1.8T FWD. Original thread is <a href="https://forums.audiworld.com/a4/msgs/2463821.phtml">here</a>.

<b>Summary so far...</b>
- Car overheats after a mile or 2 of driving. Water temp goes a couple notches above center, warning light goes on. Found a small leak on the rear "connector" (plastic housing that holds the 4-wire temp sensor), and replaced that along with the sensor (which a vagcom complained about). Water will gurgle (boiling it seems) at the small hose going into the expansion tank at the high temps. But system is almost completely water at this point. When it gurgles, the system loses a noticeable amount of water, but not sure where it's going.

<b>Some diagnosis...</b>
- I can raise the expansion tank and water will come out of the bleed hole on the heater-core hose near the firewall.

- Removed some hoses and I can pour water into the top radiator hose and it will come out the bottom.

- Changed the oil just now to check if there was any sign of coolant, but nope. So blown head gasket is out.

- Fans are not coming on. There is obviously some other problem as well since at 50+mph, the temps will keep rising, so I'm guessing that there may be a flow problem to the radiator and that is keeping the fan temp switch from coming on.

<b>So it seems I'm down to three things...</b>
(1) Clogged hose elsewhere -- the hard tube that comes from the back of the engine (attached to that connector I changed) and leading to the top radiator hose, may be clogged.

(2) Stuck thermostat -- I have it here now and looking for a sacrificial pot to boil it in and test it. But I'm wondering if I can run the car without a thermostat to test if it will not overheat?

(3) Water pump (I really dread this). I have a replacement water pump which I ordered when I did my timing belt &amp; tensioner change a couple years ago, but it arrived after the belt swap. I'm really really hoping it's the thermostat though, cause it would be an unpleasant christmas otherwise.

Question -- if I pour water into the hard tube leading to the connector at back of the motor, would I get water coming out where the thermostat is (with the thermostat removed)? Or would the water pump block it when not running? I do not have the option of using a hose/pressure since I'm in an apartment complex with a detached garage.

As always, thoughts/assistance appreciated and much thanks for the help.

Cheers,
-Neil.

 

Put the thermostat in boiling water and it opened right up! Looks a bit grungy so wondering if perhaps it was stuck? When I was removing it, I pushed up on the moveable part with a screwdriver to drain the water out of the pump first, so perhaps I unstuck at that time?

Other option -- perhaps after I changed the rear connector and lost a lot of water, there was an air pocket at the thermostat housing connector that was preventing water from getting to it, and hence preventing the thermostat from opening? This would've meant there would never be any water flow to get the thermostat open in the first place.

Yes, I'm trying to find anything else wrong with it other than the water pump. :-(

Cheers,
-Neil.

 

BTW, what's the best way to test the water pump while it's in the car?

 

also thermo can be installed backwards so make sure you get it in the right way.

why are you looking at things other then the water pump?

 

2nd. He's in denial... it's the water pump.

 

&gt; why are you looking at things other then the water pump?

Cause it's a freakin' nightmare to change, while I'm in an apartment that already has issues with me doing things like oil changes, etc, even if it is inside a garage.

Plus the time involved, and many of my tools are still in boxes.

And yes, if I do run into something that I need a part for, it's a bad weekend to get anything, or to get someone to give me a ride there.


-Neil.

 

Then hire someone you whining b&amp;*%.

 

Yep. Bigtime denial.

 

Not on Christmas weekend.

 

You're really missing my point.