Water noise from firewall

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jetstream87
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Water noise from firewall

Postby jetstream87 » Tue Dec 05, 2017 11:11 am

Lately I been noticing that my car is making this water noise when I start it up in the mornings (cold mornings), from what it seems to me it is coming from the firewall behind the dashboard. I have checked for leaks and negative results as well coolant level and negative on that as well. Can it be that I am having issue with my A/C as it only turns one at times except when the engine is hot? From what I research that it can be a leaking condenser or hose.


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smj999smj
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Postby smj999smj » Wed Dec 06, 2017 2:59 pm

Usually that's just the sound of the coolant running through the heater core that people hear and it's not a problem. You could try purging the system to make sure there isn't any air in the system to see if it helps. With the engine cold, remove the cap and install a "spill-free funnel."

https://images-na.ssl-images-amazon.com ... SX300_.jpg

Pinch off the return line to the reservoir and fill the funnel until the coolant reaches about 1/3 of the way up. Jack up the front of the vehicle as much as safely possible (or park uphill) and start the engine. Turn the heater(s) on to maximum heat and fix the throttle so the engine will run around 2000-3000 RPM. If you have a VG engine, crack open the air bleeder and purge any air out of it than close it. After about 10-15 minutes, make sure there are no air bubbles coming up through the coolant into the funnel and you have good heat coming out of the vents. If good, shut off the engine, remove the funnel and install the radiator cap. Lower the vehicle.

jetstream87
Posts: 172
Joined: Fri Nov 20, 2015 6:59 am

Postby jetstream87 » Thu Dec 07, 2017 12:19 pm

smj999smj wrote:Usually that's just the sound of the coolant running through the heater core that people hear and it's not a problem. You could try purging the system to make sure there isn't any air in the system to see if it helps. With the engine cold, remove the cap and install a "spill-free funnel."

https://images-na.ssl-images-amazon.com ... SX300_.jpg

Pinch off the return line to the reservoir and fill the funnel until the coolant reaches about 1/3 of the way up. Jack up the front of the vehicle as much as safely possible (or park uphill) and start the engine. Turn the heater(s) on to maximum heat and fix the throttle so the engine will run around 2000-3000 RPM. If you have a VG engine, crack open the air bleeder and purge any air out of it than close it. After about 10-15 minutes, make sure there are no air bubbles coming up through the coolant into the funnel and you have good heat coming out of the vents. If good, shut off the engine, remove the funnel and install the radiator cap. Lower the vehicle.

Thanks for the input going to try that, I have noticed that my A/C will not turn on once I run the car at a certain distance and with normal operating temperature. I am unsure if that is also a problem causing that issue, I will try that this weekend as this only happens during cold weather start up (47-55 F)

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smj999smj
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Location: Prospect, VA

Postby smj999smj » Fri Dec 08, 2017 12:43 am

I would think that the A/C is a separate problem. I would have an A/C performance test done with a set of gauges installed (it's detailed in the factory service manual). Thermistors (also called "thermal amps") can sometimes be faulty, too, causing the power to be cut to the compressor clutch. It sticks into the evaporator core and is meant to turn off the compressor if the evaporator core gets too cold (freezes).


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