Faulty themostat?

[JimVR6 10]

Just wondering if anybody can shed any light;

 

Oil temps are a nice and steady 92-100, although the water temp gauge doesn't go much above 70. Heater works fine. Sender at fault, stuck thermostat? Needle does move, though only marginally varies in traffic.

 

Thank you.

[fla 9]

could be a stuck thermostat although I've replaced mine twice and flushed the system with VWs recommended orange flush liquid but its still the same, sadly. My temps are similar to yours.

[VW_OwneR_85 1]

if it is stuck open that just means that your cooling system will take longer to get up to temperature, think of it like a domestic central heating system with all the radiators turned off ,the boiler {engine} will heat up a lot quicker then with all the rads on but it will eventually get up to temp with or without the rads, does it take awhile to register any heat? idd say the senders at fault seeing as your oil temps are a lot higher,

[Jim Bowen 1]

My temp gauge reads the same. Replaced everything including the entire engine and still does it.

 

I wonder if its the actual dash gauge. Noticed lots of people with the same issue.

[JimVR6 10]

I'm not too worried, oil temps are spot on and nothing else seems out of the ordinary. Heater works as quick as any I've seen. I'll clean the sender contacts up tomorrow as it looks very grubby.

[davidwort 0]

I've tried a number of genuine vag senders and they do vary, best way to check is with an infra red thermometer, then you can be sure of head outlet temp, rad input and exit temp and temp at the actual sender.

[JimVR6 10]

Well both hoses seem to get hot simultaneously and gradually after about 3 or 4 minutes. So I can only assume if it IS stuck, at least its open. Tested the heater last night and the hot air was appearing after a similar time. So I might leave it for now, going to do a coolant change anyway.

[Critical_Mass 10]

Personally i think this is just a characteristic of old clocks. Happened to mine, despite changing everything from thermostat, temp sender, chip in the instruments and the guage. Get vagcom plugged in and read the water temp off the ECU.. if its as expected then its just the guage.

[JimVR6 10]

Taken it out again this evening and it rose to 85 at one point, then dropped just hovering above 70. Meh.