this is somewhat related to cerbo's post on dfi engines. POrt injection cleans the valves and prevents the dreaded carbon buildup so many talk about on dfi engines. will additives like the 3M intake cleaner work? this is fed through the intake system and not through the fuel system. engine cleaners like this in theory will reach the valves as the introduction is through the end of the intake ports. additives introduced through the fuel will likely not do any help in carbon build up on the valves,
are there any reports on the effectivity of these types of cleaners. i only know of the 3m cleaner.
i am thinking it should work.
our experts care to comment?

 

While it is true the fuel injector injects fuel directly into the combustion chamber and the fuel spray does not directly contact the back of the intake valves, under some conditions the vapor cloud of fuel and air can make it part of the way into the intake ports and thus the back of the valves are in contact with the fuel and its additives.


Thus for the valves to develop a build up of deposits combustion (and pre-combustion) gases must be in contact with the valve surfaces. Admittedly this vapor cloud and combustion gases are not the only source of intake valve deposits. Crankcase fumes routed to the intake contribute to this.


But because the vapor cloud and combustion gases do make contact with the valve surfaces one can add to the gasoline's additive/detergent package by using Techron.


If one runs Techron in the fuel this Techron contacts the valve surfaces and helps remove deposits.


Even though the Techron goes through combustion there is a portion of it that is intended to resist combustion, though it turns into vapor in the heat of combustion.


But when this vapor comes into contact with cooler surfaces, it reverts to liquid and helps clean the valve surfaces.


The question is whether it is necessary to use Techron?


I still say the best way to keep the engine free of deposits is to drive the car and drive it enough and in a way the premium fuel can clean the valves and other surfaces.


Premium fuel has detergents that do the same thing as Techron, and of course come gasoline comes with Techron already present as an additive though not probably as large a dose as one obtains by adding Techron. (Word is the stuff out of the bottle is very concentrated.)


It also would help that the driving exercise the engine more than is the norm for some drivers. This putting around town helps load up the valves with deposits but does not much if anything towards removing the deposits.


At higher loads, higher RPMs, with more heat, this works to clean the valves. No need to get all crazy with the car. I have often noted that the engines of my cars really perk up after a highway drive of 40 or more miles.


If you believe Techron is called for follow the directions on the bottle. After you run the last tank with Techron added down to say 1/4 or thereabouts, ideally you should change the oil/filter.


Techron can add to the oil's contamination and these engines do not need any extra oil contamination.

 

Hi mac, i see your an advocate of techron. I do use it too, but my current thought, with dfi engines, that techron would be less effective due to the dfi setup. Port injection...no worries. Now, there are cleaners that we do not mix with the fuel but rather introduce through the intake before the throttle valve. In theory, they should work better. Question is do they? I actually have the 3m intake cleaner and have not used it yet. Anothe rqueetion is with these type of cleaners, do we need oil change?

 

Primarily I'm an advocate of keeping the engine clean naturally.

Techron has its place, but having to use it is an admission the owner is just not doing as much as he could for his engine's hygiene to keep the engine clean naturally.

The engine should be self cleaning if given half a chance.

Unfortunately this means driving the car. (I'm being ironic for it seems many owners apparently do not want to drive their Porsches.)

As I have mentioned more than once after a 40+ mile highway jaunt the engine is my car (and this has been the case for my Boxster, my Turbo and other non-Porsche cars I have owned) the engine perks up considerably.

I attribute this to a bit of cleaning taking place during the drive. Premium gasoline has a goodly amount of detergents in it that are intended to keep the fuel system and engine free of deposits.

But the engine needs to be given some time for these detergents to work. Stop/start driving just doesn't result in enough real engine use, the engine doesn't get any real work out, to effect a real engine cleaning.

The engine needs to run at something above idle and for an extended period of time.

How much time?

My work commute is 30 miles which consists of about 28.5 miles of freeway driving. Even if I make this drive at times there is no traffic and thus can sustain 65 to 75mph speeds for the entire freeway duration of the trip is not enough. I notice no change in the engine's "perkiness".

Based on my experience, a longer drive of 40+ miles is needed. Furthermore, based on my experience during this drive one doesn't have to drive the car like he stole it. Many times I have left my house and once on the freeway set the cruise control to say 70mph (the limit is 65mph) and driven the entire 40+ miles at a steady 70mph. Given the route even if I wanted to drive the car like I stole it I couldn't, not safely at any rate.

I have problems with cleaners introduced to the engine via the intake system.

Ignoring the amount of actual cleaning that can be done with probably cold fluid and a cold engine there is the concern about compromising, if only temporarily, the lubrication between the piston/rings and cylinder wall.

There is also the concern about contaminating the engine oil, though this can be dealt with a post cleaning oil/filter service.

Really the only thing that should go through the intake is filtered air.

If one can't or won't drive the car enough to help keep the engine clean then Techron can be used. It bolsters the detergent additive package of the gasoline with the idea (and hope) that this will effect a suitable cleaning without requiring the driver to bear the pain and agony of having to take a 40+ mile drive in his Porsche. (Irony.)

While Techron probably can effect a cleaning of the engine this is not without some concern.

There is the concern about oil contamination. However, this can dealt with satisfactorily by an oil/filter service.

But there is the concern about the deposits that have built up and which are removed. Techron out the bottle is rumored to be (I may have some link to some official source of info on the strength of Techron) a pretty aggressive detergent. Out of the bottle it is in concentrated form though of course diluted with IIRC 10 gallons of gasoline.

While Techron removes the deposits whenever a deposit is removed it can pluck or take with it some of the base metal to which the deposit was attached to.

Losing metal from the piston crown or combustion chamber surfaces is of no real concern.

But the erosion that for instance the fuel injector tips experience is some cause for concern. Fuel injectors can last a long time -- example: My 02 Boxster with its original injectors with over 283K miles on them -- but too much Techron could shorten their life.

'course, an engine with heavy deposits is not a good thing either and if the trade off is possibly shorter injector life vs. living with an engine with heavy deposits which will after a point effect engine performance (drivability) I would elect to use Techron and risk shorter injector life.

I mean if it was just too much to ask of me to drive my Porsche more. (Irony again.)