Throttle body needs cleaning

[Jeremy Owen]

I get my NB serviced at Mazda and every once in a while they say I need the throttle body cleaned out. I once asked if this was normal and it was suggested that I might have had a bad batch of fuel, but I know this to be completely impossible because I always pay the premium for Shell Optimax.

My question is; does driving style, or rather right-foot style, have any bearing on how dirty the throttle body gets? Or is it just my wallet which is getting cleaned out?

[bruce]

They'll probably squirt a can of crap into your inlet and charge you a hundred bucks.

[GP]

Makes sense, Optimax is crap fuel

[Jeremy Owen]

Ok, new topic; what is the best fuel to use? - assuming I want to be able to drive up to a regular bowser and not be mixing up things in my lounge room.

[bruce]

That is a COW (controversial question).

[two40]

Makes sense, Optimax is crap fuel

Most fuels are fine as long as you are buying it from a busy servo so that you get fresh fuel. Also try to avoid draining your tank to near empty as you can pick up dirt from the bottom of the tank. This mostly applies to old cars though. Most likely as you suspected they are cleaning out your wallet. It should not need to be done regularly.

Use Synergy, Optimax or Ultimate from a busy servo and you should be fine. Also try to stick to one. Just pick your most local one or a servo that you will most likely drive past every week or whatever.

People that tell you X fuel is crap have usually had a bad experience (bad batches do happen and all the suppliers are prone to them). Either that or they're just repeating what they read on some forum from someone else that's repeating and so on.

There is no best fuel.

[de Bounce]

Unless I missing something
It should make stuff all difference what fuel is used or where it was purchased from.

How is the fuel diverted, against the direction of air flow, from the injector, through the inlet port, back through the plenum to make the throttle body dirty!

Sounds like a money grab

IMHO
If you want to check if it needs cleaning. remove the air inlet pipe at the throttle body (one hose clamp) and look in, its gonna be a little dirty from the oil from the PCV valve, but unless its full of crap and affecting the operation of the throttle, leave it alone.

Makes sense, Optimax is crap fuel

Most fuels are fine as long as you are buying it from a busy servo so that you get fresh fuel. Also try to avoid draining your tank to near empty as you can pick up dirt from the bottom of the tank. This mostly applies to old cars though. Most likely as you suspected they are cleaning out your wallet. It should not need to be done regularly.

Use Synergy, Optimax or Ultimate from a busy servo and you should be fine. Also try to stick to one. Just pick your most local one or a servo that you will most likely drive past every week or whatever.

People that tell you X fuel is crap have usually had a bad experience (bad batches do happen and all the suppliers are prone to them). Either that or they're just repeating what they read on some forum from someone else that's repeating and so on.

There is no best fuel.

X2

[Steampunk]

How is the fuel diverted, against the direction of air flow, from the injector, through the inlet port, back through the plenum to make the throttle body dirty!

Sounds like a money grab

I agree.
Jeremy, you didn't actually state what symptoms you have. Hesitation? loss of power?

[bigdog]

Fuel doesn't flow thru the throttle body, air does. The air will contain a component of oil blow by circulated from the rocker cover into the inlet manifold via the PCV valve, plus any contaminants that get past the air filter. Removing the TB and cleaning it is easy enough to be done semi regularly (every couple of years should do it).

[madboy]

isn't this what that Subaru upper engine carbon cleaner stuff is for?

The TB seems like a very small part of the intake system that they targeted it for a clean...sounds like a money grab to me.

MB

[Russellb]

isn't this what that Subaru upper engine carbon cleaner stuff is for?

The TB seems like a very small part of the intake system that they targeted it for a clean...sounds like a money grab to me.

MB

The Subaru UPPER CYLINDER CLEANER has a foaming property that dissolves carbon build up
in the manifold and the engine
this reducse the Cylinder temp and stops pinging ( deternation )
have seen 10 ish + KW on the dyno from using it

Great stuff well worth the money

[green_comet]

Fuel doesn't flow thru the throttle body, air does. The air will contain a component of oil blow by circulated from the rocker cover into the inlet manifold via the PCV valve, plus any contaminants that get past the air filter. Removing the TB and cleaning it is easy enough to be done semi regularly (every couple of years should do it).

Thanks for this post Bigdog, I was shaking my head though every post until I got to this one.


Cleaning the throttle body is easy, go get a can of subaru upper engine cleaner, a can of throttle body cleaner, and get spraying. It takes about 5min to pull your throttle body out, and about 10 min to clean it. The Subaru upper engine cleaner is used to clean all the sh*t out of your intake manifold, and this takes about 15min to do.

[de Bounce]

The Subaru Cleaner has been discussed
Here

Might be worth noting the following points from the thread:
Makes a heap of smoke when being used
Do it just before an oil change

[Alex]

If yours is anything like mine it's just a thin later of oily residue I think this is a common issue for most NB's mine has it as well (with <60k km) but I never noticed until I installed an intake and took a look.
Also the piping on the intake I had was quite dirty when I got it probably due to the filter used and the rocker cover outlet, I cleaned it up got a good filter and never had to look at it again.

I don't think my car has any adverse affects to having a dirty throttle body but next service it'll probably get the subaru cleaner put through it anyway.

[Jeremy Owen]

Thanks for all the info. I'll decline their offer to clean it next time and have a look myself. I must say, that everything feels tighter and more responsive after a service, so they are doing some good. (I am the type of guy who puts petrol in the little hole in the side, keep the tyres inflated, and anything else I let the professionals do )