Correct Temp?

[RossB]

Basic Question, but what is the correct coolant temperature for a 2.0L?
Mine seems to run at 90 deg but has gone down to 70 at times, I note that the Bentley says the fan comes in at 91-105 and I would think that this would be the upper end of the range.
A bit of work now if needed might save me big $ later.
Car was seviced (major) in march.
Ross.

[SoVeReIgN]

Should be 90 - Thermostat most likely gone if it is dropping on the open road and sitting correctly in traffic.

[RossB]

Thanks,
It was a very cold night when it dipped and it happily sits on 90 when it's in traffic. Just one more thing to add to the "must check that" list.

Ross.

[anarchycamp]

Should be 90 - Thermostat most likely gone if it is dropping on the open road and sitting correctly in traffic.

Noticed my MkII drops right down on open road and in traffic sits mid point in traffic....time to replace thermostat perhaps?

[MattyT]

My VR6 seems to sit at 90 no matter what im doing.

[wayz]

Why would the thermostat be faulty if the reading drops during open road driving?
I would've thought that cooling would be more efficient when the car is driving along the open road? Just a thought, dont know if thats right though?

[Whist]

Thats what I would think as well, Mine goes back to 70 when on the highway but rises to 90 around town, however if its a hot day it can go up to 90 on the highway.

[daveshep]

Vr6

yeah my VR6 runs so cold when on the open road that you'd think the temperature gauge wasnt working... when sitting still or driving slowly in traffic the temperature comes up to the middle of the gauge, which makes me think the thermostats stuck open.

gonna be a messy job changing the thermostat but - i've had the coolant out of the car a few times and it never gets any more fun. anyone got tips so i can reuse the coolant? i've got a sweet metal crackpipe so draining the coolant will be a little easier...

[VW Convert]

Why would the thermostat be faulty if the reading drops during open road driving?
I would've thought that cooling would be more efficient when the car is driving along the open road? Just a thought, dont know if thats right though?

Hi wayz,

I'm no expert on VW's and operating temps, I do know my Jetta runs on 90 at all times. What is important is understanding the purpose of a thermostat and that is to keep the engine as close to it's ideal operating temperature as possible by restricting or allowing the flow of coolant. The fact that your temperature drops during open road driving MAY and I emphasise MAY indicate your thermostat is not resticting flow when it should be therefore allowing the temperature to drop below the ideal temperature. Cooler is not necessarily better and running too cool will have a detrimental effect on the engine.

I hope that helps in some way.

Cheers

George

[wayz]

Ahh... Yep, point taken!
I see the point about running too cool, but is 70ish too cool? The last thing i want is any 'detrimental' things happening to my car

Hi wayz,

I'm no expert on VW's and operating temps, I do know my Jetta runs on 90 at all times. What is important is understanding the purpose of a thermostat and that is to keep the engine as close to it's ideal operating temperature as possible by restricting or allowing the flow of coolant. The fact that your temperature drops during open road driving MAY and I emphasise MAY indicate your thermostat is not resticting flow when it should be therefore allowing the temperature to drop below the ideal temperature. Cooler is not necessarily better and running too cool will have a detrimental effect on the engine.

I hope that helps in some way.

Cheers

George

[VW Convert]

Ahh... Yep, point taken!
I see the point about running too cool, but is 70ish too cool? The last thing i want is any 'detrimental' things happening to my car

Wish I could answer but I'm beyond the boundaries of my specific knowledge of VW's!

Someone out there must know!


Cheers

George

[craig_the_german]

Temperature

Hi everyone,

I own a 1.6L Mk IV with a coolant temp problem. My gauge can be running at 90deg all day and then without warning, start to drop and sometimes reaches the bottom of the gauge, then again without warning, start to climb again. It will at times hover somewhere inbetween.

I have been told by a couple of VW dealers that the problem is with the temperature sensor/sender and this is a really common problem. One dealler had 30 temperature senser/senders on the shelf. I will be changing mine this arvo and i'll see what happens.

If the gauge is moving erratically, it maybe the same issue with the Mk 3s as it is with the Mk IVs

[craig_the_german]

The result

Hi everyone,

I replaced the temperature sensor Friday afternoon and the gauge is now steady at 85-90deg. Seems that was the problem.

[BigD]

Basic Question, but what is the correct coolant temperature for a 2.0L?
Mine seems to run at 90 deg but has gone down to 70 at times, I note that the Bentley says the fan comes in at 91-105 and I would think that this would be the upper end of the range.
A bit of work now if needed might save me big $ later.
Car was seviced (major) in march.
Ross.

Ross

Short answer is temp should be on 90deg constant before you are able to be adventerous with the right pedal, if you drive the car hard either side of this range your engine wears alot more and will eventually fail if not rectifyed and addressed.

noteworthy to add the engine is more efficent at normal operating temp.

Sounds like thermostat is stuck open and the pentosin and fans are doing there job by not allowing the water to heat above 105.

if the car takes ages to warm to 90 then fluctuates during motion (winter esp)then its the culprit for sure.

when the temp falls below 90 take it easy on the right pedal until you get it checked out.

this is my first post here and I did how the info on these pages will save me time and money by getting info from others

[RossB]

Thanks BigD, and everyone,

My first thought was the themostat but some vehicle types have their own little quirks. Most of the driving is short trips (second car) and it does take a little while to warm up, so looks like a job for next weekend.

RB