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1989 560 SL
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68 Posts
Discussion Starter #1
It's started to get colder here and I've noticed a bizarre sound from my dash on cold starts. It literally sounds like bubbling/water flow - as if a water pipe was running the length of the dash. It occurs when the ignition key is in the far right poisition just before you trun it to turn the engine. I can't repoduce it on warm starts. No water is leaking into the cabin. Is this sound normal?
 

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Premium Member
2010 Mercury Milan Hybrid, 1993 BMW 325i convertible
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6,077 Posts
It's started to get colder here and I've noticed a bizarre sound from my dash on cold starts. It literally sounds like bubbling/water flow - as if a water pipe was running the length of the dash. It occurs when the ignition key is in the far right poisition just before you trun it to turn the engine. I can't repoduce it on warm starts. No water is leaking into the cabin. Is this sound normal?
Aux heat pump (the little pump that helps send coolant through your heater core) and air in the cooling system? Only thing I can think of. IIRC, that pump only activates below a set temperature.
 

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Audi A8, Land Rover
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276 Posts
yep its air in the system.
 

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1989 560 SL
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68 Posts
Discussion Starter #4
I found this in another thread from Radiotek...
"Good. These things sometimes need to be "burped" after significant cooling system work. An indy told me to park with the front uphill or on ramps, fill it with the appropriate fluids, start the car with the pressure cap off, and top off until you can feel the small hose to the reservoir getting hot, and replace the cap. Then keep an eye on the temperature guage and coolant levels.

Scott"

Is there another way to purge the system? I've topped the collant off twice since August - maybe 2 cups each time.
 

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2000 SL500
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193 Posts
It should be ok with just replacing your pressure cap. The pressure valve in the cap is probably bad.

I just answered a similar question on my mid-term yesterday, lol.
 
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