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S580e W223 Clicking Noise from Coolant Valve – Common Issue? New Valve Didn’t Fix It
Hi everyone,
I’m experiencing an issue with my Mercedes S580e (W223) and I’m trying to see if others have the same problem.
There is a loud, repetitive clicking / knocking noise coming from the engine bay area, especially when the engine is warm and the climate control system is active (it seems more noticeable when the rear climate is turned on).
I can confirm that the noise is definitely coming from the coolant/heater control valve. The valve has already been replaced with a brand new original Mercedes part, but the noise is still present and unchanged.
The sound suggests that something is constantly actuating or struggling to regulate flow, which doesn’t seem normal for a car in this class.
I’ve seen a few reports suggesting that many vehicles with the same model might have this issue.
Has anyone else experienced this?
Is there a known fix (software update, bleeding procedure, or another component involved)?
I thought you were posting on a wrong forum, should have been W123 (W124) . I didn't know they had reintroduced those solenoid valves. In any case, on a modern Mercedes heating should not be controlled by heating water temperature but air flow flaps instead (unlike W124 etc.). I cannot see why those valves would pulse frequently.
The noise did not appear very strong on your video, perhaps stronger for the ear. How should I test it, can you hear it in the cabin or do you have to listen to it outside?
It is very noticeable inside the cabin, especially while driving, and particularly when the car is running in electric mode. It’s also quite unpleasant to hear from outside. In the video it doesn’t seem as obvious because the engine noise partially masks it.
I couldn't find any proper description about these valves but feels like there must be an input error (some sensor) which makes the relevant control unit change its opinion about the valve state while the state change actually should be very infrequent. So not a valve fault even if the noise comes from the valves.
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. I didn't know they had reintroduced those solenoid valves. In any case, on a modern Mercedes heating should not be controlled by heating water temperature but air flow flaps instead (unlike W124 etc.). I cannot see why those valves would pulse frequently.
