water temp/fuel gauge - possible problem (???)

[Critical_Mass 10]

Hi all,

 

Right leading off the WTD thread i started. I've been having fuel gauge reading issues and also water temp issues, I was thinking that it maybe the gauge. But after a bit of thinking im going to start looking else where.

 

Firstly the water temp issue. The needle on the water temp gauge never sits bang in the middle. It will take a while to move at all and when it does it will only go up to 70 even when the car has been running for miles. It will very rarely, if ever go over 70 degrees and when it does it wont go much over. Today i driving as normal and it went to its usual place of 70, i then got stuck in traffic and it went up to about 80 but no higher. It then dropped back to 70 once i got moving again. Now the oil temps are normal. I also plugged vagcom in and the temp read 96 degrees, the gauge was reading 70. Could it be one of the sensors on the front of the engine, seen as the ECU seems to be reading fine but the gauge is off?

 

Which sensor is which, is the blue temp sender for the ECU and the yellow for the gauges and fans, or the other way round?

 

Ok fuel problem. The gauge doesnt seem to have been right for ages. BUt tonight confirmed something was wrong as it was the first time in a while i'd filled the car right to the top :lol:. I filled the car until the nozzle clicked, which was 52.7 litres. Now i know the tank can hold 15 gallons, so that equates to 11.6 gallons. The needle also doesnt go right to the top but sits one line down from the max. So the tank looks like its short 1 gallon. Could this be the float in the tank, the sender or something else?

 

Sorry to go on a bit but i dont like to be vague in my threads.

 

Any help is much appreciate.

 

Gaz

[davidwort 0]

if both gauges play up then it can be the voltage regulator on the dash PCB, which can be replaced, this is certainly the case on the older style dash, not sure about the later ones.

[Critical_Mass 10]

if both gauges play up then it can be the voltage regulator on the dash PCB, which can be replaced, this is certainly the case on the older style dash, not sure about the later ones.

 

Cheers for the response David. Got a pic of the Voltage regulator? PCB?

[davidwort 0]

somewhere, it looks like a small flat 3 legged transistor about 1cm wide

 

ah, here we are:

vw_dash_voltage_stabaliser.gif[/attachment:9azkcg9o]

[Critical_Mass 10]

somewhere, it looks like a small flat 3 legged transistor about 1cm wide

 

ah, here we are:

vw_dash_voltage_stabaliser.gif[/attachment:1u063k6o]

 

Ah yes the stabaliser - just had that replaced and doesnt seem to have made much of a difference. Which leads me onto investigating the float or sender in the tank?

[Critical_Mass 10]

Anymore help guys/gals?

[Critical_Mass 10]

Anyone?

[DanVW 0]

Never had to do it on the C but if I was you I would be tempted to pull up the boot carpet and undo the screws holding down the plastic circle underneath, at least on a golf this is were you can pull out both the in tank pump and float/sender unit, you should be able to see if its broken/sticky not operating correctly.

 

Hope this helps :)

 

Dan

[Critical_Mass 10]

:salute: I'll give it a try dan.. cheers.

 

Trying to work out whether the problem is the gauge or whether its just 2 seperate problems which are both showing on the gauge. :scratch:

 

oh and the gauge has been dropping relatively quickly, only done about 35 miles of steady driving and the gauge had dropped to the next line down already! :(

[Critical_Mass 10]

Anyone got any suggestions with the temp gauge.

 

Can the temp senders on the front of the engine be done without moving anything from the car... ie front of car or inlet manifold etc will i be able to get the clips that hold the senders in place out?

[Critical_Mass 10]

Come on guys, someone must be able to give me a little more advise? :lol:

[Critical_Mass 10]

Right, tonight it appears the heaters will only get warm and will not get hot. Even when i've been driving the car for a while. Now, when i got home i put the bonnet up and felt the top hose for the radiator although it was hot to a certain extent i was able to grab hold of the hose. As with all VRs they get HOT, but i couldnt feel much heat coming from the engine i was able to touch parts with bare hand, that i wouldnt normally be able to touch. However the hoses for the heater matrix did seem hot.

 

Could this be a stuck thermostat? Which would also explain the bad gauge reading????

 

It was replaced when the engine was put in - jan 08. So seems odd that it will be faulty. Also this may explain the terrible fuel consumption.

 

HELP PLEASE! :(

[fla 9]

looks that way. Rather than changing the stat, have you drained and flushed the cooling system? If the stat is new it may just have got jammed with some crud in the system. A good flush will sort this out. Get hold of some of the orange coolant flush from VW this will remove any deposit and residue in the system. iirc its about £25 for a bottle.

[Critical_Mass 10]

looks that way. Rather than changing the stat, have you drained and flushed the cooling system? If the stat is new it may just have got jammed with some crud in the system. A good flush will sort this out. Get hold of some of the orange coolant flush from VW this will remove any deposit and residue in the system. iirc its about £25 for a bottle.

 

Ok probably best to try that first. Problem is, if it doesnt solve it. I'lll have to use more coolant to top the level back once i've replaced the thermostat.