Fleemer

Recently replaced my radiator. Had a slight coolant leak on the lower rad hose due to improper clamp placement, system was getting air in it and consequently lots of air bubbles coming into overflow (not violently or anything just some bubbles)

Anyway, I've tried to burp it tonight to no avail. Lots of air seems to have gotten out, but I assume since i did it when the motor was warm that there is some air still trapped inside. (thsu the slow burp of bubbles, no constant stream)

Car doesn't smoke on start up and runs fine.

Problems only arrived after I put in my rad (old one was fine, no problems. Just upgraded to a dual pass rad)

Never had so much air problems with my s4, s5 is being a huge PITA.

Anyone know if air in the system would make it constantly bubble ever so slightly? Coolant system doesn't overheat or anything and infact the levels in the overflow expand/get sucked in accordingly : /

I have tried 3 diff rad caps. I checked all the hoses and no coolant leaks.

Lets hope for no coolant seals cause I didn't want o rebuild my motor this summer... (next summer was the plan lol)

jjcobm

iTrader: (18)

Bubbles coming out of the radiator cap area indicate an internal engine seal issue. Assuming you don't have one (pressure test if you can), you most likely have a hose that is allowing air to come into the cooling system causing the bubbles to get in and this will drive you nuts. Again, a pressure tester will serve a double purpose in this situation.

Check all hose clamps and make sure they are all snug. A properly working cooling system should take no longer than 10-15min to bleed.

Bleed by removing rad cap and running car with heater to full blast for 10-15min, topping off fluid as needed. For best results you can elevate the front of the car so that the highest point is the radiator cap area (where you are bleeding from). If you removed all coolant from engine, I like to remove the T-stat and fill up that cavity with coolant, then replace the T-stat and install radiator hose. That way the coolant will get hot and open up the t-stat when it needs to instead of having a giant air cavity.

Don't forget the small hose that leads to the overflow, I have heard this one causes problems if it is pinched where it goes through the front support area.

Hope this helps.

StevenL5975

Hello,

good information so far, but unfortunatly I got the same issue on my S4 NA after installation of a new radiator.
It drove fine for a week, we bleed the system properly and I installed an HKS pressure rad cap 1.1 Bar on the radiator (old rad had none so I got this one).

After a spirited drive there was white steam comming out under the hood at a stop, not much but noticeble. Temp was in normal range. Popped the hood and found lots of coolant
"spray" on the intake tube/hood and everywhere around. Coolant reservoir was also still at the "Full" level as before. Coolant spray came out of the upper rad cap (waterpump neck)

Once the engine was cold the upper coolant hose shrinked. Still with reservoir to "Full".
Since then I always top of and bleed the coolant before I start it and go to work.
Procedure is all morning the same, shrinked tube, open, top of, bleed, and drive.

Checked so far:

• Visco is working
• Undertray/fanshroud on place
• Coolant hoses and radiator get warm/hot
• No puddels under the car after parking
• Temp stays in the normal zone, no overheating
• Tubing to reservoir not bent
• Upper radiator hose only shrinkes when engines cools off

I am hoping for advice to fix this problem.
Help is greatly appreciated.

Thanks
Steven