1995 Audi 90 2.8l engine temperature low

Ok, before you all say that I need a new thermostat, I've been there.
:-)

The engine temperature guage seems to regulate to the first, thin white
line at about 1/4 on the guage. There is a thick white line
just below half way up the guage where I would expect the needle to settle.
The needle only gets there on warm days in the summer
or if I let the car idle stopped for some long period of time. Somewhat
farther up the guage(just above half guage) the fans turn on,
as I would expect also. The heater blows very slightly warm air if the
outside temp is below, say, 45 degrees.... unless I let the car
sit idling long enough to get the gauge up to or past the thick white line I
mentioned before. Then the heat seems to work fine. If the outside
temp is below 40 or so, the "Heat" makes my feed cold!

If I'm moving, even at slow speeds, the gauge settles back the the thin
white line at about 1/4 again.

Also, the oil temp only just comes off the cold mark (60degrees C) to
the first white mark at about 1/6 the guage. The engine has
an oil cooler so I wouldn't expect the oil to get much above the coolant
temp.

All indications are that the engine is not getting to full operating
temperature. I've replaced the thermostat twice, once because it really
failed. I've installed the 97 degree C thermostat, not the 87. And still,
very low heater output, and the needle stays at about 1/4 on the gauge.
There is no indication on the gauge as to what the temperature value is.

Any ideas?

I am having almost the same problem with my 97 A6. I have replaced the
thermostat 3 times. The coolant temp is the same as yours but my oil temp is
where it is supposed to be. I was told by one garage that the previous
owner had used an additive to seal up a leak in the system and now the whole
thing is clogged and needs to be replaced(about $700). I haven't gotten a
second opinion on it yet, though.
"Gene Buckwalter" > wrote in message
...
>
> Ok, before you all say that I need a new thermostat, I've been there.
> :-)
>
> The engine temperature guage seems to regulate to the first, thin
white
> line at about 1/4 on the guage. There is a thick white line
> just below half way up the guage where I would expect the needle to
settle.
> The needle only gets there on warm days in the summer
> or if I let the car idle stopped for some long period of time. Somewhat
> farther up the guage(just above half guage) the fans turn on,
> as I would expect also. The heater blows very slightly warm air if the
> outside temp is below, say, 45 degrees.... unless I let the car
> sit idling long enough to get the gauge up to or past the thick white line
I
> mentioned before. Then the heat seems to work fine. If the outside
> temp is below 40 or so, the "Heat" makes my feed cold!
>
> If I'm moving, even at slow speeds, the gauge settles back the the
thin
> white line at about 1/4 again.
>
> Also, the oil temp only just comes off the cold mark (60degrees C) to
> the first white mark at about 1/6 the guage. The engine has
> an oil cooler so I wouldn't expect the oil to get much above the coolant
> temp.
>
> All indications are that the engine is not getting to full operating
> temperature. I've replaced the thermostat twice, once because it really
> failed. I've installed the 97 degree C thermostat, not the 87. And
still,
> very low heater output, and the needle stays at about 1/4 on the gauge.
> There is no indication on the gauge as to what the temperature value is.
>
> Any ideas?
>
>

It sounds like your diagnosis is correct - the engine is not getting up to
temperature. The way the radiator fan works sounds correct when you let it idle
to get it warm.

Th only thing that strikes me is that it might be possible to install the T stat
upside down so that it opens too easily or maybe a gasket to seal it into place
is missing.

Tony

Gene Buckwalter wrote:

> Ok, before you all say that I need a new thermostat, I've been there.
> :-)
>
> The engine temperature guage seems to regulate to the first, thin white
> line at about 1/4 on the guage. There is a thick white line
> just below half way up the guage where I would expect the needle to settle.
> The needle only gets there on warm days in the summer
> or if I let the car idle stopped for some long period of time. Somewhat
> farther up the guage(just above half guage) the fans turn on,
> as I would expect also. The heater blows very slightly warm air if the
> outside temp is below, say, 45 degrees.... unless I let the car
> sit idling long enough to get the gauge up to or past the thick white line I
> mentioned before. Then the heat seems to work fine. If the outside
> temp is below 40 or so, the "Heat" makes my feed cold!
>
> If I'm moving, even at slow speeds, the gauge settles back the the thin
> white line at about 1/4 again.
>
> Also, the oil temp only just comes off the cold mark (60degrees C) to
> the first white mark at about 1/6 the guage. The engine has
> an oil cooler so I wouldn't expect the oil to get much above the coolant
> temp.
>
> All indications are that the engine is not getting to full operating
> temperature. I've replaced the thermostat twice, once because it really
> failed. I've installed the 97 degree C thermostat, not the 87. And still,
> very low heater output, and the needle stays at about 1/4 on the gauge.
> There is no indication on the gauge as to what the temperature value is.
>
> Any ideas?
>
>

Sounds like your shop is looking to pick up some more money. I doubt very much
that anything is 'clogged' up in your system just because the PO used BarsAll or
Stop-Leak.

My son has a '98 A4 2.8 Tip. His heater core started a small leak that caused
his windshield to fog badly. I can't remember the name by the stop leak product
that we used but it looked like silver flakes in a small plastic tube. Stopped
the leak for the last two years with no other problems.

His car gets to temperature at the middle line and stays there like the needle
was nailed in place in all ambient conditions.

Tony

Archangel wrote:

> I am having almost the same problem with my 97 A6. I have replaced the
> thermostat 3 times. The coolant temp is the same as yours but my oil temp is
> where it is supposed to be. I was told by one garage that the previous
> owner had used an additive to seal up a leak in the system and now the whole
> thing is clogged and needs to be replaced(about $700). I haven't gotten a
> second opinion on it yet, though.
> "Gene Buckwalter" > wrote in message
> ...
>
>> Ok, before you all say that I need a new thermostat, I've been there.
>>:-)
>>
>> The engine temperature guage seems to regulate to the first, thin
>
> white
>
>>line at about 1/4 on the guage. There is a thick white line
>>just below half way up the guage where I would expect the needle to
>
> settle.
>
>>The needle only gets there on warm days in the summer
>>or if I let the car idle stopped for some long period of time. Somewhat
>>farther up the guage(just above half guage) the fans turn on,
>>as I would expect also. The heater blows very slightly warm air if the
>>outside temp is below, say, 45 degrees.... unless I let the car
>>sit idling long enough to get the gauge up to or past the thick white line
>
> I
>
>>mentioned before. Then the heat seems to work fine. If the outside
>>temp is below 40 or so, the "Heat" makes my feed cold!
>>
>> If I'm moving, even at slow speeds, the gauge settles back the the
>
> thin
>
>>white line at about 1/4 again.
>>
>> Also, the oil temp only just comes off the cold mark (60degrees C) to
>>the first white mark at about 1/6 the guage. The engine has
>>an oil cooler so I wouldn't expect the oil to get much above the coolant
>>temp.
>>
>> All indications are that the engine is not getting to full operating
>>temperature. I've replaced the thermostat twice, once because it really
>>failed. I've installed the 97 degree C thermostat, not the 87. And
>
> still,
>
>>very low heater output, and the needle stays at about 1/4 on the gauge.
>>There is no indication on the gauge as to what the temperature value is.
>>
>> Any ideas?
>>
>>
>
>
>

Arch,
I agree with Tony, if the system was clogged you'd expect a less efficient
heat exchange and an overheating engine.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

"Tony" > wrote in message
...
> Sounds like your shop is looking to pick up some more money. I doubt very
much
> that anything is 'clogged' up in your system just because the PO used
BarsAll or
> Stop-Leak.
>
> My son has a '98 A4 2.8 Tip. His heater core started a small leak that
caused
> his windshield to fog badly. I can't remember the name by the stop leak
product
> that we used but it looked like silver flakes in a small plastic tube.
Stopped
> the leak for the last two years with no other problems.
>
> His car gets to temperature at the middle line and stays there like the
needle
> was nailed in place in all ambient conditions.
>
> Tony
>
> Archangel wrote:
>
> > I am having almost the same problem with my 97 A6. I have replaced the
> > thermostat 3 times. The coolant temp is the same as yours but my oil
temp is
> > where it is supposed to be. I was told by one garage that the previous
> > owner had used an additive to seal up a leak in the system and now the
whole
> > thing is clogged and needs to be replaced(about $700). I haven't gotten
a
> > second opinion on it yet, though.
> > "Gene Buckwalter" > wrote in message
> > ...
> >
> >> Ok, before you all say that I need a new thermostat, I've been
there.
> >>:-)
> >>
> >> The engine temperature guage seems to regulate to the first, thin
> >
> > white
> >
> >>line at about 1/4 on the guage. There is a thick white line
> >>just below half way up the guage where I would expect the needle to
> >
> > settle.
> >
> >>The needle only gets there on warm days in the summer
> >>or if I let the car idle stopped for some long period of time. Somewhat
> >>farther up the guage(just above half guage) the fans turn on,
> >>as I would expect also. The heater blows very slightly warm air if the
> >>outside temp is below, say, 45 degrees.... unless I let the car
> >>sit idling long enough to get the gauge up to or past the thick white
line
> >
> > I
> >
> >>mentioned before. Then the heat seems to work fine. If the outside
> >>temp is below 40 or so, the "Heat" makes my feed cold!
> >>
> >> If I'm moving, even at slow speeds, the gauge settles back the the
> >
> > thin
> >
> >>white line at about 1/4 again.
> >>
> >> Also, the oil temp only just comes off the cold mark (60degrees C)
to
> >>the first white mark at about 1/6 the guage. The engine has
> >>an oil cooler so I wouldn't expect the oil to get much above the coolant
> >>temp.
> >>
> >> All indications are that the engine is not getting to full operating
> >>temperature. I've replaced the thermostat twice, once because it really
> >>failed. I've installed the 97 degree C thermostat, not the 87. And
> >
> > still,
> >
> >>very low heater output, and the needle stays at about 1/4 on the gauge.
> >>There is no indication on the gauge as to what the temperature value is.
> >>
> >> Any ideas?
> >>
> >>
> >
> >
> >

I wondered about the shops diagnosis also that's why I'm getting a second
opinion. The second shop did a flush of the system when they did the timing
belt/water pump and now we have some heat although not as hot as it should
be unless we're moving. As far as the stop leak not causing the problem...
well it was not just for a small leak, it turned out that the head gasket
was cracked and that's how they tried to fix it. Maybe they used allot of
the stuff?


"Tony" > wrote in message
...
> Sounds like your shop is looking to pick up some more money. I doubt very
much
> that anything is 'clogged' up in your system just because the PO used
BarsAll or
> Stop-Leak.
>
> My son has a '98 A4 2.8 Tip. His heater core started a small leak that
caused
> his windshield to fog badly. I can't remember the name by the stop leak
product
> that we used but it looked like silver flakes in a small plastic tube.
Stopped
> the leak for the last two years with no other problems.
>
> His car gets to temperature at the middle line and stays there like the
needle
> was nailed in place in all ambient conditions.
>
> Tony
>
> Archangel wrote:
>
> > I am having almost the same problem with my 97 A6. I have replaced the
> > thermostat 3 times. The coolant temp is the same as yours but my oil
temp is
> > where it is supposed to be. I was told by one garage that the previous
> > owner had used an additive to seal up a leak in the system and now the
whole
> > thing is clogged and needs to be replaced(about $700). I haven't gotten
a
> > second opinion on it yet, though.
> > "Gene Buckwalter" > wrote in message
> > ...
> >
> >> Ok, before you all say that I need a new thermostat, I've been
there.
> >>:-)
> >>
> >> The engine temperature guage seems to regulate to the first, thin
> >
> > white
> >
> >>line at about 1/4 on the guage. There is a thick white line
> >>just below half way up the guage where I would expect the needle to
> >
> > settle.
> >
> >>The needle only gets there on warm days in the summer
> >>or if I let the car idle stopped for some long period of time. Somewhat
> >>farther up the guage(just above half guage) the fans turn on,
> >>as I would expect also. The heater blows very slightly warm air if the
> >>outside temp is below, say, 45 degrees.... unless I let the car
> >>sit idling long enough to get the gauge up to or past the thick white
line
> >
> > I
> >
> >>mentioned before. Then the heat seems to work fine. If the outside
> >>temp is below 40 or so, the "Heat" makes my feed cold!
> >>
> >> If I'm moving, even at slow speeds, the gauge settles back the the
> >
> > thin
> >
> >>white line at about 1/4 again.
> >>
> >> Also, the oil temp only just comes off the cold mark (60degrees C)
to
> >>the first white mark at about 1/6 the guage. The engine has
> >>an oil cooler so I wouldn't expect the oil to get much above the coolant
> >>temp.
> >>
> >> All indications are that the engine is not getting to full operating
> >>temperature. I've replaced the thermostat twice, once because it really
> >>failed. I've installed the 97 degree C thermostat, not the 87. And
> >
> > still,
> >
> >>very low heater output, and the needle stays at about 1/4 on the gauge.
> >>There is no indication on the gauge as to what the temperature value is.
> >>
> >> Any ideas?
> >>
> >>
> >
> >
> >

Gene,
I'd get a thermometer and check the temp of the fluid running into the rad.
With a 97c thermostat, the fluid should circulate in the block only for a
longer period, and the regular oil temp should raise as well. The coolant
temperature gauge is on the outside of the t-stat, so it is more a gauge of
the temperature of the fluid in the rad than the engine, and if the t-stat
is holding the temp in, then you'd expect the oil temp to go way up. I've
heard of new t-stats malfunctioning - I checked the last one I put in the
5ktq on the stove before I put it in - had to use cooking oil as the water
was boiling below the opening point (not that I live on a significant
mountain, or anything). Tony is about right - there has to be heated
coolant bypassing the thermostat.
On the heater issue, have you checked that the cabin heating system is
operating correctly? My '87 5ktq had only unheated air out the vents all
summer - turns out that the servo motor ist kaput and wouldn't pull the
bowden cable that changes the air supply from outside to from the heater
core. I found the servo pack behind the glovebox and manually rotated the
servo link to heat - now all I'll have to do is change it back in the spring
(take THAT, "climate control system"!) There's a discussion about CC
problems on Audifans today - if your system has the "fault codes", on the
Type 44 system channel 8 and 9 should be within 3 units of each other if the
servo is working well.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

"Gene Buckwalter" > wrote in message
...
>
> Ok, before you all say that I need a new thermostat, I've been there.
> :-)
>
> The engine temperature guage seems to regulate to the first, thin
white
> line at about 1/4 on the guage. There is a thick white line
> just below half way up the guage where I would expect the needle to
settle.
> The needle only gets there on warm days in the summer
> or if I let the car idle stopped for some long period of time. Somewhat
> farther up the guage(just above half guage) the fans turn on,
> as I would expect also. The heater blows very slightly warm air if the
> outside temp is below, say, 45 degrees.... unless I let the car
> sit idling long enough to get the gauge up to or past the thick white line
I
> mentioned before. Then the heat seems to work fine. If the outside
> temp is below 40 or so, the "Heat" makes my feed cold!
>
> If I'm moving, even at slow speeds, the gauge settles back the the
thin
> white line at about 1/4 again.
>
> Also, the oil temp only just comes off the cold mark (60degrees C) to
> the first white mark at about 1/6 the guage. The engine has
> an oil cooler so I wouldn't expect the oil to get much above the coolant
> temp.
>
> All indications are that the engine is not getting to full operating
> temperature. I've replaced the thermostat twice, once because it really
> failed. I've installed the 97 degree C thermostat, not the 87. And
still,
> very low heater output, and the needle stays at about 1/4 on the gauge.
> There is no indication on the gauge as to what the temperature value is.
>
> Any ideas?
>
>

Arch,
I had a similar thing happen to me except in the opposite direction - the
car ran hot since the day I got it - the dealer looked at it, flushed the
system, told me that it was probably plugged by rust & debris from the
engine. A short time later it began to seriously overheat and I found out
the head gasket was toast (heat reason #1). Had the hg replaced and they
filled it with water/froze overnight in a cold snap/overheated on the
highway next morning (AARRRGHHH!) and then the plastic end tank gave up and
barfed all over the parking lot at work. When I was disposing of the rad I
pulled the remains of the plastic tanks off - the rubber gasket on the side
with all of the hose ports to the engine was broken (old break) between the
hot and cold sides - short circuiting the rad (heat reason #2). The used
brass Modine I put in works like a charm now.
It seems that "it's plugged" seems like an easy diagnosis for an older
system that isn't working as it should. Take a look into the climate
control system, especially the heater valve at the back of the engine. With
all sorts of vacuum leaks, stripped servo gears, worn fan brushes - makes me
wish the CC system was as simple as the one in my DKW - 2 levers: hot/cold
and Winter/Summer.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

"Archangel" > wrote in message
news:NPgyd.9644$fe5.7131@trndny06...
> I wondered about the shops diagnosis also that's why I'm getting a second
> opinion. The second shop did a flush of the system when they did the
timing
> belt/water pump and now we have some heat although not as hot as it should
> be unless we're moving. As far as the stop leak not causing the
problem...
> well it was not just for a small leak, it turned out that the head gasket
> was cracked and that's how they tried to fix it. Maybe they used allot of
> the stuff?
>
>
> "Tony" > wrote in message
> ...
> > Sounds like your shop is looking to pick up some more money. I doubt
very
> much
> > that anything is 'clogged' up in your system just because the PO used
> BarsAll or
> > Stop-Leak.
> >
> > My son has a '98 A4 2.8 Tip. His heater core started a small leak that
> caused
> > his windshield to fog badly. I can't remember the name by the stop leak
> product
> > that we used but it looked like silver flakes in a small plastic tube.
> Stopped
> > the leak for the last two years with no other problems.
> >
> > His car gets to temperature at the middle line and stays there like the
> needle
> > was nailed in place in all ambient conditions.
> >
> > Tony
> >
> > Archangel wrote:
> >
> > > I am having almost the same problem with my 97 A6. I have replaced the
> > > thermostat 3 times. The coolant temp is the same as yours but my oil
> temp is
> > > where it is supposed to be. I was told by one garage that the
previous
> > > owner had used an additive to seal up a leak in the system and now the
> whole
> > > thing is clogged and needs to be replaced(about $700). I haven't
gotten
> a
> > > second opinion on it yet, though.
> > > "Gene Buckwalter" > wrote in message
> > > ...
> > >
> > >> Ok, before you all say that I need a new thermostat, I've been
> there.
> > >>:-)
> > >>
> > >> The engine temperature guage seems to regulate to the first, thin
> > >
> > > white
> > >
> > >>line at about 1/4 on the guage. There is a thick white line
> > >>just below half way up the guage where I would expect the needle to
> > >
> > > settle.
> > >
> > >>The needle only gets there on warm days in the summer
> > >>or if I let the car idle stopped for some long period of time.
Somewhat
> > >>farther up the guage(just above half guage) the fans turn on,
> > >>as I would expect also. The heater blows very slightly warm air if
the
> > >>outside temp is below, say, 45 degrees.... unless I let the car
> > >>sit idling long enough to get the gauge up to or past the thick white
> line
> > >
> > > I
> > >
> > >>mentioned before. Then the heat seems to work fine. If the outside
> > >>temp is below 40 or so, the "Heat" makes my feed cold!
> > >>
> > >> If I'm moving, even at slow speeds, the gauge settles back the the
> > >
> > > thin
> > >
> > >>white line at about 1/4 again.
> > >>
> > >> Also, the oil temp only just comes off the cold mark (60degrees C)
> to
> > >>the first white mark at about 1/6 the guage. The engine has
> > >>an oil cooler so I wouldn't expect the oil to get much above the
coolant
> > >>temp.
> > >>
> > >> All indications are that the engine is not getting to full
operating
> > >>temperature. I've replaced the thermostat twice, once because it
really
> > >>failed. I've installed the 97 degree C thermostat, not the 87. And
> > >
> > > still,
> > >
> > >>very low heater output, and the needle stays at about 1/4 on the
gauge.
> > >>There is no indication on the gauge as to what the temperature value
is.
> > >>
> > >> Any ideas?
> > >>
> > >>
> > >
> > >
> > >
>
>

The heating system seems to function as well as it can with the engine
coolant temp being low....if that's really the case.

Last night I put a therocouple on the temp sensor in the pipe that comes
out of he rear of the passenger side head. That seemed to read about
70C when the dash needle was where it normally rests. Then I moved the
thermocouple to the radiator, right where the heated water enters it. That
read about 85C or so a few minutes later, when the temp had risen above its
normal operating temp.

Anyway, as you mentioned, I also beleive the only way for the temp to be
low is either a bad run of thermostats or something wrong with
the way it's installed. Somehow, heated coolant is getting to the radiator
to lose its heat.

Is it possible that the coolant configuration on this engine is
different from what the orientation instructions say that come with the
thermostat? The thermostat in backwards may cause this sort of problem.

I soon need to fix an oil leak on the front of the engine so I'll be
removing the timing belt and such anyway. I plan to take a
very carefull look at the coolant direction and the orientation of the
t-stat and replace it for good measure.


Gene


"Steve Sears" > wrote in message
. ..
> Gene,
> I'd get a thermometer and check the temp of the fluid running into the
rad.
> With a 97c thermostat, the fluid should circulate in the block only for a
> longer period, and the regular oil temp should raise as well. The coolant
> temperature gauge is on the outside of the t-stat, so it is more a gauge
of
> the temperature of the fluid in the rad than the engine, and if the t-stat
> is holding the temp in, then you'd expect the oil temp to go way up. I've
> heard of new t-stats malfunctioning - I checked the last one I put in the
> 5ktq on the stove before I put it in - had to use cooking oil as the water
> was boiling below the opening point (not that I live on a significant
> mountain, or anything). Tony is about right - there has to be heated
> coolant bypassing the thermostat.
> On the heater issue, have you checked that the cabin heating system is
> operating correctly? My '87 5ktq had only unheated air out the vents all
> summer - turns out that the servo motor ist kaput and wouldn't pull the
> bowden cable that changes the air supply from outside to from the heater
> core. I found the servo pack behind the glovebox and manually rotated the
> servo link to heat - now all I'll have to do is change it back in the
spring
> (take THAT, "climate control system"!) There's a discussion about CC
> problems on Audifans today - if your system has the "fault codes", on the
> Type 44 system channel 8 and 9 should be within 3 units of each other if
the
> servo is working well.
> Cheers!
> Steve Sears
> 1987 Audi 5kTQ
> 1980 Audi 5k
> 1962 and '64 Auto Union DKW Junior deLuxes
> (SPAM Blocker NOTE: Remove SHOES to reply)
>
> "Gene Buckwalter" > wrote in message
> ...
> >
> > Ok, before you all say that I need a new thermostat, I've been
there.
> > :-)
> >
> > The engine temperature guage seems to regulate to the first, thin
> white
> > line at about 1/4 on the guage. There is a thick white line
> > just below half way up the guage where I would expect the needle to
> settle.
> > The needle only gets there on warm days in the summer
> > or if I let the car idle stopped for some long period of time. Somewhat
> > farther up the guage(just above half guage) the fans turn on,
> > as I would expect also. The heater blows very slightly warm air if the
> > outside temp is below, say, 45 degrees.... unless I let the car
> > sit idling long enough to get the gauge up to or past the thick white
line
> I
> > mentioned before. Then the heat seems to work fine. If the outside
> > temp is below 40 or so, the "Heat" makes my feed cold!
> >
> > If I'm moving, even at slow speeds, the gauge settles back the the
> thin
> > white line at about 1/4 again.
> >
> > Also, the oil temp only just comes off the cold mark (60degrees C)
to
> > the first white mark at about 1/6 the guage. The engine has
> > an oil cooler so I wouldn't expect the oil to get much above the coolant
> > temp.
> >
> > All indications are that the engine is not getting to full operating
> > temperature. I've replaced the thermostat twice, once because it really
> > failed. I've installed the 97 degree C thermostat, not the 87. And
> still,
> > very low heater output, and the needle stays at about 1/4 on the gauge.
> > There is no indication on the gauge as to what the temperature value is.
> >
> > Any ideas?
> >
> >
>
>

You should also check to see if the Tstat is supposed to have one of those 'O'
ring seals that snap on its edge. If it is, and it isn't there, you would get a
lot of flow around the sides.

Tony

Gene Buckwalter wrote:

> The heating system seems to function as well as it can with the engine
> coolant temp being low....if that's really the case.
>
> Last night I put a therocouple on the temp sensor in the pipe that comes
> out of he rear of the passenger side head. That seemed to read about
> 70C when the dash needle was where it normally rests. Then I moved the
> thermocouple to the radiator, right where the heated water enters it. That
> read about 85C or so a few minutes later, when the temp had risen above its
> normal operating temp.
>
> Anyway, as you mentioned, I also beleive the only way for the temp to be
> low is either a bad run of thermostats or something wrong with
> the way it's installed. Somehow, heated coolant is getting to the radiator
> to lose its heat.
>
> Is it possible that the coolant configuration on this engine is
> different from what the orientation instructions say that come with the
> thermostat? The thermostat in backwards may cause this sort of problem.
>
> I soon need to fix an oil leak on the front of the engine so I'll be
> removing the timing belt and such anyway. I plan to take a
> very carefull look at the coolant direction and the orientation of the
> t-stat and replace it for good measure.
>
>
> Gene
>
>
> "Steve Sears" > wrote in message
> . ..
>
>>Gene,
>>I'd get a thermometer and check the temp of the fluid running into the
>
> rad.
>
>>With a 97c thermostat, the fluid should circulate in the block only for a
>>longer period, and the regular oil temp should raise as well. The coolant
>>temperature gauge is on the outside of the t-stat, so it is more a gauge
>
> of
>
>>the temperature of the fluid in the rad than the engine, and if the t-stat
>>is holding the temp in, then you'd expect the oil temp to go way up. I've
>>heard of new t-stats malfunctioning - I checked the last one I put in the
>>5ktq on the stove before I put it in - had to use cooking oil as the water
>>was boiling below the opening point (not that I live on a significant
>>mountain, or anything). Tony is about right - there has to be heated
>>coolant bypassing the thermostat.
>>On the heater issue, have you checked that the cabin heating system is
>>operating correctly? My '87 5ktq had only unheated air out the vents all
>>summer - turns out that the servo motor ist kaput and wouldn't pull the
>>bowden cable that changes the air supply from outside to from the heater
>>core. I found the servo pack behind the glovebox and manually rotated the
>>servo link to heat - now all I'll have to do is change it back in the
>
> spring
>
>>(take THAT, "climate control system"!) There's a discussion about CC
>>problems on Audifans today - if your system has the "fault codes", on the
>>Type 44 system channel 8 and 9 should be within 3 units of each other if
>
> the
>
>>servo is working well.
>>Cheers!
>>Steve Sears
>>1987 Audi 5kTQ
>>1980 Audi 5k
>>1962 and '64 Auto Union DKW Junior deLuxes
>>(SPAM Blocker NOTE: Remove SHOES to reply)
>>
>>"Gene Buckwalter" > wrote in message
...
>>
>>> Ok, before you all say that I need a new thermostat, I've been
>
> there.
>
>>>:-)
>>>
>>> The engine temperature guage seems to regulate to the first, thin
>>
>>white
>>
>>>line at about 1/4 on the guage. There is a thick white line
>>>just below half way up the guage where I would expect the needle to
>>
>>settle.
>>
>>>The needle only gets there on warm days in the summer
>>>or if I let the car idle stopped for some long period of time. Somewhat
>>>farther up the guage(just above half guage) the fans turn on,
>>>as I would expect also. The heater blows very slightly warm air if the
>>>outside temp is below, say, 45 degrees.... unless I let the car
>>>sit idling long enough to get the gauge up to or past the thick white
>
> line
>
>>I
>>
>>>mentioned before. Then the heat seems to work fine. If the outside
>>>temp is below 40 or so, the "Heat" makes my feed cold!
>>>
>>> If I'm moving, even at slow speeds, the gauge settles back the the
>>
>>thin
>>
>>>white line at about 1/4 again.
>>>
>>> Also, the oil temp only just comes off the cold mark (60degrees C)
>
> to
>
>>>the first white mark at about 1/6 the guage. The engine has
>>>an oil cooler so I wouldn't expect the oil to get much above the coolant
>>>temp.
>>>
>>> All indications are that the engine is not getting to full operating
>>>temperature. I've replaced the thermostat twice, once because it really
>>>failed. I've installed the 97 degree C thermostat, not the 87. And
>>
>>still,
>>
>>>very low heater output, and the needle stays at about 1/4 on the gauge.
>>>There is no indication on the gauge as to what the temperature value is.
>>>
>>> Any ideas?
>>>
>>>
>>
>>
>
>