2003 Jetta 1.8T overheating

[dawnnewsome3]

Hello , I have a friend that has a 03 jetta with 66,000 miles and it is running hot . Sitting in the drive it will stay at 190 degree's with the AC on , main fan running second ac fan never comes on , but you take it up the road and it will go up to 240 and some times drop instantly back to 190 but most the time it just stay hot . Hot air out of the heater , no leaks , radiator filll tank full , upper hose hot and under pressure . I have no idea where the fan relays are to check them . No check lights at all Alternator reads 14.06 at idle 13.85 at battery and it seems to drag a little when cranking battery reads 12.56 and holds . Any idea where to start wooking for the problem ? maybe fan , relay , temp sensor , Thanks for any help .

[veedubmechanic]

replace the coolant temperature sensor

do a search

[dawnnewsome3]

Thanks , I did a web search and the water pump, something about the plastic impeller blades braking came up many times seems that at idle and low rpm it pumps through enough to cool but at speed and higher rpm it does not flow enough to cool right and when you let off the throttle the engine slows and the water flows so it cools again . Does this seem right , they say replace with one with a metal one . Any thoughts ? No codes or check lights .

[BEAVIS18]

Originally Posted by dawnnewsome3

Thanks , I did a web search and the water pump, something about the plastic impeller blades braking came up many times seems that at idle and low rpm it pumps through enough to cool but at speed and higher rpm it does not flow enough to cool right and when you let off the throttle the engine slows and the water flows so it cools again . Does this seem right , they say replace with one with a metal one . Any thoughts ? No codes or check lights .

yeah it sounnd's right my grilfriend has a 2000 jetta with the 2.0
and it's doing the same thing at idle it run's at 190 but when you
go to drive it will go to 260 fast

[veedubmechanic]

it does have the same symptoms but since you said the temp goes to 240 then instantls to 190 then back to 240 it would lead me to believe the ect is bad. Its 18.00 worth of parts and some coolant and its alot cheaper than 600 to have the waterpump replaced.

[dawnnewsome3]

Well was just able to check the fans and the one onthe drivers side is toast , getting voltage to it but the fan doesn't work . plan on replacing it and check it again back at temp and go from there . So hard to get any thing done with so many project in the works . Luckily my friend is in no hurry .

[veedubmechanic]

the fans are controlled by the fan module located under the batter (you have to look up from the ground its bolted upside down). Also check the fuses on top of the battery, common issue. Also check the resistance of the fan motor itsself, should be .2-.5ohm. if its ofl then replace the fan.