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Hello world! :)
Its been a long time since i have bubles in my coolant system... no progress... toyota said - "wait, and they will dissapear"... im waiting about 4 months... no progress in that "dissapearing" thing ;)
So maybe some of you know what to do...?
The fact is - when engine is cold (usually in morning) there is clearly hearable bubles running on when rpms rises above 1000... when system warms up (and coolant presure rises) the bubles is gone... until next cold startup...
Can anyone suggest something?

p.s. last month i changed radiator cap for brand new because old one was too bad - almost no rubber :)... no effect on bubles...
[RAV4, 1999, Automatic]
 
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megahiper,
Wow, are you really from Latvia?! I was in Riga in 1991...beautiful city and some of the friendliest people I've ever met...

But, I'd be a little concerned about having a head gasket leak if those bubbles don't disappear. I'd suggest getting something called a block tester, which will test for exhaust gasses in the coolant. The one I have has a blue fluid that will turn yellow if exhaust gas is found...it sits on top of the radiator and you leave it there while the engine heats up.

Do you have any other symptoms of a headgasket leak?

Bogatyr
 

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Question... was the new cap you put on a factory Toyota, or generic ? also was the bubbling there before? and has the coolant been changed recently ?

I know that usually when a flush and refill is done, usually the car is started with the cap off and then you give time for it to reach normal operating temperature ( usually you can wait until the radiator fan kicks on) then put the cap back on...

Generally this is done to get the air bubbles or air pockets out of the system... and if you are to try this I would recommend doing it when the car is cold, if it sat all night, do it in the morning...

Good luck...
 
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Bogatyr said:
Wow, are you really from Latvia?! I was in Riga in 1991...beautiful city and some of the friendliest people I've ever met...
Yeah... realy! :) hehe... everything is changed since 1991... but Riga is still a nice city :)... and i noticed your nick... seems from Russia natively?

Bogatyr said:
But, I'd be a little concerned about having a head gasket leak if those bubbles don't disappear. I'd suggest getting something called a block tester, which will test for exhaust gasses in the coolant. The one I have has a blue fluid that will turn yellow if exhaust gas is found...it sits on top of the radiator and you leave it there while the engine heats up.

Do you have any other symptoms of a headgasket leak?
I realy hope it is not because of the crack thingie... huh... that must be expensive... and what to you mean - other symptoms? Dont know about other symptoms...??? :/

And if its because of some crack - shouldnt it go for more bubbles? I mean there is no change since i bought this car, then changed coolant, then changed radiator cap... and now... not more not less bubbles... dammit

DJ Sueno said:
Question... was the new cap you put on a factory Toyota, or generic ? also was the bubbling there before? and has the coolant been changed recently ?

I know that usually when a flush and refill is done, usually the car is started with the cap off and then you give time for it to reach normal operating temperature ( usually you can wait until the radiator fan kicks on) then put the cap back on...

Generally this is done to get the air bubbles or air pockets out of the system... and if you are to try this I would recommend doing it when the car is cold, if it sat all night, do it in the morning...
First - ordered cap from toyota... was expensive, but original... same as previous! And yes - bubbles was there before and after cap change...
Yes - ive changed coolant... but there were bubbles in old coolant too... no change...
Tomorrow morning i should try this cap off starting thing... hmm... how comes toyota specs didnt suggest me that? ;)
 
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Discussion Starter #6
Probably it wasn't suggested because it's something a lot of mechanics/car owners already know, so they think that it's common knowledge. Really, though, if you didn't do the radiator flush yourself, whoever did it probably should have known to leave the cap off.

Unfortunately, the things that some mechanics and auto dealers take to be "common knowledge" can make a world of difference to someone relatively new to car maintenence. If you did the radiator flush yourself, the bubbles might well be from just recapping the radiator without having the engine heat up and run a bit first.

Oh, and by the way, the reason I was told for this practice is that, when you fill the radiator after it's been significantly emptied, air pockets form under parts of the radiator, like they would if you were to turn a drinking glass upside down in a sink and run water over it, only not as deep. Running the engine without the cap on the radiator helps to shake out these bubbles and settle the coolant in the radiator, so that more coolant can gradually be added to fill it up completely, to eliminate all air pockets in the radiator. You remove the air pockets in the radiator because the air expands at a different rate than the water and coolant (and the air space fills with steam from the heated water), and the different rates of expansion put a lot of stress on the radiator and can cause it to crack.

I'm not sure that this explanation is accurate, mind you, but it seems reasonable to me.
 

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megahiper said:
Can anyone suggest something?
Park on a steep hill (facing UP :wink: ) with the engine running and radiator cap off. Run it long enough to allow the thermostat to open up. This should burp the air out. If no steep hill handy... maybe you have a set of ramps you can pull up on 8). After it burps... you may need to top it off :? Replace the cap BEFORE turning the engine off.
 
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Turn heater on HOT and full blast while running engine. Might want to take her for a spin if you can. Should clear out most of the bubbles. You can run the engine with the cap off, but since the Rav has a plastic reservoir tank, not always necessary. If you have a headgasket leak, most telltale sign would be too look at your engine oil and/or filler cap. If there is a murky grayish muck, then that's your coolant leaking into the head and mixing with the oil. You might also want to get a used oil analysis if it continues to worry you for a definitive answer.
 
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Kelly Smith said:
Park on a steep hill (facing UP :wink: ) with the engine running and radiator cap off. Run it long enough to allow the thermostat to open up. This should burp the air out. If no steep hill handy... maybe you have a set of ramps you can pull up on 8). After it burps... you may need to top it off :? Replace the cap BEFORE turning the engine off.
Thanks Kelly-Site Admin!!! I really should try this... still cant understand why any service guy didnt mention anything like this... it is just so simple... dammit... maybe even this evening... huh... then report...
 
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Megahiper,
Yeah, if the cooling system wasn't bled out, you'll have air bubbles in there, but they should work themselves out after a few cycles. I'd still lean towards the head gasket.

Other symptoms are usually running warmer than usual, oil evidence in the coolant or coolant evidence in the oil. Although, sometimes, the leak is so slight, and only occurs under pressure that a gas test is the only way to find it...

Bogatyr
 
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