tapping noise from radiator?
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Joined: Feb 2017
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2012 ML350 BT
tapping noise from radiator?
Hi everyone, in the last few weeks, twice I noticed a tapping/knocking noise coming from radiator valve hose after shutting off the car. The noise lasts about 15 mins. It's hard to tell where it's from exactly. Here is a video. It's a 2012 ML350.
I kept eyes on the following since I noticed it the first time a few weeks ago.
- coolant level looks ok
- engine temp gauge has been normal
- haven't noticed any excessive white smoke from exhaust
- coolant reservoir cap looks ok. no residue around it.
- don't see any leaks on the ground.
- heard gurgling sound near the coolant reservoir once
- smelled slight sulfur like smell from exhaust a few times after shutting off car and getting out
Any suggestions? Thanks!
I kept eyes on the following since I noticed it the first time a few weeks ago.
- coolant level looks ok
- engine temp gauge has been normal
- haven't noticed any excessive white smoke from exhaust
- coolant reservoir cap looks ok. no residue around it.
- don't see any leaks on the ground.
- heard gurgling sound near the coolant reservoir once
- smelled slight sulfur like smell from exhaust a few times after shutting off car and getting out
Any suggestions? Thanks!
Last edited by dadiz; Feb 17, 2017 at 01:12 AM.
MBWorld Fanatic!
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
The noise may be coming from the purge valve. It's located right next to the coolant tank. Put your hand on that valve when that noise is present and see if that's the case...
