# Help needed coolant issues

**URL:** <https://community.cartalk.com/t/help-needed-coolant-issues/91202>\
**Category:** Maintenance/Repairs\
**Created:** [September 17, 2015, 5:26pm UTC](https://community.cartalk.com/t/help-needed-coolant-issues/91202 "2015-09-17T17:26:58Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Sschreiber27](https://avatars.discourse-cdn.com/v4/letter/s/2bfe46/32.png) [@Sschreiber27](https://community.cartalk.com/u/Sschreiber27)\
**Post date:** [September 17, 2015, 5:26pm UTC](https://community.cartalk.com/t/help-needed-coolant-issues/91202/1 "2015-09-17T17:26:58Z")

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I have a 98 mitsubishi triton v6 3.0, I am confused with a issue I am having, coolant heats up and is put into reservoir tank as normal, but when car cools down it does not suck it back into radiator.

Have purchased new radiator cap  
No coolant on ground or any visible leaks in engine bay  
No white smoke when starting car or running  
No sweet smell of coolant burning  
No leaks inside heater  
Car doesn’t overheat, just pushes more coolant Into reservoir  
Slight bubbles in radiator when cap off  
No coolant in oil  
Put a bottle of radiator leak fix in, no improvement,

Only thing is that 3 out of 5 intake manifold bolts are stuffed, they grab but don’t get a tight fit, could this cause the vacuum leak not returning the coolant to radiator

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**Author:** ![melott](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/melott/32/10827_2.png) [@melott](https://community.cartalk.com/u/melott)\
**Post date:** [September 17, 2015, 5:38pm UTC](https://community.cartalk.com/t/help-needed-coolant-issues/91202/2 "2015-09-17T17:38:01Z")

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After you let it fully cool off, and take the cap off (presuming you can see into the radiator), is the fluid level in there down? If it is, but hasn’t sucked fluid back in, maybe there is some kind of a leak in the overflow hose…???

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**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\
**Post date:** [September 18, 2015, 3:34am UTC](https://community.cartalk.com/t/help-needed-coolant-issues/91202/3 "2015-09-18T03:34:44Z")

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Possible head gasket failure comes to mind.

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**Author:** ![Sschreiber27](https://avatars.discourse-cdn.com/v4/letter/s/2bfe46/32.png) [@Sschreiber27](https://community.cartalk.com/u/Sschreiber27)\
**Post date:** [September 18, 2015, 4:34am UTC](https://community.cartalk.com/t/help-needed-coolant-issues/91202/4 "2015-09-18T04:34:49Z")

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Just been to the radiator specialist, he’s booked me in for more test as the block test didn’t show a head gasket issue

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**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\
**Post date:** [September 18, 2015, 6:16am UTC](https://community.cartalk.com/t/help-needed-coolant-issues/91202/5 "2015-09-18T06:16:22Z")

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So the hot coolant moves into the bottle when the engine is hot, but it doesn’t go back into the radiator as the engine cools? Just curious, what caused you to discover this?

Bubbles in the coolant when looking into the radiator could mean a head gasket leak. That would be exhaust gas getting into the coolant causing the bubbles. Since exhaust gas is mostly CO2, and CO2 combines with water to form carbonic acid, it seems like if you measured the pH of the coolant, that might provide a clue. If it is abnormally acidic, that could mean exhaust gas in the coolant as a result of a head gasket leak.

But it’s possible for small bubbles to appear in the coolant in the radiator if there’s some trapped or dissolved air in the coolant, like if you’ve recently added new coolant say. But then the coolant wouldn’t measure acidic either. So that’s the way to tell.

@melott 's comment about a possible leak in the overflow hose is a good one. Have you ever tried to suck a soda straw for a sip of coca-cola only to discover you can’t b/c there’s leak in the straw? Same thing, that hose has to be leak free for it to be able to draw the coolant back into the radiator. So ask your shop to test for that, and that all the connections are open. They could use one of those hand-held vacuum pump to easily test for that. On some cooling systems the overflow tank is designed to be pressurized too. So if your overflow tank developed an air leak, maybe this could result, not sure, but worth asking your shop about. Best of luck.

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**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\
**Post date:** [September 18, 2015, 6:47am UTC](https://community.cartalk.com/t/help-needed-coolant-issues/91202/6 "2015-09-18T06:47:24Z")

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“as the block test didn’t show a head gasket issue”

You naysayers need to step off now

There have been some among you that said the term block test was not correct

OP just used the term, and he doesn’t even know me

That should prove it’s common and correct usage

👅
