AVCS solenoid cleaning and oil feed banjo bolt filter clean

Anyone ever do either of these? I have read it can cause the solenoids to stick and not function properly which can cause rough idle and unsmooth acceleration. Something about the AVCS filter becoming clogged can affect its performance. I think mine has dual AVCS so does that mean there is 4 solenoids to look at? intake and exhaust on both heads? i think i have located 3 of them. need to go fishing for the fourth one!

Anyone ever here of the Subaru upper cylinder cleaner? Seems like its a common thing to get used by the US and OZ subaru owners.


Engine power output is created by the burning of fuel in a vehicle's cylinders. As petrol is a hydrocarbon fuel, made up of hydrogen and carbon, after combustion it leaves carbon as a by-product or deposit. Over a relatively short period of time the carbon deposits on the walls of the combustion chamber, the piston crown (top surface), and on the valves, can result in the deterioration of engine efficiency. This may lead to poor fuel economy, reduced power and harder starting.
To overcome this situation, the factory has formulated ‘Upper Engine Cleaner (SA459)’, which is a concentrated combustion chamber and induction system cleaner. This product helps clean and purge gum, varnish, and carbon deposits. Using this solvent during scheduled servicing has proven to be a valuable form of preventative maintenance.

If your vehicle were subjected to regular stop/start driving, short trips, or poor fuel quality, the build up of gum, varnish, and carbon deposits would be far more rapid. In addition to ‘Upper Engine Cleaner (SA459)’, we suggest the use of ‘SA718 Fuel Additive’ to maximise your engine’s protection against such concerns.

Both products have been specially formulated by Fuji Heavy Industries, the manufacturer of your Subaru vehicle, to be compatible with the Subaru horizontally opposed engine and it’s technically advanced electronics. These products are available through all authorised Subaru Dealers.

i am not a mechanic so dont know
but isn't this seafoam
never tried it myself but think it is something for high mileage cars
dont think your car needs it
especially since your car is not standard and has changed spec would be something i personally would be cautious of
if it aint broke dont fix it
again i am not a mechanic but personally i would not pour that stuff down my own car unless i was having issues with my top engine / intercooler being full of sh*te wich hopefully will never happen
just my 2 cents

there was a lad in uk with same mods as mine and mapper discovered that the left side OCV on the exhaust AVCS was advancing and retarding abnormally and supposedly quite common on Subaru's. I might take the solenoids off and give them a cleaning first and see if that helps. He was having shuddering issues on cold starts like me

i think it can do damage to a car so it needs to be done bye a mechanic
i wouldnt do it
dont mind what you read online
ask ken-c
id say he will know
or a trader
i wouldnt be pissing in the wind on a setup like yours
be a expensive lesson if turns out wrong
[quote author=Altezza-Dan link=topic=32456.msg371848#msg371848 date=1322943293]
there was a lad in uk with same mods as mine and mapper discovered that the left side OCV on the exhaust AVCS was advancing and retarding abnormally and supposedly quite common on Subaru's. I might take the solenoids off and give them a cleaning first and see if that helps. He was having shuddering issues on cold starts like me
[/quote]

[quote author=scoobycolm link=topic=32456.msg371850#msg371850 date=1322943693]
i think it can do damage to a car so it needs to be done bye a mechanic
i wouldnt do it
dont mind what you read online
ask ken-c
id say he will know
or a trader
i wouldnt be pissing in the wind on a setup like yours
be a expensive lesson if turns out wrong
[quote author=Altezza-Dan link=topic=32456.msg371848#msg371848 date=1322943293]
there was a lad in uk with same mods as mine and mapper discovered that the left side OCV on the exhaust AVCS was advancing and retarding abnormally and supposedly quite common on Subaru's. I might take the solenoids off and give them a cleaning first and see if that helps. He was having shuddering issues on cold starts like me
[/quote]
[/quote]

I'm just talking about cleaning the solenoids Colm. There is screen filters inline that can get blocked up so will check them and solenoids and plugs

shouldnt be a problem so
tought you where going to pour it in to the intercooler and see what happened
dont mind me so

No no! Ill see if Cadillac and Roche sell that stuff. If not I won't bother with it!

Just noticed this thread now.

Did you get anywhere with these inspection/cleaning jobs Dan?

I've been trying to find location of the banjo bolt myself and can't find it for the life of me - at the moment the intercooler and turbo shield is off and still can't see it - might not be on mine since turbo is non standard but anyway... anyone manage to locate/clean this turbo oil line filter?

Regarding AVCS solenoids - i will be inspecting these to when i get a chance - i think i only have two of them in the 03 Blob - if they were stuck/dirty yes it would cause drivability/idling problems. I've just cleaned my IACV but not put engine back so don't know if performance will improve yet.

About the Subaru engine top down cleaner - i asked C&R about it before and even though it is an official Subaru product he said they can't get it into the country (probably for stupid export of hazardous materials reasons - same as why you can't get certain oil/grease products from US ebay). They do a top down cleaning service in C&R which involves running a special bottle of cleaner through fuel system (after disconecting fuel system) and burning it in engine for nearly an hour - I was thinking of getting this done - it's €100 at least though.

everything was cleaned out during the re-build!

I'm having trouble with this IACV. Moving this to new thread...