Procedure for throttle body cleaning on 88 300e
 

Hi Everyone,

I'd like to do a thorough cleaning on the throttle body on my 88 330e,
but it seem like a real labour and a half to get to. I'm sure someone
has done this, so I would apprciate any info on procedures,
required tools and cautions.

I did do a search but I was only able to get some general info only.

Thanks in advance,

bluebenz,

:)

are you
 

are you talking about the intake...

when you say throtle body...
:D

WHY do you want to clean the throttle body? I have yet to note anyone finding a reason to need to do this. Much more likely to need to clean the airflow meter, idle control valve, and replace the idle air circuit hoses. Once you have those off, well, the throttle body is now exposed, if so inclined.

Steve

Because its dirty Steve.

A dirty throttle body can cause problems with idle since the dirt
can cause the throttle body to stick even if you have a clean
AF meter, ICV, and sound idle air circuit hoses.

Air flow meter and throttle body are the same thing.

Uhm!! NO! The Air Flow Meter sits above the Throttle Plate and Throttle Body! Two seperate devices and flaps! You have to remove the AFM to access the Throttle Body properly but it can be cleaned by holding down the AFM Plate and spraying liberal amounts of cleaner down in there.

Point is, how do you KNOW it's dirty? I've cleaned many throttle bodies in other brands where clogged idle bypass circuits and other complexities are easily affected. Your throttle body has none of that - just externally accessible wear/lube components. You can't see it without removing all the much more vulnerable hardware, so if the throttle body needs cleaning, you can be sure the airflow meter and is a mess. THAT you can see, inspect, perform some cleaning, and decide if you need to dig deeper just by removing the air cleaner housing.

Steve

i own this car
 

I own this car but I dont know what you guys are talking about..

the intake is what connects to the head and it will be full of sut and the fuel injectors sit up against the head... so clean the fuel injectors.... Now the intake has quite large air passages and they lead to the air flow sensor so I would clean the air flow sensor... on top on the intake is the fuel distributor you might want to clean that.... but I would leave the intake alone...

dissambling and reassembling that intake would be worse than doing the head... and I just had a car fire there no fun... So if I were you I would get some gunk and just clean the exterior.... :D

The throttle body sits below the airflow sensor module - its butterfly valve is what is actuated mechanically by pressing down and releasing the accelerator. It sits on top of the intake manifold's plenum, before the air separates to the intake runners.

Steve

i think
 

ok i understand what your talking about... but i think the
think that is most important is the baffel in the air flow sensor..

I think it gets lodged open or closed and the air flow sensor fails
causing check engine light... and expensive repair....

the only thing I have ever heard recommended to be cleaned is the
fuel injectors and the air flow sensor...

Well Steve, it's a little trick I do with my eyes. I just of point them
in the direction of what I want to see and the light rays reflecting off
the intended target get interpreted by the brain via the optic
nerve. Actually, I think it works that way for pretty much everybody.

But more specifically, I moved the butterfly valve down and managed
to shine a small light in on the throttle body. It had a significant amount of
dirt on it. To confirm, I swabed the Throttle Body with a q-tip.
That is how I know the throttle body is dirty.
I've had other vehicles where this has caused problems
(not discounting the items mentioned before). So I thought a cleaning
would be a good preventative measure along with the other items you mentioned.

Throttle Body Cleaner! Spray it in the AFM with the engine running and holding the throttle open so the engine stays running. DO this with plenty of ventalation. I empty about half a can in there. Then I shut her down and spray liberally into the AFM holding the plate open. Then I open the Throttle via the throttle mechanism! Then start and run. It will not start right up after this since there will be a ton of cleaner in there.

Thanks Jamie.

:)

No problem!:D

Hello bluebenz,

I did it on my 260 E, 1988, 400 000km, I agree there is a need for cleaning it.

Long milage and riding in cities at very low speed makes vapor oil to condense in the body and prevent idle opening to remain correct.

I just had to remove the assembly distributor+ air flow sensor (all together, no need to dissamble them) and cleaned it with good cleaner (I changed the gasket and the 2 small connectors for the vaccum lines).

Take the opportunity to clean also the three small holes for the vaccum lines.

Do not change the setting of the flap stop screw (what I did unfortunately and never found the method to adjust it except by trial and error). I opened a thread on the matter and posted pictures.

Would you do it, could you please post pictures of the inner side to show the position of the flap versus the two holes when closed ie at idle.

Good luck.