Coolant temp a steady 105 Deg?

[laketahoequattro]

On my engine the thermostat is in the front of the engine right below the v next to the water pump. Yes the t-stat is on the heater pipe that connects the heads. No, once I start the car it does take 5 minutes of driving or maybe 10 minutes of idle for the temp gauge to go up to 100-105degC.

Yes the top hose is very hot, I measured it with a thermocouple and it was 98degC. The vehicle is not actually overheating at all thankfully. No spillage or anything like you are describing thank god.

I also replaced every single "smaller bore" breather hose/pipe when I did my engine pull. I can also see bubbles/fluid venting into the expansion tank thru the breather pipe on the top of the expansion tank.

[laketahoequattro]

Do you know how to perform an output test on the aux heater? Tonight I turned on the heater when the car was up to temp and can only get "warm" air to come out of the vents if I have the fan at 5 clicks. Any higher it just blows regular air. I dont think the cores are getting enough heat. Also The aux water pump solenoids are not clicking. I can not feel them pulsing when I touch them. Both of the heater hoses going into the aux pump are hot, after the aux pump the upper hoses on each heater core are cooler than the lower hoses, but the upper hoses are still warm.

When I turn off the car and activate the "rest" function I can hear the pump pumping. Who knows if it is actually pumping or not, but I can hear the motor engage...

As well when I turned off the car and touched the radiator thru the viscous fan, the top 5" of the radiator fins were as hot as the inlet pipe, below that they were ice cold, the lower 80% of the radiator was cold. All fingers point to radiator? I am going to buy one tomorrow.

If I have a bad aux pump I would love to replace it at the same time. The parts people at the dealer think I am crazy for how many bottles of coolant I buy from them in a month haha.

[oldnick]

hope it's G12or 13

[Mechcanico Lee]

Did you try it with the thermostat removed like i said , for 80% of the radiator to be blocked thats bad , the water will be sillty as hell , normally its sort of the lowest quarter of the rad that gets blocked .

I would run it with no thermostat first and then if the radiator is still cold only then would i replace the rad

[laketahoequattro]

No I did not because I replaced the thermostat with a brand new oem from the dealer. When I initially pulled the engine there was some black crap in the expansion tank. I have to assume that the car had some wrong coolant in it at one time.

Yes it is OEM coolant from the dealer. Pink gold

Any thoughts on the aux pump solenoids not pulsing? Does that determine it is faulty and needs replacement?

[laketahoequattro]

Ok radiator and aux pump are in the mail. Will report back after chemical flush of heater cores and installation of parts. Fingers crossed.

[Mechcanico Lee]

Yes keep us informed , interesting one .

[laketahoequattro]

Flow test of new "used" radiator.

https://youtu.be/InulgpyQXbc

[laketahoequattro]

Wow. Who ever says that this aux pump can be replaced in an hour is a god! Here are some fun pics haha. I unbolted the master cylinder, need to disconnect the pedal, hopefully then the aux pump comes out easy. All the hoses were incredibly difficult to remove. No space! I tried to remove the fan box, it appears to be bolted in from the bottom. I bought a new OE fan clutch but mine is siezed on so that is frustrating me. Any how. Hopefly will have some results by Saturday when I have some time to finish up.





First time digging into the a8 heater stuff so learning experience for me

[ainarssems]

That's because yours is left hand drive, on RHD it is easily accessible and most of the users on this forum are UK based so we do sometimes forget that there differences to be considered for LHD cars.