Cooling system problems?

[The_Laird]

Originally Posted by IT

haha. I too noted the overly detailed accuracy on his reporting...

Well, you've seen my fuel consumption log (still going strong with every fill up since I bought the car three and half years ago!), so you should expect a high degree of OCD in this as well!

[moltuae]

Originally Posted by The_Laird

Surely not! If you assume the 120 mark is the one before the red one (although it's not that clear) then the marks are as follows:
50 (marked on the dial)
63.33
76.66
90 (marked on the dial)
97.5
105
112.5
120 (marked on dial)

Given that the marks aren't equidistant, why would they choose such daft values to mark up? And why make the interval before 90 at 13.33 and afterwards 7.5?

Unless maybe it's simply 90, 100, 110, with 120 being the first of the last 3 thicker marks.

Not sure about the markings after 50 in that case though ... perhaps it goes 50, 60, 80, 90?

[mattylondon]

Having just quickly measured the angle between each marker, that 50c marking doesn't seem correct. 60 would fit better.

My guess is:
50 (marked on the dial)
70
80
90 (marked on the dial)
100
110
120 (marked on the dial)
125
130

[ainarssems]

On PF last 3 marks and number 120 is red as well

[Delboy]

The gauges are not linear, there are believe it or not maps for the gauges so the info fed to them gets displayed at the correct mark.

Only way to know for sure is stick VCDS on her and log it on your travels into work.

[awolfinsheepsclothes]

Mr Laird
Why not just use the secret HVAC codes it's 102 for coolant temp! Monitor it from cold feeling the top hose, to see when the stat opens. And when the fan switches on. You can also use a infrared temp gun (cheap nowadays) to check for hotspots in the rad.
Mine is at 90 most of the time I've only seen it to the next mark once on a very hot day for oldham 26+ degrees after spanking it then getting stuck in a traffic jam and I don't run a viscous fan. I just relie on the a/c fan.
Dave

[Mechcanico Lee]

From your diag i would say partially blocked radiator , at motorway speeds 80mph or so the engines not really working but you will have massive air flow coming through , town work stop start plodding along with little air flow , yes the fans can cut in but if a lot of the vanes are blocked up the fans just cannot dissipate the heat .

You can try to back flush the rad but in my experience its hard to clean down the vanes ,the water just takes the easiest path and goes down the clear vanes

Get a rad put on it and a genuine thermostat as a matter of course .

[The_Laird]

Originally Posted by Delboy

The gauges are not linear, there are believe it or not maps for the gauges so the info fed to them gets displayed at the correct mark.

Only way to know for sure is stick VCDS on her and log it on your travels into work.

I understand that they're not linear, but what I don't understand is why they mark the gauge up at intervals that are open to interpretation.

If this were my job, I'd either put 3 marks between 50 and 90 (60,70,80) or one (70). And between 90 and 120, just 2 (100 and 110, as it might be, depending on which mark is supposed to 120).

And I'd have made the last 2 marks (if they are, indeed, something over 120) a wider red bar.

What's so hard about that? Then the intervals would be obvious. What's the point of a gauge if you can't understand it? It might as well have 3 divisions marked in green, amber and red!

In the meantime, the car seems to be staying below 100C (or the mark after 90) and Scotland's summer (last Sunday to Tuesday lunchtime) appears to be over, so I'll be looking for a sensible-priced new radiator (any recommendations welcome).

[awolfinsheepsclothes]

No need for vagcom! just press recirculate and the up arrow on passenger side heating controls use the + to go to channel 102 and tells you the exact temp the sensor is reading. I've seen it at 98 degrees the Guage still displays 90.
They seem to do it, because everyone else does it! It makes your car look efficient, it looks like it warms up faster, engine temp stays rock steady and doesn't get hot in traffic.
You can either keep throwing expensive parts at it like a poor garage! Or workout the actual fault.
Dave

[The_Laird]

Originally Posted by awolfinsheepsclothes

No need for vagcom! just press recirculate and the up arrow on passenger side heating controls use the + to go to channel 102 and tells you the exact temp the sensor is reading. I've seen it at 98 degrees the Guage still displays 90.
They seem to do it, because everyone else does it! It makes your car look efficient, it looks like it warms up faster, engine temp stays rock steady and doesn't get hot in traffic.
You can either keep throwing expensive parts at it like a poor garage! Or workout the actual fault.
Dave

Thanks Dave, I'll give that a try at the weekend.