danfil

After last year replacing the timing belt and water pump and the thermostat I am still experiencing slight overheating of the coolant system.

Today I have done another flush after the pink coolant changing colour, I am using a Super Flush to aid in flushing with tap water.

Here is a video of the motor running for the last 7 minutes of a 20 minute flush as for dirty systems.


Something I did not allow for was the actual heating from running as described in video as " thermostat closed ", mentioned a few times.

I recently tonight opened up the rear underside drain plug as part of the flushing. Its blocked again, fun fun fun, if I can unblock it again..

What I am actually worried about is at idle in traffic it gets dangerously hot considering the temperature probe is external to the heater core piping.

danfil

This is what came out after clear water and clear Super Flush went in.

Going to do some more flushing out of coolant water.

Rusty Spokes

Danfil..good work on the cooling system. I had to flush my engine several times too. That rust takes a while to remove.

I am surprised that your engine is running at about 70*C and the fans come on..70*C is really not an overheated condition.

Here is the USA the thermostat were normally set to open at about 89*C . The radiator fan switch would kick the first speed on at 95*C and the high speed fans at 102*C

Using my OBC2 VAG tool, which measures the engine temps from the temp sender for the ECU on the heating pipe behind the heads..my engine temps run between about 90*C to 100*C

If I use an IR gun and check the hoses going to the radiator, I get about 80*C to 90*C at the same time..so my guess is the engine temp sender for the ECU gets much warmer due to its location.

Do you have a lower temp thermostat and radiator fan switch? Your engine temps look low to me. And the temp readings at that hose may not be good if the flow to the heater is partially plugged from rust too. Very strange your fans automatically came on at around 70*C

The Audi dash temp gauge can be misleading as to what is really going on. Normally if they are working correctly the range on the dial is from 10 o'clock to 12 o'clock..




And it looks like you had to make a plug for the bleeder valve on your coolant hose. There is a solution if the hose fitting is stripped out.




Order the brass bleeder from Renault..part number 7700518589 and the rubber seal part number 7703061007. Install those into the hose..they work well. Renault parts can be found on-line. I got mine from Ebay in England for about $20US including shipping.

danfil

thanks rusty for the reply, the heater core is bypassed with a copper elbow since it was cracked at the connector irreparably. I bleed the air out by cracking the hose at the elbow and pressurizing the expansion tank.

I know the heater core is not that expensive but I am not prepared for the dash, console and steering wheel removal to get to the heater core, a days work plus for me.

The thermostat was bought from a euro aftermarket place reasonably local to me, And I assumed it would run the engine as with you close to boiling point of water.

I am refilling with coolant this morning and will run up the car to temp. I did the video since I thought my thermostat was sticking closed then open.

My o.e. temp gauge on the dash is non working.