Strange overheating issue

Hey everybudy need a little help. I’ve just had a strange overheat thing happen. The car’s been running great for 4 years since I got it (2003 Passat 1.8t with chip), while driving in a pretty hilly area today the coolant temp gauge started to rise on any thing that was an uphill. I didn’t notice it at first but I got the red coolant light and a STOP message in the dash I immediately pushed the clutch in and dropped the engine to idle and looked for a spot to turn off the road. Maybe 5-10 seconds later I was able to roll to a stop and I noticed the coolant gauge around 220F-230F as I shut it down. The gauge has never deviated from 190F no matter how hard or how big a hill or mountain I raced up and only while engine breaking down a long runs does it ever go below 190F after the engine is at operating temp. I assumed a coolant leak but the level was fine and no smell.

After reading the manual and leaving it off for about 5 minutes I decided to start it again thinking it was just a false low level warning. The coolant was right at 190F so I drove a few miles and it seamed normal but the first hill I climbed the temp creeped up and approached the red line. I slowed down and as soon as I started to coast down the other side the temp dropped. I blasted the heat and drove the 40 miles home with the coolant climbing on every up hill and being fine if I drove slow (30-40 mph) on level ground, or downhill or while idling. The outside air was say 50F. The electric rad fan doesn’t seem to come on and the clutched one doesn’t look like it’s turning too fast. A real weird thing though was a few times with the coolant say 220F-ish the air coming out of the hot air vents wasn’t so hot.

Is this just a kaput rad fan or is my water pump not moving fluid or is it something else? The car still idles dead smooth and it has plenty of power so I’m hoping I haven’t F’d it up.

Any help appreciated.


Start with simple things, first: change the thermostat. amd change the coolant. If the electric cooling fan isn’t coming on, it could be the fan relay. Either check it, or, replace it.
If there is still a cooling problem, troubleshooting is needed — including a cooling system pressure check.

Where Are You Checking The Coolant Level?

Are you checking the coolant by looking at the resevoir? Does your car have a radiator cap? Have you checked it there with the engine cold?

High engine coolant temperature and low cabin heat temperature are classic signs of low coolant in the cooling system and / or air trapped in the system.

I wouldn’t drive it until I had it checked out. You need to verify that the engine temperature is actually high, and that the cooling system is full, purged of air, cooling fans working, etcetera.

You could be damaging or further damaging the engine by continuing to run it.

I hope the head gasket is intact. There is a chance that a defective head gasket is the source of your trouble.