Should the coolant temp gauge stay at 90c on A4 2.0TDI B8.5

[Leicesterdave]

New car to me, 13 plate- was on the motorway and it stayed at 90c but then when I'm on normal city roads it went to down a bit..... Does that sound normal?

[eybic]

Doesn't sound ridiculous to me although the 90 it points to is likely anywhere between 80 & 100 as they're not that accurate.

[Yertis]

I think every Audi I've had has stayed at 90 – in fact I was musing the other day that its about the only thing that hasn't changed between my first Audi 80 and the new A4 I've got at the moment. That and the cost of main dealer servicing.

[Scabutz]

Every Audi I have had it says dead on 90. Some cars have a dead zone where ti will show 90 even if its somewhere between 80-100 but I didn't think Audis did

[gregpot2000]

Generally normal....both my B8 and B8.5 were exactly the same, these engines run very cold, changing the thermostat may improve things, but more than likely will make no different.

thanks

[Leicesterdave]

gregpot2000 said:

Generally normal....both my B8 and B8.5 were exactly the same, these engines run very cold, changing the thermostat may improve things, but more than likely will make no different.

thanks

Thanks- strange though and the wording in the manual doesn't indicate whether it's normal or not. It just states that Diesel engine do run very efficiently....

[anonymous-user]

My B7 stays at 90 when warmed up, did have a thermostat that wouldn't close fully and this was reflected in the gauge with much longer warm up time.

[Condi]

90 is normal.

The thermostats do sometimes go on them, but the temp will struggle to reach 90 at all, and as soon as you reduce the revs to idle it quickly falls away again.

[Leicesterdave]

Condi said:

90 is normal.

The thermostats do sometimes go on them, but the temp will struggle to reach 90 at all, and as soon as you reduce the revs to idle it quickly falls away again.

Are you saying that mine is normal behaviour? IE happy to stay at 90c on motorway but temp falling when driving in town?

[Griff74]

I've not seen a modern car drop below 90 once warmed up even in winter, thermostat stuck fully open or missing maybe?

[PartTimeShedMan]

VAG group cars certainly used to stay on 90. My 1.8T displays 90 upto around 115 - then shoots up to the red. (I drove it with the a failing water pump and Torque hooked up showing the true reading from the ECU).

[Leicesterdave]

Is there a way of finding a definite answer on this?

[Griff74]

Leicesterdave said:

Is there a way of finding a definite answer on this?

Check\replace the thermostat.

[blueg33]

I have had 3 audi's and we currently have a 2 year old Octavia, the temp is pretty constant at 90 in these cars unless under reall stress like heavily laden on a hot day going up a steep hill after a long fast run.

OBD shows the temps remain pretty stable too.

For what its worth my daughters fiesta is similarly stable and even the evora unless I have been driving very spiritedly and then hit station traffic,.

[Leicesterdave]

Mechanic says it’s totally normal as well as Audi specialist...
The diesel ultras do this as they do run so very efficiently....

So sod knows

[cuprabob]

Modern VAG cars have a "corrected" coolant temperature gauge which will display 90 when the actual coolant temperature is between 75 and 105 degrees. It can be changed to display actual real time temperature using VCDS.