Date: Sat, 29 Jul 2017 13:15:57 -0700
Reply-To: Neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Neil N <musomuso@GMAIL.COM>
Subject: Re: Engine worries return
In-Reply-To: <CY1PR20MB0029CDAFEBA70D67E0B12BFEA0BC0@CY1PR20MB0029.namprd20.prod.outlook.com>
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> ...... then future failures are really a symptom that the cap is being exposed to
> hot combustion gasses or steam.
Ahhhh, ok. I see. To quote the "Big Lebowski" 'My thinking on this
has been all wrong, man'.
> You will get additional expansion as the system
> saturates with heat and temperatures go above normal which will occur during
> high ambient temps and long extended loads. There are a lot of dynamics
> occurring here. The trick is for the system to allow for all the expansion
> needed and that coolant to remain in the recovery tank and then during cool
> down that fluid to be returned to the system. If coolant get pushed out
> enough to make a mess or need replacement you have a problem.
Ok. I see. It sounds like Eric and I have a similar issue. Hope this
helps Eric too.
Eric: for what it's worth, I regret not checking coolant pressure
before checking head nut torque. I didn't feel any nuts that were
obviously loose but did tighten a few by about 1/4 turn using a beam
torque wrench. After that, I ran the engine for at least 20 minutes. (
rad fan cycled on off quite a few times ) Cooling system pressure was
fine. And, the issue has not cropped up on short trips. All that said,
it sounds like your 1.9 and my 2.1 are suffering from an over
pressurized cooling system that happens only under certain driving
conditions.
Neil.
On 7/28/17, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> At the point that coolant is sometimes blowing out blaming the cap is often
> wishful thinking. If the cooling system is tight (leak free) and you are not
> getting gasses into the cooling system it will work even with a defective
> cap. As bad as the quality of some caps are, if they work when installed
> then future failures are really a symptom that the cap is being exposed to
> hot combustion gasses or steam. With the recovery tank set up after the cap
> once the system is truly air free the cap will have to release pressure at
> every warm up cycle. Coolant expansion occurs as various parts of the
> coolant system increase temperature. You have expansion in the engine as it
> warms and then you have the varying expansion due to radiator, heater core,
> and pipe-hose temperatures. You will get additional expansion as the system
> saturates with heat and temperatures go above normal which will occur during
> high ambient temps and long extended loads. There are a lot of dynamics
> occurring here. The trick is for the system to allow for all the expansion
> needed and that coolant to remain in the recovery tank and then during cool
> down that fluid to be returned to the system. If coolant get pushed out
> enough to make a mess or need replacement you have a problem.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Neil N
> Sent: Friday, July 28, 2017 12:03 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Engine worries return
>
> This is likely moot, as it sounds like the cap(s) failed,
> My '88 also gushed coolant after a long hard drive then a bunch of stop and
> go traffic on a hot day so this may be wishful thinking on my part,
--
Neil n
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