overheating and other issues

**jasst** · 16-06-2019,07:07 PM

My 2006 2.0 fsi est was overheating when stuck in traffic, I have replaced the water pump, both thermostats and both temp senders, before I did this work it struggled to get to full temp, which it now does, and runs at an indicated 90 degrees until I get stuck in traffic, when it rises to 110+ and I have to put the heater on max to bring it back down, what should I look for next?
Also have another issue, when I did the timing belt the other day, the battery was disconnected for about 10 days, since reconnecting it will not store my average fuel consumption, and every time I switch engine off, it starts at Zero again, and there is no option 2 on the mfd to display average mpg.

**jmurray01** · 16-06-2019,08:14 PM

Have you checked that the radiator fan is cutting in when it gets to/exceeds 90 degrees? Sounds as if it isn't running which will cause it to overheat unless you put the heater on.

**Crasher** · 16-06-2019,08:37 PM

If it is showing 110 on the gauge it is a LOT hotter in reality. A few days ago I was monitoring a VAG cars warm up and I got the feeling it was getting hot but the gauge said 90.... when I checked in the measuring blocks it was 108 so I turned it off. The main cooling fan, which contains the controller, had failed.

**jasst** · 16-06-2019,09:12 PM

When I did the thermostats I ran it up, and tried various things like air con on or off, sometimes the fans would run sometimes not, is there any way of testing the fan controller/

**jmurray01** · 16-06-2019,09:34 PM

The fan should always run with the A/C on so don't let that fool you into thinking it is running under normal conditions. What I would do is take it for a drive then park up so as to provoke an overheat situation and see if the fan is running without the A/C on.

**jasst** · 16-06-2019,09:57 PM

When I tested it, sometimes the fan would not run even with the air con on.
When it got hot in traffic again on sat I parked up and lifted the bonnet to check, and the fan was not running.
Another thing, just been looking at new fan units on the likes of *******, have got what I think is the correct part no, but even then there seem to be different power outputs even for the same part no! (confused)

**Crasher** · 16-06-2019,10:24 PM

You can run the fans in engine and HVAC output tests using a suitable diagnostic system where you can also accurately watch the engine temperatures at a couple of different points in some cases.

**jasst** · 17-06-2019,12:51 PM

Just been out and run it up to temp, aircon on full, no fans running at all, wouldn't go above indicated 90 in this crap weather, got vcds but still learning how to use it.

**Crasher** · 17-06-2019,01:24 PM

I have a TTS in and the gauge stays dead on 90 but the computer was showing 117 at the head sensor but 95 at the rad outlet sensor and it was boiling over yet no warning, indication or fans even! I think the water pump is at fault but we don't have time until next week to do it. The thing is, why these daft temp gauges, why don't they tell you the engine is too hot? The Ibiza Bocanegra we did the head on a few weeks back has no temperature gauge, no level warning (even though the bottle has the fitting) and was getting a bit hot and no warning light! Bloody negligent...

**jasst** · 17-06-2019,05:30 PM

I had vcds connected when I ran it up to temp, manged to get it to show temp and watched it rise to 89 when gauge said 90, so think that's ok, apparently the fan controller is built in, does anyone know if its part of the main fan (big one) or somewhere else, trying to decide what I need to replace in that department.