Cleaning throttle body

[lordluvitt]

Following on from my thread regarding a misfire/backfire/rev problem, I removed the air filter body from my 1998 W202 C180 to find that the top of my throttle body where the flap is was caked in gunk. So too was the short hose from the top of the crankcase into the air duct.

My experiences in the past with aircooled engines suggests that this creamy gunk is water in the oil caused by condensation not burning off during engine running (I only commute 7 miles to work so the engine wouldn't reach full temperature to burn off condensation).

In the past I have sprayed carb cleaner or redex directly into the throttle body to clean the system. However, is this method possible with an injection system?

 

[English Teacher]

If your engine is not using water via the header tank, then condensation sounds possible for your gunk. However, I would have thought seven miles would be enough to drive this off. Removal of the throttle body should be quite simple, allowing cleaning without pushing the contaminants further into the engine. I would think SPRAYING redex or similar into the throttle body would be ok (although of limited effectiveness) as long as there was not sufficient quantity which could be sucked into an engine cylinder, causing the incompressable liquid to damage the engine. You might want to check your engine oil spec and change your oil.

 

[lordluvitt]

Hi. Thanks for the response.

My water system does have the header tank over the radiator and my last oil change (about 4-5k miles ago) was at the service (MB centre) and I understand they used the correct Mobil 1 oil. I guess I may have to flush the engine and refill to clear it all.

I was just considering cleaning the throttle with it still attached to the car but it would seem better really to take it all out, along with the injectors, and clean the whole system on the bench. Don't want to be damaging the engine if there is any risk by pouring Redex down the throttle!