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