S60 D5 Cooling issues

[webbyd5]

Originally Posted by 5cilinder

Have you tried to control the temperature with the heater on max blow?
Did you check the radiator at both sides on blockage on airflow etc?

When I turn the heater on max blow the temperature needle moves down to about a 1/4 if left for a while so the heaters are taking temp off of the engine.

Do you suggest I remove the bottom hose and check for blockages?

[webbyd5]

When I last checked the thermostat, I wedged it out of the wat to eliminate it from the system and the pressure was still present. I have since put the thermostat back into position and the pressure is still there. Exactly the same. Maybe the blockage is in the rad somewhere? All very confusing :/

[cheshired5]

Originally Posted by webbyd5

All very confusing

Not really so don't concern yourself too much.
Just do a coolant change using this procedure and your problem will become apparent and be solved.

https://www.youtube.com/watch?v=CMkR...va09m&index=30

[5cilinder]

Originally Posted by webbyd5

When I turn the heater on max blow the temperature needle moves down to about a 1/4 if left for a while so the heaters are taking temp off of the engine.

Do you suggest I remove the bottom hose and check for blockages?

Well if the heater takes enough coolant to take heat away than you can practicly rule out blockage because the other hoses are thicker .
Also all the hot hoses imply circulation
The heatercore is in serial so if the blockage was elsewhere it would also affect the heatercore capacitiy

One exception is the big radiator
If the radiator is partly clogged than the coolantstream can still route/forced through the short circuit within the engineblock (and heatercore)
Check the radiator for even heat distribution if its not even with strange small hotspots than your radiator is internally clogged oxidated
It could also explain the hot returnhose under the radiator there streams some coolant but not enough heat is removed

[webbyd5]

I appear to have sorted this one, not much pressure now. Did a full flush as per cheshired5 video, not much coolant came out a lot of particulate but only around 5 litres of coolant was alls I could manage.
Will let you know how the next few weeks go once I've sorted the bloody turbo issue again!
Cheers

[webbyd5]

Spoke too soon, just went for a 5 mile drive, plenty of revs etc pulled up popped the bonnet and..... pressure and lots of it too...

[webbyd5]

Is the finger pointing to the radiator then? Everything is pressurising at around 84 - 87°c?

[5cilinder]

(again)

Did you check correct operation of the tempsensor? (temp meter in expantionvessel (with sufficient flow))

Did you checkat wich temp the thermostat opens (feeling top hose for sufficient heat (whole hose hot))

Did you check between intercooler and radiaor and intercooler and condenser to check with debris that obstructs airflow?

Did you check the radiator for hotspots? (wich indicate partly clogging) (disconnect the fan to freely feel with you fingers or better infrared laser tempmeter)

[webbyd5]

Hi 5cylinder,

I will check these points and come back to you. My father in law has an infa red lazer thermometer so I will try that this week. I have checked the hose for the thermostat opening and today it doesent seem like it is doing even at 93°c due to the pressure build up.

[cheshired5]

Are you certain that the thermostat is installed correctly?
Brass cylinder in the engine coolant and wobble pin at the top.....