What symptoms would a stuck thermostat cause?

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What symptoms would a stuck theromstat cause in a standard carb 1.6
engine?  What long term damage would this cause if it was left like
this with a stuck thermostat?  Would a stuck thermostat explain quite
lot drop of power, have to rev it to death to get a high speed or
maintain one? eg at traffic lights you have to keep reving it
otherwise will cut out.

Re: What symptoms would a stuck thermostat cause?
Andrew Marshall <A Marshall> decided to enlighten our sheltered souls with a
rant as follows
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normal symptoms of a knackered thermostat are either overheating, or
overcooling. If it's ye olde thermostat the temp gauge should tell you in a
matter of seconds.


--
Pete M

Alfa 164 TS,
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Re: What symptoms would a stuck thermostat cause?

"Andrew Marshall" <A Marshall> wrote in message
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The symptom of a knackered thermostat is overheating.

The symptoms you describe are those of a knackered head gasket. A
compression test will prove or disprove this.

Of course the head gasket may have failed due to the overheating caused by a
knackered thermostat.

Steve



Re: What symptoms would a stuck thermostat cause?
On Fri, 5 Mar 2004 23:59:19 -0000, "shazzbat"

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Well the temperature gauge gas never registered as over heating.  It
hasn't been reaching where it should be. Which would seem like
'overcooling'. Engine always seems to be running as if the choke is on
all the time.

Wouldnt a failed head gasket mean significant loss of coolant in the
radiator? As that hasn't happened.



Re: What symptoms would a stuck thermostat cause?
On Sat, 06 Mar 2004 03:39:08 +0000, Andrew Marshall <A Marshall>
wrote:

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More like the distributor vacuum advance is stuck or diaphragm or hose
has a leak.  Pull hose that leads from distributor to carb off at carb
end.  Wipe clean and suck on it.  If you can create suction the hose
and diaphragm are ok.  If you can suck air it's leaking somewhere,
check hose first and if ok replace vacuum capsule.  Beware, main
dealers tend to sell compete distributors, go to a good motor factor
(yellow pages or yell), else you are going to tour the scrap yards but
the diaphragms on the cars there are all dud or about to fail too.  If
you can create suction you should hear a soft clunk from the
distributor as you release it - that's the advance plate returning
under spring action.  If no clunk take the rotor cap off and check the
plate with the arm attached rotates when you push the arm into the
vacuum capsule.  A squirt of WD40 should help.

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Are you checking radiator top tank or just the expansion tank?  Temp
gauge should come up to midway in about 2 miles of steady 30mph
driving.  If it reads low it's either a stuck open stat or the sensor
is in air.

--
Peter Hill
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Re: What symptoms would a stuck thermostat cause?

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I checked the top tank. It needed about half a litre of topping up.
But is months since I last topped it up.  Has been needing this kind
of topping up for a long time.  i dont know why it loses half a litre
over a few months of constant use, but apart from that no major
problems.

Are these repairs likely to be costly?  How much labour time.  Its the
labour that bumps up the cost a lot, even if the parts that are needed
are cheap.

Re: What symptoms would a stuck thermostat cause?
On Sat, 06 Mar 2004 17:05:39 +0000, Andrew Marshall <A Marshall>
wrote:

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Some systems require that bleed points are opened.  French cars can
have up to 3 bleed points, most have 2.  Some are simple pressure caps
like tyre valves others are hex cap screws with copper washers.  Some
are easy to see like the Pug 1.1 where one is on the heater feed and
one on the stat housing.  Some are almost impossible to get at like
the BX16 where one is hidden at the back of the engine below the
exhaust manifold.  Have to be filled though an extension on the rad
filler point to get the head of water needed to drive all the air out.

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Small leak on a hose somewhere - one of the small ones that feeds the
heater or part of the manifold etc would be a trace of blue scale from
antifreeze at the leak.  Cracked head?  Need to have a cylinder
leakage test and cooling system pressure test to find out for sure
where the water is going and why.  Compression test just won't show
this slow leakage.

--
Peter Hill
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Re: What symptoms would a stuck thermostat cause?

"Andrew Marshall" <A Marshall> wrote in message
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If your 1.6 has an water heated auto choke, and the thermostat is stuck wide
open- the overcooling could result in the auto choke getting only cold water
so never opening- and causing a rich mixture which would give you a fast
idle, poor mpg at the least. Some auto chokes lock the 2nd barrel shut
whilst in use- which would restrict power to about 50%.

Long term damage of running very cool and / or with the choke stuck on would
be bore wash and knackered rings leading to poor compressions and sump oil
dilution, and in its worst possible case bearing failure because the oil has
been thinned by fuel.

A total cut when it approcahes idle, rather than a splutter splutter stall
would be a blocked idle circuit in the carb.

Tim..



Re: What symptoms would a stuck thermostat cause?
On Sat, 6 Mar 2004 09:15:53 +0000 (UTC), " Tim \(Remove NOSPAM."

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It is more of a splutter splutter stall. Can be tricky when braking in
traffic as you have to quickly touch break then apply revs again.

MPG does seem to be poor.  It does seem to have started leaking more
oil than normal.  Would this indicate anything?

Re: What symptoms would a stuck thermostat cause?
On Fri, 05 Mar 2004 23:38:46 +0000, Andrew Marshall <A Marshall>
wrote:

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Exactly what 1.6 is it?

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Peter Hill
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