Golf R overheating - help required

[zu11y]

Hi guys,

i have a golf R in our workshop, the customer reports that the cars temp gauge is showing overheating when driven hard.

i have driven the car and replicated the problem, however on live data the engine temp is within in normal range. i.e goes up to around 93 then the fans kick in bringing it back down.

a quick scan is giving two faults.

1st it is showing the coolant level sensor has an electrical malfunction.

2nd it is showing the coolant bypass valve to have an open circuit.


anyone come across this sort of issue, who could point me in the right direction.

[niall campbell]

change the coolant temp sender unit with a genuine one, what the dash says doesn't always reflect with the engine temp

change the bypass valve as well if faulty


that's what I would do and get the customer to come back if problem still exists

[zu11y]

Hi cheers for the reply,

is the coolant temp sender unit different to a temp sensor?

as the reading via live data for the temp sensor indicate it is working fine

[niall campbell]

when you replicate the fault, what does dash say compared to live data ?

[zu11y]

Hi the dash gauge is showing between 10-15 degrees more than the temp sensor through the drive. highest the dash showed was 115 whilst the temp sensor showed 98 and then dropped down when the fans came on

[zu11y]

update-

replaced the coolant level sensor and all is good now

[zollaf]

how did you get to that diagnosis ?

[zu11y]

well it was one of the fault codes showing, wiring checked out. was quite cheap to replace and customer was happy to replace.

[niall campbell]

sometimes you have to trust the diagnostics