Goss408

iTrader: (2)

I have a running water sound from behind the dash that I have determined in my non professional opinion to be air in my cooling system. I filled the turbo coolant reservoir, the radiator overflow, and the radiator itself to capacity/full line (the turbo reservoir took a small amount and the overflow took a good amount to get to the full line), and ran the car between 2500-3000RPM for a 10 minute interval. I then let the car cool, and refilled everything to capacity (only the turbo reservoir took anything) but still had the running water sound. I ran it again for 5 minutes between 2500-3000RPM again, which is where I sit now waiting for the car to cool.

I have a couple questions from my experience thus far:

1. The engine dropped out of my controlled RPMs and "pulsed" between 1000-2000 RPM on its own with out any movement of my foot and continued to "pulse" like that until I let off the gas. It did it during both RPM intervals.
Can anyone tell me why this happened and what it means?

2. Am I going about this correctly? Or is there some secret "not in the owners manual" way to get the air out of there that would ease the process? Everything I get in searching the internet comes back with a bunch of variations of the previous persons suggestions.

I apologize in advance if this "belongs" in a particular forum area, but I didn't see anywhere that struck me as appropriate. Thanks for any helpful responses in advance as well.

Irish_car_B0mb

iTrader: (3)

burping involves running the car after filling with fluid and squeezing the lower radiator hose slightly to help get the air out as to not have the water pump get air gaps which pressurize and simulate overheating until the coolant gets back into. i think its clled vapor lock or something.

as far as the pulsing maybe its not firing all cylinders. i had something similar happen after my car died and i unmaried my accessport, all that fixed it was to turn the car off and turn it back on.

the water movement sound may be that there is air in the system and if the line/hoses arent full of coolant you might be hearing the liquid moving around passed the air.

just my $.02 without hearing it or seeing it its all just shot in the dark for me.

de_engineered

iTrader: (24)

I have a burping funnel if you wana borrow it. Really the ideal way to get *all* the air out.

91vtec

iTrader: (11)

I had this happen to me and found that the drain holes from the engine bay was clogged causing water to stay there and swerve side to side until evaporated or drained

I should say i experienced this and not actually happen to my suby

Civic and dodge caravan and i think my golf too


Just something you can check.

Will need to take off the plastic trim between engine bay and windshield if that makes any sense

Goss408

iTrader: (2)

The pulsing seemed more like some sort of safety feature triggered by constant higher than idle RPMs while in nuetral. It didn't trigger any CEL's or anything.

Much appreciated, if what I did does not work, I may take you up on your offer.

I did read a few different posts about this being an alternate problem. I will check it out if the burping doesn't work.


Thanks for the replies folks!

Concillian

iTrader: (2)

Typically the issue with the turbo Subarus is getting it up through the highest part of the tank and down the side by the turbo.

You can either take that hose off the tank and pour some coolant down that side or you do the put a burping funnel on the tank and let it idle until it comes up to temp. This raises the coolant level until it is over the top of that hose that comes out of the top tank, and coolant flows down the turbo side. There must be some gaps over there that don't fill completely through a normal fill.

Either way works, but I tend to fill the tank, then pull the hose off the turbo side and fill that through a small funnel. Then it usually doesn't need idling / burping.

queeg9k

iTrader: (11)

I have that same burping funnel. Took me approximately 45 min until it stopped bubbling and it drank over a quart more coolant in the process.

Oh and make sure your heater is on while you do it as that system can hide some air in it. Squeeze the upper radiator hose and any other coolant lines you can reach.

I would recommend picking up the Lisle/Spill free funnel or making your own. You can JB weld a funnel to an old radiator cap.

Heedz

iTrader: (51)

Also hold your rpms around 3k for a while too. Get those fans running.

Gancherov

iTrader: (13)

If you can hear it in the cabin it is because you have bubbles going through your heater core under the dash. You need to run the heater at full blast while you burp the system like others have said.

I had a 1000-2000rpm pulsing as well, it went away after I cleaned the Idle Aid Control Valve and MAF sensor.

wombatsauce

iTrader: (7)

People have mentioned good and necessary things here. I would just add that for my own times through this process, I leave the heater OFF until the fans have kicked on the first time. Once the fans kick on, I turn on the heater - often times you can hear a surge of the bubble noises you heard before as you do this. I also rev it between 2k-3krpm but let it idle for a good while as well. Reving it up and holding it can knock bubbles out of areas.

I have had good results bringing the front end a little higher as well, though I am not 100% sure this is necessary. My driveway slants downward and I always ended up doing this with the car parked in the driveway facing the garage. Usually I would do it like this:

IMHO car should be fully cooled, as in sat over-night. Park car, or put it up on ramps on the front wheels, open radiator cap, insert funnel thingy and often a drain hose depending on the situation, start the engine with the heater OFF. Check on it periodically - or sit there and watch it. You can SEE when the t-stat opens because the coolant level will drop a bit for a short time, and then usually you will see a bit of bubbles at this time. The top of the radiator should begin to feel warm. You can turn on the heater at this point if you are SURE the T-stat has opened. You can keep tabs on the heating progress by feeling the radiator hoses. If I get a good amount of bubbles at that point, and the fans have kicked on at least once, I might put the cap on, make sure the reservoir is OVER-filled, and let it cool until tomorrow. Do it again the next morning. If things look good, take it for a drive and pay close attention. Check the reservoir.

This is why I start with the heater off, even on cars like the Justy that always keep the heater core in cycle: Especially on early Imprezas and my Justy, having the heater on is enough to never have the fans kick on, never let the T-stat open, which means it does not get up to temperature - this is why I engage the heater after the fans have turned on the first time, or verifying that the T-stat has opened. WRX may be different - can't remember, but having my heater blowing full blast was enough to keep my WRX from over-heating the last time I had a cooling system issue (enough to limp home).