Overheating no roostertail nothing clogged in the inpeller

Check for a clogged radiator. Also check for proper fan operation. Do not mess with the cap. That has nothing to do with overheating.

First the dash gauge is not that accurate. Yes if you have excessive back pressure from the catalytic converter then the temperature can rise on the engine.

wild guess , clogged rad tubes.
wild guess 2, pump impeller , rusted to near nothing
lots more,,, why guess, get the car serviced.

Overheating is caused by the following:
1. Defective thermostat
2. Clogged radiator with deposits due to age
3. Antifreeze that has not been changed for several years
The ported vacuum switch has nothing to do with the cooling system of your car. It just controls when vacuum gets to a particular part or not.

The lower hose shouldn't be as hot as the top. If your not having overheat problems I wouldn't worry about it. If the radiator was clogged, it would overheat.

post all signs of overheating.

1. dash guage
2. STEAM eruptions>?
3. AF (antifreeze ) leaks?
4. CHeck engine light sticks on running?
5. Scan tool shows way hotter than 200F? "ECT PID" parameter.
6. oil in the AF? cold you see oil floating in the neck of the rad cap off?
7. AF found on the A/T tranny dip stick end?
8. Loosing coolant (drops) all the time, Check rad directly cold.?
9. engine pings, (knock/detonation) ?
10. lost power. from engine.
11. shaking of engine. as it misfires.
12. car heater makes this odd gurgling sound?

those are the signs but. what about precondtions.
overheats only parked< and never moving fast>
yes, bad RAD fan, (or its controls)
over heats all the time>?
fan belt fell off or slips?
clogged, rad tubes. (inside)?
water pump bad, blades, rusted to nothing.?
thermostat died, as most do way before 10 years,,,,,,,
clogged system from not doing the 2year service.

2 things,radiator partially clogged,and/or bad heater core.Fan clutch could also be bad.

Possible fan clutch..Usually if its a fan clutch it will run hot sitting still but cool off once going down the road..If it takes a while to run hott then i would suspect a clogged radiator..When you drain it did it look like all the antifreeze came out..Ive seen half the radiater clogged up where half of it drained but the clogged section stay in the radiator

Make sure radiator fan is working....if not check fan fuse, if fuse is good check fan relay, if relay is good fan motor may be bad, replace
Also, may need to change thermostat.
Check coolant levels

Hi Lori . Sorry but it sounds like your water pump inpeller (The internal part that circulates the water) has broken off or come lose . But i would recomend changing the cambelt and tensioner as well . Regards VW Audi tech