Date: Sat, 18 Jun 2016 11:45:11 -0700
Reply-To: Scott - IMAP <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott - IMAP <scottdaniel@TURBOVANS.COM>
Subject: Re: Coolant mystery
In-Reply-To: <BAY405-EAS402F60634CE1C09C8EBA227A0280@phx.gbl>
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The suggestion to retorque head bolts is a good one ( tho I havn't seen
any waterboxer heads get loose ever...just head and/or gasket issues ) .
As stated, there is risk sometimes..that the head nuts might not
unscrew, but rather a stud bread off down at the bottom of the stud in
the case. If that happens you are definitely screwed !
For sure, residual pressure is not normal or a good sign at all.
Leak down test MIGHT reveal which side the problem is on ..'might' .
or if wanting to keep it limited in scope for now ...if you can't
diagnose the problem to one side or the other, just do one head
carefully ..then see how it goes. Most of the time that I've seen if
there is a problem on one side, it's the right head rather than the
left, fwiw.
if you know the engine is very due for a head job anyway ..might start
thinking about that.
It's a 2.1 ( as opposed to 1.9 ) I imagine.
I'm sure you'll keep us informed about how it goes.
Scott
On 6/18/2016 6:55 AM, Dennis Haynes wrote:
> This is something that needs attention and diagnosis might turn out to be difficult. This may as simple as the system is low on coolant enough that the normal process of expansion and contraction can’t purge the air out and pull ne coolant in. The trick with these systems is that filling and bleeding/purging has to be done with the engine cold. So here are the first steps.
>
> Engine cold like n morning
> Open cap and have coolant bottle ready to pour.
> Start engine and get revved to 1,800-2,000 rpm.
> Coolant will suck down.
> Top off coolant and fill to top.
> Re-install pressure cap.
> Let engine come down to idle.
> Install cap to overflow tank hose and fill that tank as needed.
> You should be good.
>
> Now if coolant gets pushed out you either have a bad cap or you are getting combustion gases in the coolant.
> Cracks heads will be fairly consistent with making the problem come back. Leakage from where the cylinders meet the heads always start out from the heads coming loose. Most test methods will no pick this up until it is really bad. Loose heads will have symptoms change based on temperature and load. Yes engine load. Increased loads lift the heads off the cylinders. Torqueing is the fix. There is a risk as the studs loosing preload can also indicate a future failure and bad ones may break. Broken head studs make for a very bad day.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Eric Caron
> Sent: Friday, June 17, 2016 4:31 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Coolant mystery
>
> OK folks,
>
> Be gentle here as coolant questions way to often end up with very scary responses.
>
> I’ve noticed that even a few days after a bus trip the van has air in the expansion tank. usually the tank is about 3 fourths full. If I turn the blue cap I hear bubbles and sound of pressure. today a sighted friend told me that when I did this the expansion tank filled up with coolant. Interestingly the level of the over flow tank never seams to change.
>
> The van was recently checked out at a VW shop and he was suspicious that a tiny seep of coolant might be coming from one head but it was so slight he could not be sure.
>
> So, my van seems to build up pressure when running and holds it for several days. Once released the expansion tank fills but level of overflow seems consistent.
>
> Is this normal or a sign of something needing attention.
>
> temp indicator is consistently just below the led.
>
> Eric Caron
> 85 GL Auto Westfalia
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