right above the valve and the 44K stuff would clean it off lickity split. I mentioned the fact that it was a direct injection motor and he goes, "They're all the same. It will rinse the carbon right off"

:facepalm
 
#19 ·
I am pretty sure I am going to get the top engine cleaner, as well as the carbon clean this week and knock it out. Going to get the tool as well since I think it might be worth doing again later. The car has 62K so far, and I plan on keeping it awhile. It's kinda awesome at Stage 2+ (should have come this way from Subaru IMO)

Sent from my SM-N900V using Tapatalk
 
#20 ·
So I did the Carbon Clean and Top Engine Clean yesterday.

Got the tool and ran the car with it.

Went rather smoothly, but didn't have as much white smoke come out the exhaust.

I can say that it seemed to idle a touch better and had a slightly noticeable increase in acceleration. Now, that is from the butt dyno and is my perception, but having been behind the wheel for 63K miles now, I can tell the difference.

As a side note, I now have the tool to do the top engine clean, so I will probably do it before every oil change. If anyone in the Denver area needs to borrow it, hit me up.


Sent from my SM-N900V using Tapatalk
 
#24 ·
The dealer that refused to quote an upper engine cleaning for me also failed to replace my PCV valve at 60kmiles despite assuring me on the phone that it would be done...when I called them on it after checking my paperwork, they told me they didn't do it for turbos because it was too much work (I figured out the intercooler needs to be removed). They pointed to some verbiage in their service summary that said the PCV valve is only changed at 60k "if applicable", and I had no proof of the verbal assurance I had been given. I really regret having my 30k and 60kmile services done at this place and they will never see my vehicle again as long as I own it.

So, it seems like the dealerships in the US have a lot of leeway as to what interval services they will bother to perform...Canada is likely more tightly regulated, but it's probably worth getting something in writing about getting the injector cleaning service, including the carbon clean, done at 60,000km from your dealer.
 
#26 · (Edited)
It is pretty much listed on the bottle. Use the tool to put 1/3 of the bottle into the engine, let it do its thing in the engine while it is running, then repeat 3 times until it is gone. Once the car runs normal (slightly rough idle at first),then drive it. Pretty simple.

Sent from my SM-N900V using Tapatalk
 
#27 ·
I have the tool now, so if anyone here in the Denver area wants to do the service, they are more than welcome to use it. I kept one of the empty bottles and maybe at the next service I might use a different solvent like Liquid Moly or something. The carbon clean and the top engine cleaner was not too much, so we'll see....

Another question for you all:
So regardless of what vacuum line you attach it to, it may not get all of the cylinders equally. Why not pull the intercooler out and replace that with a few pieces of 2" PVC and some connectors to keep the intake track together and install a small tubing nipple on the end of that right in front of the throttle body? That way ALL the cylinders get close to the same amount of the intake cleaner? Just a thought. I may just do that next time I do a cleaning before an oil change.
 
#28 ·
I've been using the Subaru Carbon cleaner with the subaru tool as well. I ran a couple bottles prior to an oil change the first time I did it (@ 42k miles) and plan to do 1 bottle of carbon clean before each oil change. I don't know if it's really doing anything but I do think I worked out a little carbon after the second bottle. I did feel a little stronger but who knows if it really is.
 
#29 ·
I worked for a Subaru dealer and Honda Dealer as service manager, I have seen good results from top end cleaners in fact Honda has a service bulletin out for a civic on that. but back to Subaru sorry i would say yes it's worth doing but if you use good gas like chevron it's not needed as often. our service department sold bg products it was good i still use to this day myself.
 
#31 ·
Throwing in my 2 cents. I've only got 30,000 miles. I am running a stage 2 but wasn't looking for full blown power and I've only got about 3500-4000 miles on this stage. Due to some fine tuning issues with my ProTune I decided to do the TGV delete. (My tuner and I saw some strange goings on regarding the TGV's) Since I didn't want to be throwing codes between installing the deletes and seeing my tuner I zip tied them in safe places and left them plugged in. The number one thing I noticed was the carbon build up on the valve flaps of the TGV's. After working on the tune for a while and doing a test drive, with what hopefully is the final tune for a while, I showed my tuner the gunk on the valves and he was really surprised considering my mileage. I also promptly ordered an AOS. I know there's varying opinions on AOS vs. dual catch cans etc. That's for another discussion. It is the route I chose to go for my own reasons.

I would highly suggest at minimum pulling the intake manifold and taking a look at the TGV's and, if they look gunked up, looking at your intake valves every 25-30,000 miles. This is the own of the downfalls of the DIT design combined with the stock oil recovery system. In my case a combination of carbon/oil build up, and probably a bad tank of gas from my regular Shell Station, was leading to top end knock when running my turbo at the same boost settings it was already at before the deletes. In short it is killing my octane retention. I will be doing the top end clean today! I'm literally out the door to pickup the kit after this post.:wink2:

I would definitely recommend doing the top end clean on the FA20DIT motors. If you are a hard runner or or tuning your car you probably want to look at adding an AOS or dual catch can setup.
If you are just a daily driver, make lots of short trips, or don't put very many miles on your car per year I would recommend doing it every 25-45k miles. Or at least once a year. You know what they say about an ounce of prevention...

If you live in a state like mine (CA) where we are stuck with E10 91 octane. I also suggest using a quality fuel system treatment/stabilizer/octane booster. By quality I mean a 100% petroleum product. Lucas has an octane booster and separately a ethanol stabilizer both of which are 100% petroleum products. Klotz makes great products and their octane booster is a pure petroleum and also helps to remove water from your fuel system. I was a long time Seafoam user but after having a weird experience in one of my cars I started doing more research on additives. They say their product is 100% petroleum but it isn't. If you read their MSDS it states it's up to 25% isopropyl alcohol. The whole point of using an additive is negate the problems the Ethanol is causing as far as water retention and gumming up the works.

Good information on some of the additives can be found here: Is your gas additive safe with E10 fuel?

To sum up if your dealer doesn't offer it and you own a 2014+ XT I recommend you buy the kit online and use it preventatively. There is a lot of consistent information on the interwebs on why DI, especially turbocharged ones should do this preventively. One look at the back sides of the intake valve pictures will blow your mind!
If you have the 2.5 motor, even with the PZEV, 45-60k miles is probably a good call for the cleaning kit. Once again, just like "regular" oil maintenance, how you drive, where you drive and the fuel you use are all factors to take into consideration.

I prefer to error on the side of caution like changing my oil filters 1/2 between every oil change and even though I use high quality oil changing it 1000-1500 miles earlier than factory recommended.
 
#33 ·
I ordered the tool and bottles of top engine cleaner and carbon cleaner from Heuberger in CO Springs, could not find the tool on Amazon and many other dealerships said it was out of stock. Hope the tool actually shows up!
Found a good YouTube video of a guy using the tool and the carbon cleaner on his '15 FXT, should come in very handy when I go through the process. Looks easy enough, but I'm the guy who had a major struggle changing his rear sway bar...I still got that done and I'll get the cleaning done, too.
 
#35 ·
I've been thinking about doing this in the next 5K miles or so (am currently around 21K miles), but despite doing some of my own maintenance (engine oil, all filters, tire rotations, diffs, etc.), I'm a little apprehensive to try this. To be honest, I don't know how to tell which hoses are vacuum...

I watched the previously mentioned video on YouTube, and it shows some detail, but I'm still not 100% sure which one to use.

Has anyone seen this video:



It's on a WRX, and a different product (CRC Intake Cleaner), but it seems like he's trying to achieve the same results (reduce carbon deposits). Instead of finding a hose to disconnect, he uses the MAP sensor port. Could that be used with the Top Engine Cleaning Tool (SOA868V9430) and Subaru Carbon Clean (SOA868V9165)?

Also, am I correct in assuming that this service should be performed just prior to an engine oil change?
 
#40 ·
Taking The Bait - Carbon Clean - SOA868V9430

Ok, I'm game. I'm going to order the kit.

I hope the cleaning action doesn't leave some hard carbon chips to damage my turbo's exhaust impeller or clog the catalytic converter mesh.
--> Any thoughts?
--> I wonder if Danoz or Last Human's Garage are using this stuff. Those fellows are both pretty well read & researched.

I ordered from Heuberger in Colorado.
I order both Carbon Clean & Top ENgine Clean. IDK the diff. But I 'll read the ingredients when I get it.

Here is what I ordered:

SOA868V9430 Top Engine Tools (the metering device & flow tubes)
soa868v9165 Carbon Clean solution
soa868v9160 Top Engine Cleaner solution

BTW, is there a walnut blasting service thread?

Thanks.
 
You have insufficient privileges to reply here.
Top