COLD S4

[s42k5b]

My heat will only stay warm for about 3 minutes and then the air becomes cooler. My car warms up proprerly, but when driving on the highway my water temp drops to the cold side about a 1/4 of the way to cold. I was wondering if it is ok to be driving it like that?I'm not sure if this is my coolant temp switch or thermostat. Flushed the coolant twice in the past 3 weeks due to a broken T that exploded by my reservoir tank.

[golfman44]

well, i would be much more concerned if it was an overheating issue...i think its something to look into, but keeping an engine cool usually isnt bad ;)

[BastardS4]

uh. its not great either.

[Sleeeper X]

My heat will only stay warm for about 3 minutes and then the air becomes cooler. My car warms up proprerly, but when driving on the highway my water temp drops to the cold side about a 1/4 of the way to cold. I was wondering if it is ok to be driving it like that?I'm not sure if this is my coolant temp switch or thermostat. Flushed the coolant twice in the past 3 weeks due to a broken T that exploded by my reservoir tank.

Hey, you going tonight?

[JDM EJ1 95]

thermostat is stuck open

[RedRocketS4]

did you do a t-belt job yet? if so, did you replace the thermostat?

[Tugboatguy]

It's your thermostat , and no Don't drive like that.

[cavlovic]

I have a similar problem. My water temp gauge climbs and drops. I guess it's thermostat problem...

Is my car running a bit slower when the gauge drops, or is it just my imagination?

p.s. My B5 S4 has 54k miles on it so no TB job has been done yet. A couple more thousands and I'll turn it to a dealer for the job.

[s42k5b]

Hey, you going tonight?

yupp you?

[s42k5b]

did you do a t-belt job yet? if so, did you replace the thermostat?

T Stat was replaced when timing belt was done.

[Rated S]

Sounds like it broke again.

[AudiSportB5S4]

yeah a cold engine will usually run rich causing shitty gas mileage and a cold motor doesnt run as efficiently as a warm one. i had the same problem with mine i would notice it on long trips prior to the Tbelt job..

[MacDaddy]

mine did the exact same, you need a new t-stat.

you can replace it without removing the belt, its not that hard, but it requires cranking the engine over by hand and shuffling the timing belt away from the block about 3/8" to give you just enough clearance to remove the housing and t-stat.

[dennisS4]

I have a similar problem. My water temp gauge climbs and drops. I guess it's thermostat problem...

Is my car running a bit slower when the gauge drops, or is it just my imagination?

p.s. My B5 S4 has 54k miles on it so no TB job has been done yet. A couple more thousands and I'll turn it to a dealer for the job.

You need to get the timing belt service done either 105,000 miles(recommended by audi, should be 85,000) or 6 years.
Better get that done soon.

[InLoveWithMyS4]

I have a similar problem. My water temp gauge climbs and drops. I guess it's thermostat problem...

Is my car running a bit slower when the gauge drops, or is it just my imagination?

p.s. My B5 S4 has 54k miles on it so no TB job has been done yet. A couple more thousands and I'll turn it to a dealer for the job.

I would not wait any longer. Your rubber is 8-9 years old, rendering it drier and more brittle than I'd be comfortable with. IIRC, Audi does state 7 years as the limit...

[Muck_and_Grind]

dont be a puss. who needs a heater anyways. oh wait i live in california.