Water temperature / pump

[Shytot]

I have a Mk III Ibiza and recently the dial has started to fluctuate and is not maintaining its 90 degree constant. This drop only happens when freewheeling whilst in any gear . Temperature is maintained in neutral and in gear????? or indeed sat at the lights. Would the engine management system pick this up if it gets any worse? The lowest its gone too after cruising around is 75 degrees but then as soon as the engine is under load it returns to 90. Car has done 80k . Is this something anyone has heard of . Is it the aircon seal or is my water pump on its way out .

Many thanks as always

 

[ibizacupra]

maybe just the sender..
water pumps are known to fail. plastic impellor on them comes undone from drive spindle.. Usual symptum is idle temp (on gauge) is ok.. 90'C, but drive it and its rises quickly.

vag-com fault code download might have a stored implausable signal/intermittant against coolant sensor maybe.

 

[Shytot]

thanks for the quick reply Bill. The gauge isnt going over 90 degrees thankfully and the fans work but when I am coasting. for eg , going downhill whilst in gear the temperature starts to drop . if I take it out of gear, it goes back up again after a minute or so to 90. Could this still be the sender or the impeller . I dont think my aircon is working either as I tried to put it on and the AC wouldnt stay illuminated not.

stumped

 

[ibizacupra]

its probably too cold for a/c to come on anyhow... <5'C it does'nt work.

 

[adam1]

mine is the same had the car 6 months brought it private and it started to do it every now and then. now its stuck at 0 and only jumps to 90' very rarely and then only stays there for a matter of seconds. Mines going to the garage soon so any advice would be good so i can point them in the right direction thanks