Air Bubbles In The Coolant?

[Guest mrinverted232]

Hi

 

is it normal to have air bubbles in the coolant , ( see attached ) when the car is idling the air bubbles are very apparent.

 

I have been told that a head gasket fault , blowing air into the coolant could have this affect , should I have concerns or is a few bubbles normal.

 

I dropped the oil yesterday, no evidence of water in the oil, it was spotless, the dipstick appears clean, and the oil filler cap is clean as a whistle.

 

My 3 rd post in the last 2 weeks, cant thank you guys enough for the great tips and advice so far....

 

Thanks

Craig

[Guest mcramsay]

Does the level rise and bubbles get worse if you apply some throttle? Have you recently changed the coolant ? Possibly may be air bleeding from the system

 

If it gets worse when you'll hold the engine above idle RPM it is most likely to be the head gasket

[Guest mrinverted232]

Hi

 

Yes changed the coolant yesterday 50 50 mix of water and summer coolant.

 

If I hold the engine revs above idle the water level drops and passes by so fast its hard to see any bubbles.

 

Thanks

[Guest mcramsay]

It sounds like it may just be air escaping from the system after filling up.

 

From cold run the engine with the rap cap off, allow the car to warm up and the fan cut in, the water level in the red should drop when the Thermostat opens, top up the level when it drops, you can also squeeze the top and bottom rad hoses to help trapped air escape.

 

If it is trapped air the bubbles should stop after a bit of idling.

[Guest mrinverted232]

Hi mcramsay

 

Thanks for the response, have a feeling the head gasket has gone, tried everything suggested, flushed and refilled, bled the system several times form the highest point, and still bubbles .

[maccavvy]

have a sniff test done this will confirm combustion gases or air bubbles

[Guest mrinverted232]

Hi good advice , I have organised a sniff tester, never used one before but..........I apparently stick it in the expansion bottle and watch for a color change , quote the mechanic.

 

Thanks for the response,

Craig

[Longboarder]

The idea is to allow whatever gas is making up the bubbles to bubble through the blue test liquid. You should not mix it with the coolant or let it be contaminated by the coolant. Ideal is to draw off some coolant from the top of the rad so no coolant blows/expands into the test vessel. Connect a tube from the rad cap neck and lead it into the vessel containing the test liquid. With a plain cap on the rad if you have one or the usual cap but the lower seal lifted to allow easy escape of the bubbles run the engine and let the escaping gas bubble through the test liquid for a few minutes. The liquid goes paler and then orangey/yellowy/pale brown if it detects exhaust gas in the bubbles. This confirms head gasket blown. If it stays blue then gasket not blown.

 

Nigel

 

There is a special 'test-tube' with a rubber bung that you simple add the liquid to and insert in the radcap neck, once again having removed some coolant.

[Guest mrinverted232]

Hi Thanks Nigel,

 

Used the tester, done exactly as you said, this unit required you to fill 2 glass tubes put them together with a bulb on one end and a bung on the other, place in the top of the radiator ensuring 1.5" of clearance . Do not draw any coolant into the liquid, squeeze the bulb 3 times and release slowly allowing the air to filter through the liquids, if the liquid turns yellow head gasket gone.

 

Done this twice and the good news is the liquid stayed blue, so head gasket OK.

 

Thanks

[Longboarder]

I would do more than three times on the basis you don't want to miss a small leak by taking too small a sample. Test is sensitive and a negative is very reassuring. So it's probably airlocks in the system and the system is not self purging air as it heats up and then refilling with coolant on cooling down. Must be drawing air back in as it cools.

 

Nigel