Bubbles in coolant surge tank
Thread Starter
Instructor
Joined: Oct 2014
Posts: 195
Likes: 14
Bubbles in coolant surge tank
Is it normal to have some bubbles pop up in the coolant surge tank? Last week it was 95 degrees and I was getting what can best be described as a burning coolant smell when coming to a stop. The smell was coming from the drivers side of the car. So I checked the coolant level and it wasn’t low. A week goes by and I can not smell coolant but there are bubbles in the surge tank. Right under the marking for the full line you can see a bubble, bubble, bubble, almost like a fish tank.
On a side note I went through a touchlless carwash the day before the smell, when I took my c6 through that same wash I would occasionally get a weird clutch smell. The bubbles have me concerned though.
car is a 2017 stingray m7 1lt with 17k miles
On a side note I went through a touchlless carwash the day before the smell, when I took my c6 through that same wash I would occasionally get a weird clutch smell. The bubbles have me concerned though.
car is a 2017 stingray m7 1lt with 17k miles
Racer
Joined: Nov 2015
Posts: 260
Likes: 87
From: Brighton MI
#1 - I hope for your sake it's nothing serious, however, a couple of things to look at. Surge tank is directly part of the coolant system, & is pressurized. Possible bubbles could be slight head gasket leak (again hopefully not).
A. If you're ambitious a cylinder leak down test will show up small leaks.
B. Not scientific, however, you start a cold engine & let it run for a minute or two - Then slowly remove the coolant system pressure cap to see if there is any pressure in the system. Cold start should not cause any pressure. Many years ago had a company pool vehicle that exhibited this, along with a slight loss of coolant - Took to dealer who did a simple compression test which will not show up a slight leak. Told them to replace head gasket - Issue was resolved. As stated above, cylinder leak down is good analysis.
Good luck.
A. If you're ambitious a cylinder leak down test will show up small leaks.
B. Not scientific, however, you start a cold engine & let it run for a minute or two - Then slowly remove the coolant system pressure cap to see if there is any pressure in the system. Cold start should not cause any pressure. Many years ago had a company pool vehicle that exhibited this, along with a slight loss of coolant - Took to dealer who did a simple compression test which will not show up a slight leak. Told them to replace head gasket - Issue was resolved. As stated above, cylinder leak down is good analysis.
Good luck.
Thread Starter
Instructor
Joined: Oct 2014
Posts: 195
Likes: 14
Thank you for the advice, that is what I was preparing to do this afternoon. I just noticed that when I remove the cap to the coolant tank, there are not actually bubbles, but rather coolant dripping out of the hard line that crosses the top of the air box. Which is splashing into the tank and creating the appearance of bubbling when the cap is on. Might just be me over reacting.
Thanks
Thanks
