Strange coolant temp guage movement - 98 A4 V6
 

This just started happening. On cold mornings the engine takes a while
to warm up - say 4-5 minutes after driving. Used to be much quicker.

Now the really odd thing is the water temp gauge (no degrees, just
marks) used to be just to the left (cool side) of top dead center when
warm. Now, it will go straight up, then in a few minutes, actually
fall to almost where the "C" is and then move up again. Would a bad
thermostat cause the needle to swing wildly like this? I originally
thought it was the thermostat until the gauge did this strange
maneuver and now I am wondering if is the sensor out of whack.

The oil temp seems to be fine.

98 Audi A4 V6, 2.8l Quattro, 5spd. US model.
--
___________________________
Make your PC part of the largest computer in the world
See http://www.seti-inst.edu/setiathome.html for more info

Re: Strange coolant temp guage movement - 98 A4 V6
 

Could be the Tstat or sensor but it could also be low coolant and a bubble in
the system.

Ed H. wrote:
> This just started happening. On cold mornings the engine takes a while
> to warm up - say 4-5 minutes after driving. Used to be much quicker.
>
> Now the really odd thing is the water temp gauge (no degrees, just
> marks) used to be just to the left (cool side) of top dead center when
> warm. Now, it will go straight up, then in a few minutes, actually
> fall to almost where the "C" is and then move up again. Would a bad
> thermostat cause the needle to swing wildly like this? I originally
> thought it was the thermostat until the gauge did this strange
> maneuver and now I am wondering if is the sensor out of whack.
>
> The oil temp seems to be fine.
>
> 98 Audi A4 V6, 2.8l Quattro, 5spd. US model.

Re: Strange coolant temp guage movement - 98 A4 V6
 

Could be the Tstat or sensor but it could also be low coolant and a bubble in
the system.

Ed H. wrote:
> This just started happening. On cold mornings the engine takes a while
> to warm up - say 4-5 minutes after driving. Used to be much quicker.
>
> Now the really odd thing is the water temp gauge (no degrees, just
> marks) used to be just to the left (cool side) of top dead center when
> warm. Now, it will go straight up, then in a few minutes, actually
> fall to almost where the "C" is and then move up again. Would a bad
> thermostat cause the needle to swing wildly like this? I originally
> thought it was the thermostat until the gauge did this strange
> maneuver and now I am wondering if is the sensor out of whack.
>
> The oil temp seems to be fine.
>
> 98 Audi A4 V6, 2.8l Quattro, 5spd. US model.

Re: Strange coolant temp guage movement - 98 A4 V6
 

Could be the Tstat or sensor but it could also be low coolant and a bubble in
the system.

Ed H. wrote:
> This just started happening. On cold mornings the engine takes a while
> to warm up - say 4-5 minutes after driving. Used to be much quicker.
>
> Now the really odd thing is the water temp gauge (no degrees, just
> marks) used to be just to the left (cool side) of top dead center when
> warm. Now, it will go straight up, then in a few minutes, actually
> fall to almost where the "C" is and then move up again. Would a bad
> thermostat cause the needle to swing wildly like this? I originally
> thought it was the thermostat until the gauge did this strange
> maneuver and now I am wondering if is the sensor out of whack.
>
> The oil temp seems to be fine.
>
> 98 Audi A4 V6, 2.8l Quattro, 5spd. US model.

Re: Strange coolant temp guage movement - 98 A4 V6
 

Tony <tonyjnospam@nospamvisi.com> wrote:

>Could be the Tstat or sensor but it could also be low coolant and a bubble in
>the system.

I considered low coolant, but the overflow is well above the "Min"
line. I guess I'll take it in early next week to get checked out.
Thanks.

>Ed H. wrote:
>> This just started happening. On cold mornings the engine takes a while
>> to warm up - say 4-5 minutes after driving. Used to be much quicker.
>>
>> Now the really odd thing is the water temp gauge (no degrees, just
>> marks) used to be just to the left (cool side) of top dead center when
>> warm. Now, it will go straight up, then in a few minutes, actually
>> fall to almost where the "C" is and then move up again. Would a bad
>> thermostat cause the needle to swing wildly like this? I originally
>> thought it was the thermostat until the gauge did this strange
>> maneuver and now I am wondering if is the sensor out of whack.
>>
>> The oil temp seems to be fine.
>>
>> 98 Audi A4 V6, 2.8l Quattro, 5spd. US model.

--
___________________________
Make your PC part of the largest computer in the world
See http://www.seti-inst.edu/setiathome.html for more info

Re: Strange coolant temp guage movement - 98 A4 V6
 

Tony <tonyjnospam@nospamvisi.com> wrote:

>Could be the Tstat or sensor but it could also be low coolant and a bubble in
>the system.

I considered low coolant, but the overflow is well above the "Min"
line. I guess I'll take it in early next week to get checked out.
Thanks.

>Ed H. wrote:
>> This just started happening. On cold mornings the engine takes a while
>> to warm up - say 4-5 minutes after driving. Used to be much quicker.
>>
>> Now the really odd thing is the water temp gauge (no degrees, just
>> marks) used to be just to the left (cool side) of top dead center when
>> warm. Now, it will go straight up, then in a few minutes, actually
>> fall to almost where the "C" is and then move up again. Would a bad
>> thermostat cause the needle to swing wildly like this? I originally
>> thought it was the thermostat until the gauge did this strange
>> maneuver and now I am wondering if is the sensor out of whack.
>>
>> The oil temp seems to be fine.
>>
>> 98 Audi A4 V6, 2.8l Quattro, 5spd. US model.

--
___________________________
Make your PC part of the largest computer in the world
See http://www.seti-inst.edu/setiathome.html for more info

Re: Strange coolant temp guage movement - 98 A4 V6
 

Tony <tonyjnospam@nospamvisi.com> wrote:

>Could be the Tstat or sensor but it could also be low coolant and a bubble in
>the system.

I considered low coolant, but the overflow is well above the "Min"
line. I guess I'll take it in early next week to get checked out.
Thanks.

>Ed H. wrote:
>> This just started happening. On cold mornings the engine takes a while
>> to warm up - say 4-5 minutes after driving. Used to be much quicker.
>>
>> Now the really odd thing is the water temp gauge (no degrees, just
>> marks) used to be just to the left (cool side) of top dead center when
>> warm. Now, it will go straight up, then in a few minutes, actually
>> fall to almost where the "C" is and then move up again. Would a bad
>> thermostat cause the needle to swing wildly like this? I originally
>> thought it was the thermostat until the gauge did this strange
>> maneuver and now I am wondering if is the sensor out of whack.
>>
>> The oil temp seems to be fine.
>>
>> 98 Audi A4 V6, 2.8l Quattro, 5spd. US model.

--
___________________________
Make your PC part of the largest computer in the world
See http://www.seti-inst.edu/setiathome.html for more info

Re: Strange coolant temp guage movement - 98 A4 V6
 

It's probably the sensor. I had to have mine replaced on the same car -
around $200 at the dealer IIRC. Thermostats usually fail by sticking in some
position so the behavior you describe is unlikely. .

Re: Strange coolant temp guage movement - 98 A4 V6
 

It's probably the sensor. I had to have mine replaced on the same car -
around $200 at the dealer IIRC. Thermostats usually fail by sticking in some
position so the behavior you describe is unlikely. .

Re: Strange coolant temp guage movement - 98 A4 V6
 

It's probably the sensor. I had to have mine replaced on the same car -
around $200 at the dealer IIRC. Thermostats usually fail by sticking in some
position so the behavior you describe is unlikely. .