Help needed! 90 20v running cold with water temp. light on!

[psiconauta911]

Hi all.

My 90 20v as been runing cold for a while although I´ve changed the thermostat twice, it gets up to 90ºc in traffic but comes down to 70ºc when the road opens up. everything seems ok, the ventilator works as it should and the coolant level is ok but recently I´m having a water temp/level warning light a minute or so after first start of the day that stays on all day!

Any help is much appreciated and thank you all in advance.

[steve briance]

What brand of multi function temperature sensor have you got? I would predict it was a Mahle.... Ive just been having problems with my gauge and overheat warning. The MFTS was to blame. A JP group brand sender gave the best reading but an alarm. The mahle gave no alarm but variable reading with speed (presumably airflow related) and the meyle brand sensor gave no alarm but over read on the gauge by a lot! I failed to find a brand that worked properly.

[psiconauta911]

I think mine it´s still the original one!

[John.]

Maybe worth checking the connector of the MFTS ?

[psiconauta911]

I´ll check the MFTS and the connector tomorrow! Thanks

[newsh]

A good double check.
If you have Vagcom then check the temp with that, it’s in measuring block 1.
This is the temp the ECU is seeing from the sender on the back of the cylinder head.

[psiconauta911]

Thank you Newsh.

No Vagcom but I´ll get it done just in case it´s the culprit!