Hello all sifu's

I notice nowadays that a lot of problems with current cars especially those with the local makes have problems with throttle bodies, getting dirty and so on. Is it mainly because of the petrol, design problem of the TB, the air or what. and how often do you clean your TB's ? I suspect its the type of petrol. Correct me if I'm wrong.


Many thanks guys.

dirty because normally engine breather directly plug back to intake system

its engine oil not petrol....

to avoid this problem... unplug engine breather from intake system + oil catch tank..

at intake system there.. just use stopper to close opened valve/pipe

Man, this is rocket science to me

Thanks, I'd better leave this to the SC

biasalah kaki kuat
even carb olso get dirty
my carb air filter got brown oil stain
all the gum , vapor , dirt from theoil pan when the engine is running hot get suck at the mainifold because of the pcv valve ma
if u always push the car so get dirty faster lo

Air is dirty in the first place. Some cars will not even start if TB is stuck or very dirty.

normally nowadays many fresh grads mechanic is sc due to cut cost n many of them always over filled d engine oil which causes dirty TB~

yala... overfill with engine oil makes the car heavier to drive also...

Wow...didn;t know that overfilling engine oil can also cause TB clogging up

hehe how to clean for campro..hehe

One way to prevent TB dirty is to do a PCV by-pass. U will notice 2 hoses coming from the intake manifold and cam cover, correct?

Surely this will affect the performance somehow, wouldn';t it?

Nope. Did this simple mod for all my smart since Day 1. TB only dirty after 2 years of usage. If not, have to service TB every year.

Its the air filter element. Most people does not change it, just blow clean it. Slowly the material deteriorate and allow dust and what not into the throttle body, mix with PVC oil that is coming up during high rev or over filled engine oil........ you get a very dirty TB.

by pass? to where?
oil catch tank?

On the engine, u will notice 2 hoses coming from cam cover and intake manifold.

U need to T both hoses together and connect to an oil catch tank (if not, dump to ground).

Refer below:



Notice the top brown hose and bottom clear hose? Previously the bottom hose was connected on the cam cover. Now, with a simple mod, u T the hoses (cam cover has 2 outlets) together and dump to either an oil catch tank or ground. Refer to 2nd image below.



Remember the bottom clear hose? It now goes to the intake pipe after the filter where the 2nd cam cover outlet used to be. Some people say better performance as intake manifold will be able to suck cleaner air directly bypassing the TB. Some say higher FC after that (in my case, yes... higher FC). If u not confident, simply cap both ends with rubber cap (a must or car may stall due to vacuum leak).

This post has been edited by acbc: Jan 16 2011, 01:15 PM

Lol...thx for the info abc...not too sure I'll do this to my new car

Actually, both hoses used to be transparent and they turn brown after 2 years of light usage. It shows that manufacturers chose to reroute dirty oil vapour into the intake manifold and intake pipe which will eventually clogged the TB. This is very bad for those with electronic TB (cars that have drive by wire such as Gen2 and Vios).

That would include my old Wira

lol, only new car mostly hv throttle drive by wire ler.. any wira model still use cable for throttle-ling

LOL in case, my old Wira still had problems with throttle body

errr
dont have any intention to flame ppl
but car manufactor reroute the oil vapor to intake manifold due to the emission and enviromental issue
in old day the oil vapour are release to open air but this were demed to dirty thus later they plug to manifold and it suck to the combustion chamber and were combust away
trade of it is gum,oil residue were left on the whole intake system lo

Correction, for environmental and money making process. By clogging the TB, u will have to pay for replacement fast. Good for service centre.

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Added on January 20, 2011, 2:31 pmThat one is a problem inherited from Mitsubishi. Till now, they never figure how to improve it. Many mechanics resort to cut and paste parts from Toyota to solve this nagging issue.

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Added on January 20, 2011, 2:32 pmSame goes for Myvi. All driven by throttle cable. Good and bad.

This post has been edited by acbc: Jan 20 2011, 02:32 PM

So is that to say that Toyota cars are more resilient to dirty throttle bodies by virtue of their design and parts?

TS, Can you tell us what are the "Current Cars" you talking about?

During combustion some of the fuel may travel backup to the valves, this may include the throttle body valve, when the engine cools down, these fuel harden and sticks on the valve & body, becomes carbon. As such you get buildups. And since only air travels tru the body, there's no cleansing agent, as such the clogs remains there and builds up more & more til one day you have insufficient air and affects the car performance.

Not sure about old cars because they use carburetor have air & fuel mixed inside as such cleansing agent added into the petrol tank will wash some of the deposits away.

For Direct Injection Engines, these problems are much worse, e.g. newer Audi, Lexus, Volkswagen engines, as they utilize Direct injection, fuel don't even passtru the air intake valve, as such the air intake valve which directly connect to the combustion chamber will suffer more of this problem, since it's next to the combustion chamber, the force is higher and fuel will backflow to the air intake valve faster than Throttle body, and more severe clogging happens on those engines, and since air intake valves are smaller than Throttle body valves, the effect is much worse for DI Engines. Cleaning the valve every 20k km is normal as they build up much faster than non direct injected engines.

all think until so complicated for what??.. its the air filter not filtering the air 100% efficiently laa... surely there will be some dust passing through it at high revs....

If Dirty Air goes in it'd go straight into the combustion chamber, it may stay inside the chamber but it won't stuck in the throttle body like gum and end up getting bigger & bigger becoming deposits will they. Unless it's oily air getting in.

No. I'm saying Toyota have better tech in solving this aging old infections Mitsubishi problem.

This post has been edited by acbc: Jan 21 2011, 09:29 PM

Aiya use carb la no fancy stuff so no headache but no fancy fc and no fancy refinement lo . No free lunch in this world

If u don't want to worry about TB issues, buy a diesel. Even carb have TB issues also just lesser.