Raj12121

Hi everyone, recently bought a 2010 c250 blueefficiency cgi (w204). 78k miles.

Recently have noticed white smoke from the exhaust on start up but the smoke persists throughout the drive once the engine is warmed up and it doesn't overheat. Had the low coolant sign pop up 2 weeks ago to fill the coolant which I did.

Since then, have still noticed the white smoke and am continually checking if the coolant levels are dropping. (no sign as of yet)

Have attached a few pictures below of what looks to be coolant dried up around a specific part which I'm unsure what it is. Would this cause white smoke somehow from the exhaust? In one of the pictures, coolant looks freshly leaked. Unsure if it is coolant or if glue was used to prop the pipe in. Taking to a garage over the weekend, but just wanted an idea if anyone would know. Thanks.

Car runs fine, besides a slight judder from the car when pressing the accelerator around 40mph. Car noticeably judders where I have to let go of the accelerator and press it again, then it speeds up fine. This has happened maybe 4 times in 6 months.

Any information would be great. Thanks.

TimC300

Not familiar with that engine but to me it looks like maybe the o-ring at that connection is leaking and needs replacing. I know in my car they sell just the replacement o-rings instead of buying the entire hose. Looks like its connected to the heater water pump. Maybe someone knows the name or part number of the plastic hose thats leaking. I dont see that causing white smoke out the exhaust.


Heater pump coolant valve?

gamma300C

I would suggest a quick check for antifreeze/coolant presence in oil...ACUSTRIP 711254 Series or similar products are an easy, fairly cheap method to rule out cross contamination. Your leaking fittings are a good find for repair needs but ,as mentioned above, won't make for white smoke out the tailpipe(s). Small amounts of H20 will give fairly visual white exhaust..overnight condensation in exhaust can do in this on start up and for several minutes til burn off so the coolant level in your reservoir can take it's time dropping.

TimC300

What color was the coolant you put in to top it off? Was it red, that same color as the residue on the coolant pipes? I ask because you said you're wondering if that residue may be glue.

I searched and searched but cannot seem to find the part number for that plastic hose or see if there is an o-ring in there.. I can find diagrams but no part #.