Date: Sun, 25 Apr 2010 23:52:19 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: cooling system diagnostic help? Long,
lots of info about whats been done so far.
In-Reply-To: <y2n6bc66ccf1004252014ifa2cd647xceffd873abf43fb4@mail.gmail.com>
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It is more common for head gasket failures or cracked heads to show up as
combustion products getting into the coolant than coolant getting into the
combustion chambers. Gasses travel through smaller breaches than liquid
especially with the help of heat and pressure.
Anytime a cooling system fails, (boil over or coolant/pressure loss), there
is a chance of damage. The in line 4 engines are prone to head cracking from
this. If a head gasket fails, simple replacement is often a temporary fix.
The head and or block may need machining for a proper fix.
There are a number of ways the head or gaskets can be tested.
A combustion leak detector kit can be had for about $50. Napa part #
700-1006.
Performing a leak down test, no gauge set, shop air directly into the
cylinder while the pressure cap is open will show bubbling or rising level
if the failure is large enough. This has the advantage of showing which
cylinder is the problem.
When done fix that coolant level light. Warning lights are there to warn
when things go wrong. Checking the fluids is nice (and important) but do not
help when things like hoses or belts fail.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Don Hanson
Sent: Sunday, April 25, 2010 11:14 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: cooling system diagnostic help? Long, lots of info about whats
been done so far.
If it is a head problem it is not showing in the cylinders.
I didn't include that when I did this preliminary diagnostic this evening I
did not totally re fill and re-bleed the cooling system. The pressure tank
was empty after my boil-over incident. I simply poured in enough water to
fill it and then started up the motor...so the bubbles coming into the
pressure tank may (fingers crossed) have been some air coming from the hoses
and empty cooling passages....But the over-full episode kinda makes maybe
wishfull thinking.
Might be time to go get that $300 used motor I've been looking at....It IS
a vw...every vw should have a spare motor, right?
This van came to me with a full-time blinking coolant light and I couldn't
get it to stop...The previous owner said he also had tried but gave up and
just let that sucker blink all the time. I put some tape over it and having
been driving without a problem for over two years and about 40k
miles...watching the temp gauge and checking the coolant level every oil
check...which means every fill up of gas...I always check my oil...left over
from my air cooled days, I guess.
Is there a way to check the integrity of a head/head gasket when the leak
is not letting coolant into the cylinders? Or do I pull the head? Takes
about 4 hrs, but could there be a flaw/fault that I wouldn't see by eye?
Ugg, was not planning on this deal..
Don Hanson
On Sun, Apr 25, 2010 at 7:36 PM, mark drillock <mdrillock@cox.net> wrote:
> Sounds like a blown head gasket or cracked head, either letting combustion
> gases into the cooling system. The combustion gases are 1000s of psi so it
> takes only a tiny and brief breech for a small gas bubble to get through
and
> then expand in the much lower pressure cooling system. The fact that
coolant
> doesn't yet leak the other way doesn't matter to this possible diagnosis
as
> that takes a larger problem.
>
> When you say your temp led doesn't work do you mean it doesn't blink a few
> times every time you turn on the key?
>
> Mark
>
>
> Don Hanson wrote:
>
>> Hi all, recently I've noticed my cooling system is being weird.
>> Don Hanson
>>
>>