Weird one that is doing my nut in Help please.

[Azman]

Evening guys,

Here we go,

Right, To set the pic.

Driving along normally temp guage reads approx 1/4 (say 75deg) if not a littl less in this weather. Stop driving for traffic say and the temp goes up as normal and expected, fan comes on etc etc, all normal.

Anyone else get this. I can't believe that the engine runs at such a temp that it the rad is not running at 90deg even after a 40mile drive.

So today, changed the themostat just in case. refilled with coolant and water, ran it on the drive for about 30 mins, watching the guage and also kept checking the lower rad pipe (just behind the metal housing for the themostat) eventually as expected full temp water at that part of the pipe and the overflow(to the top of the tank) was flowing a bit of water, again as I would have expected, bled it as normal, hot temp from the fans inside the car etc etc etc.

All good, went for a little drie and again the temp would not budge over the 1/4mark while driving along, only when in traffic.

got home lifted the bonnet and felt the bottom pipe again - COLD??????

Let it run and hey presto hot and water flowing again as i am guessing the stat opened....

So the question is - IS THIS NORMAL??? Doesn't feel it to me. surely the themostat should be open once th car has hit full temp, doesn't seem right that the thing closes again when driving....

THought please ladies and gents. really doing my head in..

Oh and for all intensive purposes the car is driving normal just a little bit of hunting for revs at idle (even after cleaning the ISV)

Cheers

Aaron

[Error404]

IIRC 1/4 on the temp gauge is actually around 87deg which would be the stat opening temp anyway mate - all the 7As seem to register about thisd temp on normal cruising, not sure about 3B / ABYs though

you sure the system is bled properly?

[Azman]

So why would the bottom pipe be cold and I mean stone cold, very little warmth to it??? Which way round does the water pump pull the water ? From bottom of rad into engine or top of rad into engine??

[Error404]

in at the top out at the bottom

[Azman]

So the bottom would be cooler anyway so that pipe would be cold..... Strange must be a really good rad to cool like it is

[mcandmar]

IIRC 1/4 on the temp gauge is actually around 87deg which would be the stat opening temp anyway mate - all the 7As seem to register about thisd temp on normal cruising, not sure about 3B / ABYs though

you sure the system is bled properly?

My 7A is the exact same, will only get upto 90 sitting in traffic. The S2/S4 run hotter and sit just below 90 on the move and will move a couple of notches past 90 when sitting in traffic.

[Azman]

@maca, driving the S2 which is why I am alittle unnerved over it

[Jamo]

search MTFS

ECU uses different sensor to the dash. You need vagcom to show what temp the ecu is reading from the cylinder head sensor. If it's correct your MTFS is duff or could be affect by the wind chill that was suggested across the forum.

[johne]

Sounds like normal behaviour. If you search for Jamo or Jase's post of a picture of the temp gauge with the actual temps on it 1/4 reading will be not far off 87 degrees. Couple that with fact that many thermostats are often a degree or two lower on closing even right out the box and it all adds up to normal behavior. It's the thermostat closing temperature that dictate's the reading when you're just cruising along.

Finding a 88 degree thermostat -QH did one - will help pull the reading up a bit.

John

[Azman]

Cheers for the info got an 88deg stat in as of today last one was 87deg. will have to test the MFTS then...... cheers

[newsh]

Check to see if your MFTS has a rubber boot, if not it gets cooled by the breeze in this sort of weather and reads low You can zip-tie a bit of silicon pipe round it to sheild it if the boot is missing.

[Jamo]

search MTFS

ECU uses different sensor to the dash. You need vagcom to show what temp the ecu is reading from the cylinder head sensor. If it's correct your MTFS is duff or could be affect by the wind chill that was suggested across the forum.

See here http://www.s2forum.com/forum/showthread.php?t=13984

[Azman]

oooo forgot to say also have no afterrun ?????? What to check for that on???

[Azman]

As it sounds from those threads (cheers jamo) that the temp is okay. will still get my mits on a new MFTS anyway just to doubly sure.

Best place to get one???

[Error404]

I got one a little while ago of Pete at QC for about £50