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E1
Samba Member
Joined: January 21, 2013
Posts: 8738
Location: Westfalia, Earth
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 Posted: Sat Aug 16, 2025 1:29 pm Post subject: Re: Blown head gasket or something else? |
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| my_vw_sucks wrote: |
| Crooked Designer wrote: |
Simple test on the blue cap. I have never done this as by the time I became aware of this video I already moved on to an aluminum expansion tank, but seems pretty simple.
Link
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Ran the test and have a dying trumpet and can easily drink a coke through the cap (no closed b-hole on this one). Back to being optimistic. That new cap needs to hurry up. |
No Coke, Pepsi. 
Awesome. The suck test shows the *much-more* important flaw, not holding 1 bar. Fingers crossed.
FWIW you should always carry another spare (we have like three ). I’ve only been getting Meyles which are fine, but Blaus seemed a little more reliable.
Regardless, hopes and odds high that this is all it was!
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?Waldo?
Samba Member
Joined: February 22, 2006
Posts: 10131
Location: Where?
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| Posted: Sat Aug 16, 2025 2:24 pm Post subject: Re: Blown head gasket or something else? |
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| my_vw_sucks wrote: |
| My first thought was maybe blown head-gasket pressurizing the cooling system. But coolant is very, very clean. Checked the oil and that too is clean. No signs of milkshake. |
This sort of comment regarding head gaskets is very common but demonstrates a misunderstanding about the function of head gaskets in most engines along with a misunderstanding of how they fail.
The different symptoms of head gasket failure are not typically cumulative. In other words, you typically get only ONE symptom, e.g. ONLY exhaust gases in the coolant, OR ONLY oil in the coolant, OR ONLY coolant in the oil, OR ONLY coolant leaking to the exterior of the engine, OR ONLY oil leaking to the exterior of the engine. Sometimes severe overheating or some other dramatic event can combine more than one symptom, but those cases are rare.
In other words, if you have a symptom that indicates that exhaust gases are getting into the coolant, that could indicate a blown head gasket. The lack of milkshake in the sump or lack of oil in the coolant reservoir in that situation is completely irrelevant. The lack of other symptoms cannot be taken as any sort of indication that the head gasket is not blown.
The Vanagon 'head gaskets' are also quite unique and comprised of individual orings/gaskets between the individual cylinders, the head, the sump and large rubber gaskets between the block and the heads. Those again fail in individual ways and have individual symptoms. Failure of the orings at the base of the cylinders will allow coolant into the sump creating milkshake in the oil. Failure of the large rubber gaskets will allow coolant to leak to the exterior of the engine. Failure of the fire rings between the head and cylinders will allow combustion gases into the coolant. Those symptoms are individual to the particular failure mode and a lack of another symptom from a different failure mode does not in any way indicate that the 'head gaskets' have not failed in the manner that the single symptom indicates.
I'm not trying to say your head gasket has failed or has not failed. Just giving information that might help you perform your due diligence to determine that for yourself. |
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my_vw_sucks
Samba Member
Joined: June 08, 2016
Posts: 58
Location: Bay Area
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| Posted: Wed Nov 05, 2025 10:06 pm Post subject: Re: Blown head gasket or something else? |
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I've been crazy busy with work, but finally got around to replacing my expansion tank cap. After driving a bit the coolant that had been forced to the resivoir migrated back into the system totally emptying it. With the van warm and the front parked on ramps on a slight uphill grade, I carefully cracked the bleeder valve on the radiator. Only air escaped. I topped up the radiator using a thin hose and funnel into the bleeder vavle opening. Once full I closed it up, topped up the resivoir, and took a quick test drive. When I got back to my house I checked the resivoir level and it had stayed steady. I cracked the radiator bleeder valve again and coolant flowed out.
I've been driving it for the last week and everything looks all good. The only thing I've noticed is that the radiator fan comes on for a very short period on start up. I don't recall if it always did this or not.
Anyways thanks for the help! On to the next project; rebuilding the motor in my 74 2002tii. This time the head gasket actually is bad (and no there's isn't any oil in the coolant...).
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Franklinstower
Samba Member
Joined: September 21, 2006
Posts: 2010
Location: PNW
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| Posted: Wed Nov 05, 2025 11:00 pm Post subject: Re: Blown head gasket or something else? |
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'74tii with '72 bumpers? Or gray market?
Chamonix White?
Love it!
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'75 Miami Blue Sunroof FI Standard Bug
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my_vw_sucks
Samba Member
Joined: June 08, 2016
Posts: 58
Location: Bay Area
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| Posted: Mon Nov 10, 2025 9:09 pm Post subject: Re: Blown head gasket or something else? |
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| Franklinstower wrote: |
'74tii with '72 bumpers? Or gray market?
Chamonix White?
Love it! |
First thing I did was ditch the diving boards. Color is Sahara. |
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