Overheating or not??

[JP2021]

Driving into work today through some horrendous traffic, I had a peculiar moment whilst stuck in a jam. All was fine until I glanced down to the dash and saw the dreaded exclamation mark alight. Immediately looking towards the temperature gauge I saw the needle was almost touching red, something that I've never had before. I then flicked to see the oil temperature which read 109 degrees, which didn't seem excessive.

At this point, whilst still stationary in traffic, I switched off the engine with some trepidation as to what to expect next. 30 seconds later I started the engine and the temperature gauge went straight to the usual 90 degrees, the explanation mark gone and all was fine for the rest of the drive. However, on parking and stationary the temperature gauge again read just off red. I switched off the engine, restarted and again all was fine with oil temperature reading 100 degrees.

Has anyone else experienced this? Is the analogue temperature dial directly connected to the temperature sensor and if so, why the huge change in reading after having the engine off for just 30 seconds? Also, wouldn't the oil temperature rise excessively in line with the water temperature? Lastly, there is obviously a problem, any idea what it may be?

[clubsport]

These are the symptoms of the dreaded thermostat housing issue, if you are lucky, it may well be a temperature sensor playing up. The only way to check is with an OBD reader to analyse the codes which are shown, hope you have a warranty?

[JP2021]

Alas not in warranty as a 2014 model! I do have an OBD reader and have checked the fault codes, the engine fault reading 'Engine Coolant Flow Low/Performance'. The expansion tank is showing no signs of loss of coolant?

[symonh2000]

With the engine running and the expansion tank cap off can you see the coolant moving about?

If not it could be a failed waterpump, or the little belt which drives it.

Has anyone ever had the little belt snap yet? it seems a bit of a fragile design by looking at it.

[Finglonga]

Put your aircon on and see if the Fans are working they should both come on. Never had the temperature rise with any on my water pump/thermostat housing leaks.

Also worth looking if the Oil temperature has risen as well if it happens again.

[theminty1]

Agree about the fan check, I have a mk5 Golf and the temperature went up in traffic past the normal 90degrees. Turned out neither of the two fans were working. Replaced both fans, now no issues. I got vw original parts and fitted myself. Pricey but they work:)

[Carbon VW]

It’s the thermostat housing.

[JP2021]

So I drove home last night, 60 miles on M25 and a few on country lanes (no traffic) and rock steady 90 degrees and oil temperature an average of 107 degrees. Drove to work today, 30 miles country lanes (no traffic), again all fine. All fans operate and can't see anything strange. The weird thing that doesn't make much sense is that when it happened yesterday, the analogue temperature gauge read one notch off red with oil temperature of 110 degrees. Switching the engine off for 30 seconds whilst in traffic, on restarting the analogue temperature gauge went straight to 90 degrees and stayed there, wouldn't have read higher and gradually dropped? It was almost like a sensor was feeding the analogue dial and on restoring the engine it kicked the sensor back to normality? Make sense??

[joe6]

I had something similar a whilea ago that eventually was diagnosed as a sensor. Did not have any error code initially.

[Carbon VW]

You do understand that the analogue gauge is the coolant temperature, and tje digital readout is oil temperature ? A lot of people think they are the same thing. Get it checked out by a good independent garage. I’m pretty sure it’s the thermostat housing issue.