autojava

Hi, Guys:

With the Haynes book at hand, I try to change the coolant by
myself. My car is 2006 C280 with 3.0 engine. After open
the hood, I can not find the radiator cap (while the book shows
that it has in picture 26.10).
I hope to get clarification from this board:
1): 2006 C280 does NOT have raditor cap? or where it is?
2): When change the coolant, after drained, does it add
the coolant at expansion tank, instead of radiator cap? (as other car does).

Thanks.

VVF

Yes, drain from the bottom radiator plug, fill at the expansion tank.

Then start the car and wait till all the bubbles are gone.
You may also want to squeeze the coolant hoses a couple times to speed up the process.
Refer to the manual as to the specific air bleeding process.

autojava

Hi, VVF:

"Yes, drain from the bottom radiator plug, fill at the expansion tank.",
then when drained, the expansion tank should become empty.
and when added, the fluid should get into radiator from the expansion tank.
But I believe that there should a control valve between tank and radiator?
How this control value work when adding fluid?

VVF

I am assuming you found out about the control valve from the service manual?
Then surely it has the procedures to deal with that?

I do not see anything specific about coolant drain/fill for M272 engine in WIS.
It tells to use a special tool for vacuum bleeding, but that's not M272-specific.

autojava

Hi, VVF:

Any idea or advice about
1): the location of engine block drain plug and
2): easy/difficult to access the plug? or
3): whether or not worth to drain the coolant inside the engine block?

Thanks.

VVF

I will be able to look it up on Sunday maybe.

When I changed coolant in my car, I did not bother with the engine drain plug.
I drained the radiator, then filled with distilled water, started the car and ran it until it reached operating temp. Then heater on high, revved a little till warm air started blowing from the vents, then after ~5 mins shut the car, drained, and repeated this 3 times.
That way you will only have distilled water left in the system, plus you have flushed the heater core etc.
Then just look in your user manual as to what amount of undiluted coolant must be in the system, add that amount, and top off with water. (Or make a pre-dulited mixture but subtract the amount of water left in the system since you are not draining the block)

Good luck