Date: Sat, 26 Jan 2013 19:38:47 -0800
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Coolant Overpressurization / Head Gasket Leak
In-Reply-To: <BAY152-ds2D17FCA6E5925A0B7CA4AA0190@phx.gbl>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
worth a try.
Might mention that coolant will come out if head nuts are loosened (
drain coolant first )
and that each nut needs to be resealed ..
as they seal in coolant.
S.,
On 1/26/2013 7:02 PM, Dennis Haynes wrote:
> You definitely need to do some testing to try to determine why the
> compression is down on those two cylinders. Before pulling the heads I would
> check the torque on the head nuts. Internal leaks between the tops of the
> cylinders and heads are really due to failure of the studs to keep the heads
> down under those compressive/pressure loads and the temperature changes of
> the engine parts. I have repaired a number of internal leak issues by
> re-torqueing the heads. The other failure point is cracked heads allowing
> the gasses into the cooling system. Coolant-hydrocarbon testing is not
> always effective for diagnosing. As part of the leak down test, by pass the
> gauge and apply full shop air pressure to the cylinders (secure the
> crankshaft securely) may make the leak obvious.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Walter Houle
> Sent: Saturday, January 26, 2013 8:08 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Coolant Overpressurization / Head Gasket Leak
>
> The morning after the 300 mile drive home from BBB I noticed that the
> coolant overfolw tank was full and overflowing a few drips. The expansion
> tank was also 100% full. I opened the pressure cap a little bit at a time
> and a lot of coolant pushed out - this on a stone cold engine that was
> sitting for 12 hours. It looks like I have an internal head gasket leak.
> The strange part was that the van ran strong all the way home and didn't
> show any obvious signs of overheating. We stopped and checked it twice along
> the way, no drips, no smell, and no excess heat. The temp gauge was over the
> right edge of LED and it behaved normally, up a tad on the climbs, and down
> a tad on the descents, just like always. I did a compression test today and
> it was 170-170-140-150. Its been low on 3 & 4 like that for a while, last
> test was 6 months ago, but this is the first time I've had coolant issues.
> I will try a hydrocarbon sniff of the coolant and then a leakdown test to
> confirm. I've read a lot in the archives, and its looking more and more like
> its a compression leak, and it looks like it is only occuring under load.
> The heads are old and have never been off, original VW factory rebuild, 15
> years and 75K miles ago.
> Yes, this is way overdue and I should have taken care of this earlier.
>
> I am assumming new heads are in order, and I'm hoping that is going to be
> it. What about the rest of the engine? If it was pushing coolant away from
> the cylinders, it was doing it for a long period of time. WHat else should I
> be looking at?
>
> Thanks,
> Walter
> 1985 Vanagon 1.9 in San Diego
>
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