[urq] Cooling System question

Mon Oct 15 04:29:44 PDT 2012

Another way of checking (quickly and easily) for a HG leak: When engine is
cold, start motor w/ reservoir cap on and then shut off w/o letting system
warm up (1 min or so).  Remove cap and see if there's a pressure release.
Also, another way is to start the cold motor w/ the cap removed and put
your palm over the open reservoir to create a seal.  Then break the seal
b/n the reservoir and your palm.  If there is pressure release, then you
have  HG leak.

Also, how long is the system staying pressurized?

Hope this helps,

-Justin

> Message: 1
> Date: Sat, 13 Oct 2012 21:26:34 +0100
> From: "Keith" <spotatashleys at hotmail.com>
> To: <urq at audifans.com>
> Subject: [urq] Cooling System question
> Message-ID: <BAY162-ds762FBF1E33B2E7E5213A2BB730 at phx.gbl>
> Content-Type: text/plain;       charset="utf-8"
>
> Evening All,
> I have some curious goings-on with my quattros cooling system. On occasion
> but not always there are one or two drops of coolant on the garage floor.
> The system does indeed lose a little, but so little as to be unable to
> trace the source. The running temperature is absolutely normal but the
> cooling system remains pressurised even when the engine has cooled right
> down. The engine runs fine.  I have searched on line for possible causes of
> the system remaining pressurised, some suggest a leaking head gasket.
> Obviously I do not want to remove this just to look and there are no other
> signs that I am aware of to suggest HG failure. I will be surprised and not
> a little disappointed if the HG is failing because the block was Wills
> ringed when I built it (10yrs ago though) to ensure a good seal around each
> cylinder and I don;t thrash it (in fact my friend ridicule my mechanical
> sympathy for my car!)
> I guess the question is: should I be concerned? Are there any tests I
> could do to confirm/deny HG failure given the current minimal outward
> symptoms? The amount of residual pressure in the system when cold is what
> concerns me the most though.
> Any ideas/suggestions gratefully received (as always).
> Regards
> Keith
>
> ?87 WR
>
> ------------------------------
>
> Message: 2
> Date: Sat, 13 Oct 2012 16:50:47 -0400
> From: "Chris Miller" <c1j1miller at aol.com>
> To: "'Keith'" <spotatashleys at hotmail.com>, <urq at audifans.com>
> Subject: Re: [urq] Cooling System question
> Message-ID: <000001cda984$6c510a40$44f31ec0$@com>
> Content-Type: text/plain;       charset="utf-8"
>
> I'd replace the cooling overflow bottle cap if you are concerned about
> pressure in the system; I believe that is the pressure relief valve in the
> cap.
>
> Easy ways to test for the head gasket leak (into the combustion chamber)
> include checking the plugs; the really clean cylinder may be leaking; also
> there are test strips you can use in the coolant to see if there are
> combustion gasses present.
>
> As for possible leaks:
>
> If it is leaking to the outside of the engine, not into the cylinders, I
> think you'd see a stain on the block.   Pull the lower engine cover and see.
>
> The later cars came with an after run electric cooling pump, I believe;
> not sure when that started.  They are plastic and can crack and leak.  Do
> not check them when hot as they can break open and douse you and cause a
> severe burn.  Similarly the control valve for the heater core is plastic
> and can crack.
>
> Another possible spot for a leak is the water pump; sometimes they seep
> but it would be difficult to see with the belt guards in place.
>
> There is also a small tube across the front of the block, behind the inner
> belt guard against the block.  On my 20v motor, it has a rubber hose on
> each end; I think that is the water return feed from the turbo.  The feed
> is below the turbo off the block.
>
> Chris
>
> -----Original Message-----
> From: urq-bounces at audifans.com [mailto:urq-bounces at audifans.com] On
> Behalf Of Keith
> Sent: Saturday, October 13, 2012 4:27 PM
> To: urq at audifans.com
> Subject: [urq] Cooling System question
>
> Evening All,
> I have some curious goings-on with my quattros cooling system. On occasion
> but not always there are one or two drops of coolant on the garage floor.
> The system does indeed lose a little, but so little as to be unable to
> trace the source. The running temperature is absolutely normal but the
> cooling system remains pressurised even when the engine has cooled right
> down. The engine runs fine.  I have searched on line for possible causes of
> the system remaining pressurised, some suggest a leaking head gasket.
> Obviously I do not want to remove this just to look and there are no other
> signs that I am aware of to suggest HG failure. I will be surprised and not
> a little disappointed if the HG is failing because the block was Wills
> ringed when I built it (10yrs ago though) to ensure a good seal around each
> cylinder and I don;t thrash it (in fact my friend ridicule my mechanical
> sympathy for my car!) I guess the question is: should I be concerned? Are
> there any tests I could do to confi
>  rm/deny HG failure given the current minimal outward symptoms? The amount
> of residual pressure in the system when cold is what concerns me the most
> though.
> Any ideas/suggestions gratefully received (as always).
> Regards
> Keith
>
> ?87 WR
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> ------------------------------
>
> Message: 3
> Date: Sun, 14 Oct 2012 16:51:06 +0200
> From: "Patrick Carlier" <p.carlier at pandora.be>
> To: "Keith" <spotatashleys at hotmail.com>,        <urq at audifans.com>
> Subject: Re: [urq] Cooling System question
> Message-ID: <000b01cdaa1b$572f77e0$c300a8c0 at PATRICKBE20CAB>
> Content-Type: text/plain; format=flowed; charset="utf-8";
>         reply-type=original
>
> Keith ,
>
> You ought to get some of these test rods
> for hydrocarbons in the coolant . Its cheap and it
> will tell you if the head/ headgasket is leaking or not .
>
> A crude test to the headgasket is to warm up the engine with the coolant
> tank cap cap removed .
> A leaking headgasket will cause "air" bubbles in the coolant wich can
> be observed in the tank .
> They usually occur if you revv the engine to say 3000 rpm just before
> the radiator fan kicks in .
>
> You do have the right coolant , with raised boiling point I hope .
> Plain water or ordinary anti freeze coolant will not do on an urq .
>
> I also advice you to check the sensor that operates the fan .
> It's located on the bottom of the radiator .
> They're known to fail , and if the fan doesn't kick in , pressure will rise
> eventuallly .
>
> Good luck
>
> Pat
>
>
>
>
>
>
> ----- Original Message -----
> From: "Keith" <spotatashleys at hotmail.com>
> To: <urq at audifans.com>
> Sent: Saturday, October 13, 2012 10:26 PM
> Subject: [urq] Cooling System question
>
>
> > Evening All,
> > I have some curious goings-on with my quattros cooling system. On
> occasion
> > but not always there are one or two drops of coolant on the garage floor.
> > The system does indeed lose a little, but so little as to be unable to
> > trace the source. The running temperature is absolutely normal but the
> > cooling system remains pressurised even when the engine has cooled right
> > down. The engine runs fine.  I have searched on line for possible causes
> > of the system remaining pressurised, some suggest a leaking head gasket.
> > Obviously I do not want to remove this just to look and there are no
> other
> > signs that I am aware of to suggest HG failure. I will be surprised and
> > not a little disappointed if the HG is failing because the block was
> Wills
> > ringed when I built it (10yrs ago though) to ensure a good seal around
> > each cylinder and I don;t thrash it (in fact my friend ridicule my
> > mechanical sympathy for my car!)
> > I guess the question is: should I be concerned? Are there any tests I
> > could do to confirm/deny HG failure given the current minimal outward
> > symptoms? The amount of residual pressure in the system when cold is what
> > concerns me the most though.
> > Any ideas/suggestions gratefully received (as always).
> > Regards
> > Keith
> >
> > ?87 WR
> > _______________________________________________
> > Audifans urq mailing list
> > Manage your list connection:
> http://www.audifans.com/mailman/listinfo/urq
> > http://www.audifans.com/kb/List_information
> >
> > Pictures/Polls/Database at:
> http://autos.groups.yahoo.com/group/urquattro/
> >
> >
>
>
>
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>
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