Intake cleaning spray thread

[Greg Roles]

Hey all,

As I get a LOT of questions related to PCV and catch cans, thought I'd start a thread to hear peoples experiences and techniques of using intake cleaning sprays. I'm aware of a few different brands, but have recently been recommending the "Subaru upper engine cleaner" SA459, an aerosol spray. This needs to be added after the air cleaner element, and to be safe, alongside / after the MAF as they can be sensitive. I need to find out if this stuff is MAF safe. That said it does take a bit to kill a MAF, but what I am trying to do here is amass all the information, as I'm no absolute expert on this stuff.

From a Subaru website:

Half a can is sprayed it then wait 10 minutes. Then the vehicle is started & whilst idling (juggling the throttle cables) the remainder of the can is sprayed into the inlet & the engine is turned off. Wait another 10 minutes, then restart the engine & rev it to 4000+ revs till the smoke from the exhaust clears. ( I'd suggest on a warm engine!! )


It will smoke a LOT, and make sure your exhaust is facing somewhere it doesn't matter, as a lot of black crud will end up on the ground behind the car, could really spoil a nice garage! In a normal petrol car, the car will struggle to run on it, will need a bit of throttle to clear it all. A diesel is ENTIRELY different, and this stuff will act as a fuel and make it rev right out. In a diesel you need to slowly add it whilst idling, and I mean slowly, as easch squirt is like opening the throttle, or best idea is to make up an intake restrictor plate, so that the intake is reduced down to a hole the size of a 5-10cent piece, thus preventing max revs as the spray is added. I also found a picture of the LiquidMoly product used by Ramspeed on the diesels - I am researching diesel specific products at the moment, but all the usual Subaru, Seafoam etc etc are not really suitable, as the diesles will throttle up on them.




In no whay whatsoever would I recommend using this or any oil removing spray on a DPF equipped diesel, as it will all end up in your DPF, and oil ash cannot be regenerated or burnt off. You DPF types need to be running a Provent from new, and consider methods to reduce the EGR introduced. For the time being that's all you can do.

Be interested to hear and see what people have done, and especially pictures of where you added the spray along the intake on the various models. Also love to hear of other brands such as Wynns who have similar products.

[Transporter]

My experience is, that unless you do it at every oil change, these spray cans will clean only around the throttle flap and bit around the intake valves, that's it, especially on the diesels where the oil with soot get glued to the intake inside walls. Removing the intake and installing Provent200 is only way reduce the oil buld up and your intake flaps from early failure costing you around $1000 just in the parts to fix on the 4 cyl. VAG car.

So, if you do it, do it at every oil change, these spray cans are cheap.

[Greg Roles]

[Greg Roles]

The professional system I know Miro ( Transporter ) has - I might have to invest in one down the line!

Long video.....

[Transporter]

Yes, I know Frank.
However the diesels with the DPF, I'm still removing the intakes for the manual clean. Though, I use BG Diesel ISC on t/body parts during the cleaning. The TSI engines are no worries.

The BG system is good, much better than spray cans. The fuel tank additive for diesel 244K and 44K for petrol are the best I ever used. Highly recommend.

[ForceFed]

244k is awesome.

[Bug_racer]

My personal opinion on both catch cans and intake spray is they dont do much and its a waste of money .
Injectors need to be cleaned , dividers in the head need to be cleaned , intake manifold flaps need to be cleaned , throttle body needs to be cleaned . Spray a can of degreaser/petrol/kero based cleaner isnt going to do much to remove baked on carbon in the intake .
It takes me days to do it properly manually and leaves a polished valve finish equivalent to acid dipping the head . Thats the finish you need to restore back the performance of the car .

[Greg Roles]

Interesting that you see the immense problem of blowby / EGR first hand yet don't support catch cans that are there to try and decrease it. I agree most catch cans do jack s#@t as they are just empty cans. I may sell em and thus seem biased, but catch cans is one thing I very much believe in, and the sheer demand for them supports my thinking. I do agree removing baked on carbon via a spray isn't going to happen, hence the need for blowby reduction from new.

[Transporter]

The Provent200 works (as well as some other catch cans), it reduces the oil in the intake greatly. Cleaning the intake works too, but you should do it every 30,000km otherwise it will not remove the thick layer in one hit.

Definitely not waste of money, petrol or diesel, you will notice the difference and the engine benefits from it, you get some power restored and the fuel economy improved as the results from it. It has potential to save hundreds and hundreds of dollars, because the intake flap and EGR valve in the t/body will last longer and not die on you.

It's all part of the maintenance I recommend to my customers.


"obsessed is how the lazy describe the dedicated"

[Ben J]

I ran a can of that Subaru upper engine cleaner through my little 1.8 and it definitely helped a little bit, no doubt it wouldn't have done nearly as much as fully pulling everything apart and cleaning it properly, but it helped a bit for sure, engine runs a bit smoother and feels a little more responsive. For the like $12 dollars it cost and twenty minutes to do, I'd say it was very worthwhile while doing a bit of a service.

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