Radiator Cap Issue (Gurgling Sound)

[Flxr_88]

I have recently bought a 2005 Legacy GT (wagon if it matters) and had a smell of what I thought was burning oil. I did an oil change and put valvoline high mileage 5w-30 in, filled all 4.4 quarts and replaced the oil filter with a full synthetic oil filter. All in precaution as it has over 150k miles on it. I still smelled what I thought was oil, drove the car for a while, and still smelled it. Kept putting carboard under the car and saw no leaks, but noticed it was sucking coolant. I drove it yesterday, saw it smoking from the scoop stopped and heard a almost gargling from the radiator tank cap. Like sucking on a straw. Went straight to autozone and picked up a new cap. Filled the coolant and the smell is gone, no smoke and engine felt cooler. Still though, I heard that sound coming from the overflow resivour. (I also filled it up with the subaru coolant and conditioner, and it had its head gaskets replaced some thousands of miles ago, no more than 20k.) Any help is awesome.+

[KZJonny]

Keep an eye on coolant levels over the next little while and don't let the coolant in the reservoir get below the overflow/pickup hose. Sounds to me like maybe the car was low on coolant to begin with, and the rad cap was making the problem worse.

If you didn't bleed/burp the system when topping off and replacing the cap, then perhaps there was some air trapped in it that is working it's way out now. I prefer to use a bleeder funnel when adding coolant, but others here like to jack up the passenger front of the car to encourage any trapped air to leave via the turbo coolant vessel. Someone might prove me wrong, but the "Subaru coolant conditioner" was a thing for the 2.5i's with the coated head gaskets that failed. Shouldn't be needed for your turbo engine with MLS head gaskets. Read: don't waste your money on it next time. The noise from the reservoir may well be the hot coolant that continues to circulate in the system as it cools the turbo down when you park it. M Sprank wrote an explanation of that system elsewhere on the site, it's why we don't need a turbo timer etc... on these cars, but it does mean you might hear coolant for a while after you shut it down.

 

[Flxr_88]

Awesome. Thank you! Just ordered a bleeder funnel from amazon. I may also add that there seems to be some smoke coming from around the Turbo. Coolant was sucked again had to add some more. And one more thing. There was a vacuum leak in which the intercooler had to be removed. I had this done by Six Star Motors in Illinois. Could they have forgot to bleed it? I would think it would be a rookie mistake though. Or may this be a coolant leak. And how would I go about troubleshooting, or finding the leak?

[GearJamr]

I had something similar a few years ago.  It was one of the coolant lines to the turbo had corroded and developed a hole.  Chances are that's the case here too.  I had it bad, with sweet coolant smoke pouring out from the scoop, underneath the car, anywhere it could come out.  I'd get that narrowed down before it gets that bad.

[KZJonny]

+1 to the above.

if you bleed the system to where there is no air, and the reservoir if full to where it can’t suck air, but you’re still ending up with air bubbles and gurgling…. You’ve got a leak somewhere. Or…. Failing head gaskets that are pushing combustion gas into the coolant passages. I know you said they were done recently, but it’s alwqys possible they weren’t done *well*.

A pressure test may help at that point, but also dried coolant usually leaves a pretty easy to find crust…