[urq] Cooling System question- update

Tue Oct 23 04:08:22 PDT 2012

Phil,

I think this is what has happened to my WX.  She's weeping coolant off the
bottom of the exhaust manifold outlet it cylinder one.  Is it repairable or
does it require a replacement head?

Cheers,
Tom
On Oct 23, 2012 6:36 AM, "Phil Payne" <phil at isham-research.co.uk> wrote:

> Don't be too quick to assume it's the head gasket.  I've seen similar
> symptoms on several occasions caused by a perforation between the head
> water
> jacket and #1 inlet chamber.
>
> -----Original Message-----
> From: urq-bounces at audifans.com [mailto:urq-bounces at audifans.com] On Behalf
> Of Keith
> Sent: 22 October 2012 21:09
> To: urq at audifans.com
> Subject: Re: [urq] Cooling System question- update
>
> I don't think there is any doubt now. I went for a short trip to town and
> when I got to town (2 miles) the system was under great pressure. I let it
> cool and then drove home and once it had cooled down again I removed the
> plugs. 2,3,4 & 5 were fine - a little darker than I expected but it had
> just
> run on rich mixture. No1 plug was black and was really hard to remove due
> to
> what I found was rust on the thread. Shining a torch down the plug holes -
> revealed 2,3,4 & 5 had a blackish oily film on their surface but nothing
> too
> bad but No1 was shiny clean aluminium and looked a bit damp. I rolled up a
> piece of newspaper and pushed it in to the plug hole and soaked up some
> drops of liquid which smelled of antifreeze. There's no water in the oil,
> so
> I'm hoping I've caught all this in time but I guess I'll only know if there
> has been any damage once I strip it down - which I'll start next week once
> I've bought all I need for head gasket change (gaskets, bolts and beer). It
> will be interesting to find what has caused this. The engine is 10 years
> and
> 33000 miles old and despite this trouble runs fine. I reckon the recent and
> occasional odd spots of coolant on the garage floor were overflow from the
> header tank when the pressure got too great. I guess I have been lucky the
> heater matrix didn't fail.
> So, off the road for the winter now.......
> Thanks to all who answered my appeal for thoughts and guidance. No doubt
> I'll be back on the list if I encounter bad things!
> Thanks again and all the best
>
> Keith
>
> '87 WR in darkest foggy Worcestershire.
>
>
>
> -----Original Message-----
> From: Chris Miller
> Sent: Saturday, October 13, 2012 9:50 PM
> To: 'Keith' ; urq at audifans.com
> Subject: RE: [urq] Cooling System question
>
> 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 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
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