Coolant hoses collapsed when cold
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Coolant hoses collapsed when cold
While doing my cam phasers, I noticed the coolant hoses were collapsed when the engine was cold. Does the M156 have a check valve in the cap that lets the coolant system suck air in when the engine cools down? My Volvo and Subaru both have that but I'm not sure if the M156 does. This probably means the cap on the coolant reservoir has failed, right?
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Joined: Oct 2023
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Ordered a new cap from FCP. For fun I took apart the old cap and found it was completely clogged with....sludge? New cap on the way, was surprised at how complex the cap is. In the last picture, you can see the small hole used for vacuum relief when the engine cools down. The spring that controls the check valve and the vent hole were completely clogged with crust and sludge.
Last edited by 0fc5dccf; Aug 7, 2024 at 02:26 PM.
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From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Nice and interesting piece of dissection. Guess its also time for a coolant flush and fresh coolant
